This is xnu-11215.1.10. See this file in:
/*
* Copyright (c) 2000-2020 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <vm/vm_compressor_internal.h>
#if CONFIG_PHANTOM_CACHE
#include <vm/vm_phantom_cache_internal.h>
#endif
#include <vm/vm_map_xnu.h>
#include <vm/vm_pageout_xnu.h>
#include <vm/vm_map_internal.h>
#include <vm/memory_object.h>
#include <vm/vm_compressor_algorithms_internal.h>
#include <vm/vm_compressor_backing_store_internal.h>
#include <vm/vm_fault.h>
#include <vm/vm_protos.h>
#include <vm/vm_kern_xnu.h>
#include <vm/vm_compressor_pager_internal.h>
#include <vm/vm_iokit.h>
#include <mach/mach_host.h> /* for host_info() */
#if DEVELOPMENT || DEBUG
#include <kern/hvg_hypercall.h>
#include <vm/vm_compressor_info.h> /* for c_segment_info */
#endif
#include <kern/ledger.h>
#include <kern/policy_internal.h>
#include <kern/thread_group.h>
#include <san/kasan.h>
#include <os/atomic_private.h>
#include <os/log.h>
#include <pexpert/pexpert.h>
#include <pexpert/device_tree.h>
#if defined(__x86_64__)
#include <i386/misc_protos.h>
#endif
#if defined(__arm64__)
#include <arm/machine_routines.h>
#endif
#include <IOKit/IOHibernatePrivate.h>
/*
* The segment buffer size is a tradeoff.
* A larger buffer leads to faster I/O throughput, better compression ratios
* (since fewer bytes are wasted at the end of the segment),
* and less overhead (both in time and space).
* However, a smaller buffer causes less swap when the system is overcommited
* b/c a higher percentage of the swapped-in segment is definitely accessed
* before it goes back out to storage.
*
* So on systems without swap, a larger segment is a clear win.
* On systems with swap, the choice is murkier. Empirically, we've
* found that a 64KB segment provides a better tradeoff both in terms of
* performance and swap writes than a 256KB segment on systems with fast SSDs
* and a HW compression block.
*/
#define C_SEG_BUFSIZE_ARM_SWAP (1024 * 64)
#if XNU_TARGET_OS_OSX && defined(__arm64__)
#define C_SEG_BUFSIZE_DEFAULT C_SEG_BUFSIZE_ARM_SWAP
#else
#define C_SEG_BUFSIZE_DEFAULT (1024 * 256)
#endif /* TARGET_OS_OSX && defined(__arm64__) */
uint32_t c_seg_bufsize;
uint32_t c_seg_max_pages; /* maximum number of pages the compressed data of a segment can take */
uint32_t c_seg_off_limit; /* if we've reached this size while filling the segment, don't bother trying to fill anymore
* because it's unlikely to succeed */
uint32_t c_seg_allocsize, c_seg_slot_var_array_min_len;
extern boolean_t vm_darkwake_mode;
extern zone_t vm_page_zone;
#if DEVELOPMENT || DEBUG
/* sysctl defined in bsd/dev/arm64/sysctl.c */
static event_t debug_cseg_wait_event = NULL;
#endif /* DEVELOPMENT || DEBUG */
#if CONFIG_FREEZE
bool freezer_incore_cseg_acct = TRUE; /* Only count incore compressed memory for jetsams. */
#endif /* CONFIG_FREEZE */
#if POPCOUNT_THE_COMPRESSED_DATA
boolean_t popcount_c_segs = TRUE;
static inline uint32_t
vmc_pop(uintptr_t ins, int sz)
{
uint32_t rv = 0;
if (__probable(popcount_c_segs == FALSE)) {
return 0xDEAD707C;
}
while (sz >= 16) {
uint32_t rv1, rv2;
uint64_t *ins64 = (uint64_t *) ins;
uint64_t *ins642 = (uint64_t *) (ins + 8);
rv1 = __builtin_popcountll(*ins64);
rv2 = __builtin_popcountll(*ins642);
rv += rv1 + rv2;
sz -= 16;
ins += 16;
}
while (sz >= 4) {
uint32_t *ins32 = (uint32_t *) ins;
rv += __builtin_popcount(*ins32);
sz -= 4;
ins += 4;
}
while (sz > 0) {
char *ins8 = (char *)ins;
rv += __builtin_popcount(*ins8);
sz--;
ins++;
}
return rv;
}
#endif
#if VALIDATE_C_SEGMENTS
boolean_t validate_c_segs = TRUE;
#endif
/*
* vm_compressor_mode has a hierarchy of control to set its value.
* boot-args are checked first, then device-tree, and finally
* the default value that is defined below. See vm_fault_init() for
* the boot-arg & device-tree code.
*/
#if !XNU_TARGET_OS_OSX
#if CONFIG_FREEZE
int vm_compressor_mode = VM_PAGER_FREEZER_DEFAULT;
struct freezer_context freezer_context_global;
#else /* CONFIG_FREEZE */
int vm_compressor_mode = VM_PAGER_NOT_CONFIGURED;
#endif /* CONFIG_FREEZE */
#else /* !XNU_TARGET_OS_OSX */
int vm_compressor_mode = VM_PAGER_COMPRESSOR_WITH_SWAP;
#endif /* !XNU_TARGET_OS_OSX */
TUNABLE(uint32_t, vm_compression_limit, "vm_compression_limit", 0);
int vm_compressor_is_active = 0;
int vm_compressor_available = 0;
extern uint64_t vm_swap_get_max_configured_space(void);
extern void vm_pageout_io_throttle(void);
#if CHECKSUM_THE_DATA || CHECKSUM_THE_SWAP || CHECKSUM_THE_COMPRESSED_DATA
extern unsigned int hash_string(char *cp, int len);
static unsigned int vmc_hash(char *, int);
boolean_t checksum_c_segs = TRUE;
unsigned int
vmc_hash(char *cp, int len)
{
unsigned int result;
if (__probable(checksum_c_segs == FALSE)) {
return 0xDEAD7A37;
}
vm_memtag_disable_checking();
result = hash_string(cp, len);
vm_memtag_enable_checking();
return result;
}
#endif
#define UNPACK_C_SIZE(cs) ((cs->c_size == (PAGE_SIZE-1)) ? PAGE_SIZE : cs->c_size)
#define PACK_C_SIZE(cs, size) (cs->c_size = ((size == PAGE_SIZE) ? PAGE_SIZE - 1 : size))
struct c_sv_hash_entry {
union {
struct {
uint32_t c_sv_he_ref;
uint32_t c_sv_he_data;
} c_sv_he;
uint64_t c_sv_he_record;
} c_sv_he_un;
};
#define he_ref c_sv_he_un.c_sv_he.c_sv_he_ref
#define he_data c_sv_he_un.c_sv_he.c_sv_he_data
#define he_record c_sv_he_un.c_sv_he_record
#define C_SV_HASH_MAX_MISS 32
#define C_SV_HASH_SIZE ((1 << 10))
#define C_SV_HASH_MASK ((1 << 10) - 1)
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
#define C_SV_CSEG_ID ((1 << 21) - 1)
#else /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
#define C_SV_CSEG_ID ((1 << 22) - 1)
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
/* elements of c_segments array */
union c_segu {
c_segment_t c_seg;
uintptr_t c_segno; /* index of the next element in the segments free-list, c_free_segno_head is the head */
};
#define C_SLOT_ASSERT_PACKABLE(ptr) \
VM_ASSERT_POINTER_PACKABLE((vm_offset_t)(ptr), C_SLOT_PACKED_PTR);
#define C_SLOT_PACK_PTR(ptr) \
VM_PACK_POINTER((vm_offset_t)(ptr), C_SLOT_PACKED_PTR)
#define C_SLOT_UNPACK_PTR(cslot) \
(c_slot_mapping_t)VM_UNPACK_POINTER((cslot)->c_packed_ptr, C_SLOT_PACKED_PTR)
/* for debugging purposes */
SECURITY_READ_ONLY_EARLY(vm_packing_params_t) c_slot_packing_params =
VM_PACKING_PARAMS(C_SLOT_PACKED_PTR);
uint32_t c_segment_count = 0; /* count all allocated c_segments in all queues */
uint32_t c_segment_count_max = 0; /* maximum c_segment_count has ever been */
uint64_t c_generation_id = 0;
uint64_t c_generation_id_flush_barrier;
#define HIBERNATE_FLUSHING_SECS_TO_COMPLETE 120
boolean_t hibernate_no_swapspace = FALSE;
boolean_t hibernate_flush_timed_out = FALSE;
clock_sec_t hibernate_flushing_deadline = 0;
#if RECORD_THE_COMPRESSED_DATA
/* buffer used as an intermediate stage before writing to file */
char *c_compressed_record_sbuf; /* start */
char *c_compressed_record_ebuf; /* end */
char *c_compressed_record_cptr; /* next buffered write */
#endif
/* the different queues a c_segment can be in via c_age_list */
queue_head_t c_age_list_head;
queue_head_t c_early_swappedin_list_head, c_regular_swappedin_list_head, c_late_swappedin_list_head;
queue_head_t c_early_swapout_list_head, c_regular_swapout_list_head, c_late_swapout_list_head;
queue_head_t c_swapio_list_head;
queue_head_t c_swappedout_list_head;
queue_head_t c_swappedout_sparse_list_head;
queue_head_t c_major_list_head;
queue_head_t c_filling_list_head;
queue_head_t c_bad_list_head;
/* count of each of the queues above */
uint32_t c_age_count = 0;
uint32_t c_early_swappedin_count = 0, c_regular_swappedin_count = 0, c_late_swappedin_count = 0;
uint32_t c_early_swapout_count = 0, c_regular_swapout_count = 0, c_late_swapout_count = 0;
uint32_t c_swapio_count = 0;
uint32_t c_swappedout_count = 0;
uint32_t c_swappedout_sparse_count = 0;
uint32_t c_major_count = 0;
uint32_t c_filling_count = 0;
uint32_t c_empty_count = 0;
uint32_t c_bad_count = 0;
/* a c_segment can be in the minor-compact queue as well as one of the above ones, via c_list */
queue_head_t c_minor_list_head;
uint32_t c_minor_count = 0;
int c_overage_swapped_count = 0;
int c_overage_swapped_limit = 0;
int c_seg_fixed_array_len; /* number of slots in the c_segment inline slots array */
union c_segu *c_segments; /* array of all c_segments, not all of it may be populated */
vm_offset_t c_buffers; /* starting address of all compressed data pointed to by c_segment.c_store.c_buffer */
vm_size_t c_buffers_size; /* total size allocated in c_buffers */
caddr_t c_segments_next_page; /* next page to populate for extending c_segments */
boolean_t c_segments_busy;
uint32_t c_segments_available; /* how many segments are in populated memory (used or free), populated size of c_segments array */
uint32_t c_segments_limit; /* max size of c_segments array */
uint32_t c_segments_nearing_limit;
uint32_t c_segment_svp_in_hash;
uint32_t c_segment_svp_hash_succeeded;
uint32_t c_segment_svp_hash_failed;
uint32_t c_segment_svp_zero_compressions;
uint32_t c_segment_svp_nonzero_compressions;
uint32_t c_segment_svp_zero_decompressions;
uint32_t c_segment_svp_nonzero_decompressions;
uint32_t c_segment_noncompressible_pages;
uint32_t c_segment_pages_compressed = 0; /* Tracks # of uncompressed pages fed into the compressor, including SV (single value) pages */
#if CONFIG_FREEZE
int32_t c_segment_pages_compressed_incore = 0; /* Tracks # of uncompressed pages fed into the compressor that are in memory */
int32_t c_segment_pages_compressed_incore_late_swapout = 0; /* Tracks # of uncompressed pages fed into the compressor that are in memory and tagged for swapout */
uint32_t c_segments_incore_limit = 0; /* Tracks # of segments allowed to be in-core. Based on compressor pool size */
#endif /* CONFIG_FREEZE */
uint32_t c_segment_pages_compressed_limit;
uint32_t c_segment_pages_compressed_nearing_limit;
uint32_t c_free_segno_head = (uint32_t)-1; /* head of free list of c_segment pointers in c_segments */
uint32_t vm_compressor_minorcompact_threshold_divisor = 10;
uint32_t vm_compressor_majorcompact_threshold_divisor = 10;
uint32_t vm_compressor_unthrottle_threshold_divisor = 10;
uint32_t vm_compressor_catchup_threshold_divisor = 10;
uint32_t vm_compressor_minorcompact_threshold_divisor_overridden = 0;
uint32_t vm_compressor_majorcompact_threshold_divisor_overridden = 0;
uint32_t vm_compressor_unthrottle_threshold_divisor_overridden = 0;
uint32_t vm_compressor_catchup_threshold_divisor_overridden = 0;
#define C_SEGMENTS_PER_PAGE (PAGE_SIZE / sizeof(union c_segu))
LCK_GRP_DECLARE(vm_compressor_lck_grp, "vm_compressor");
LCK_RW_DECLARE(c_master_lock, &vm_compressor_lck_grp);
LCK_MTX_DECLARE(c_list_lock_storage, &vm_compressor_lck_grp);
boolean_t decompressions_blocked = FALSE;
zone_t compressor_segment_zone;
int c_compressor_swap_trigger = 0;
uint32_t compressor_cpus;
char *compressor_scratch_bufs;
struct vm_compressor_kdp_state vm_compressor_kdp_state;
clock_sec_t start_of_sample_period_sec = 0;
clock_nsec_t start_of_sample_period_nsec = 0;
clock_sec_t start_of_eval_period_sec = 0;
clock_nsec_t start_of_eval_period_nsec = 0;
uint32_t sample_period_decompression_count = 0;
uint32_t sample_period_compression_count = 0;
uint32_t last_eval_decompression_count = 0;
uint32_t last_eval_compression_count = 0;
#define DECOMPRESSION_SAMPLE_MAX_AGE (60 * 30)
boolean_t vm_swapout_ripe_segments = FALSE;
uint32_t vm_ripe_target_age = (60 * 60 * 48);
uint32_t swapout_target_age = 0;
uint32_t age_of_decompressions_during_sample_period[DECOMPRESSION_SAMPLE_MAX_AGE];
uint32_t overage_decompressions_during_sample_period = 0;
void do_fastwake_warmup(queue_head_t *, boolean_t);
boolean_t fastwake_warmup = FALSE;
boolean_t fastwake_recording_in_progress = FALSE;
uint64_t dont_trim_until_ts = 0;
uint64_t c_segment_warmup_count;
uint64_t first_c_segment_to_warm_generation_id = 0;
uint64_t last_c_segment_to_warm_generation_id = 0;
boolean_t hibernate_flushing = FALSE;
_Atomic uint64_t c_segment_input_bytes = 0;
_Atomic uint64_t c_segment_compressed_bytes = 0;
_Atomic uint64_t compressor_bytes_used = 0;
/* Keeps track of the most recent timestamp for when major compaction finished. */
mach_timespec_t major_compact_ts;
struct c_sv_hash_entry c_segment_sv_hash_table[C_SV_HASH_SIZE] __attribute__ ((aligned(8)));
static void vm_compressor_swap_trigger_thread(void);
static void vm_compressor_do_delayed_compactions(boolean_t);
static void vm_compressor_compact_and_swap(boolean_t);
static void vm_compressor_process_regular_swapped_in_segments(boolean_t);
static void vm_compressor_process_special_swapped_in_segments_locked(void);
struct vm_compressor_swapper_stats vmcs_stats;
static void vm_compressor_process_major_segments(bool);
#if XNU_TARGET_OS_OSX
static void vm_compressor_take_paging_space_action(void);
#endif /* XNU_TARGET_OS_OSX */
void compute_swapout_target_age(void);
boolean_t c_seg_major_compact(c_segment_t, c_segment_t);
boolean_t c_seg_major_compact_ok(c_segment_t, c_segment_t);
int c_seg_minor_compaction_and_unlock(c_segment_t, boolean_t);
int c_seg_do_minor_compaction_and_unlock(c_segment_t, boolean_t, boolean_t, boolean_t);
void c_seg_try_minor_compaction_and_unlock(c_segment_t c_seg);
void c_seg_move_to_sparse_list(c_segment_t);
void c_seg_insert_into_q(queue_head_t *, c_segment_t);
uint64_t vm_available_memory(void);
/*
* indicate the need to do a major compaction if
* the overall set of in-use compression segments
* becomes sparse... on systems that support pressure
* driven swapping, this will also cause swapouts to
* be initiated.
*/
static bool
vm_compressor_needs_to_major_compact(void)
{
uint32_t incore_seg_count;
incore_seg_count = c_segment_count - c_swappedout_count - c_swappedout_sparse_count;
/* second condition:
* first term:
* - (incore_seg_count * c_seg_max_pages) is the maximum size that is this number of segments can hold in the buffer
* - VM_PAGE_COMPRESSOR_COUNT is the current size that is actually held by the buffers
* -- subtracting these gives the amount of pages that is wasted as holes due to segments not be full
* second term:
* - 1/8 of the maximum size that can be held by this many segments
* meaning of the comparison: is the ratio of wasted space greated than 1/8
* first condition:
* compare number of segments being used vs the number of segments that can ever be allocated
* if we don't have a lot of data in the compressor, then we don't need to bother caring about wasted space in holes
*/
if ((c_segment_count >= (c_segments_nearing_limit / 8)) &&
((incore_seg_count * c_seg_max_pages) - VM_PAGE_COMPRESSOR_COUNT) >
((incore_seg_count / 8) * c_seg_max_pages)) {
return true;
}
return false;
}
TUNABLE_WRITEABLE(uint64_t, vm_compressor_minor_fragmentation_threshold_pct, "vm_compressor_minor_frag_threshold_pct", 10);
static bool
vm_compressor_needs_to_minor_compact(void)
{
uint32_t compactible_seg_count = os_atomic_load(&c_minor_count, relaxed);
if (compactible_seg_count == 0) {
return false;
}
bool is_pressured = AVAILABLE_NON_COMPRESSED_MEMORY <
VM_PAGE_COMPRESSOR_COMPACT_THRESHOLD;
if (!is_pressured) {
return false;
}
uint64_t bytes_used = os_atomic_load(&compressor_bytes_used, relaxed);
uint64_t bytes_total = VM_PAGE_COMPRESSOR_COUNT * PAGE_SIZE_64;
uint64_t bytes_frag = bytes_total - bytes_used;
bool is_fragmented = bytes_frag >
bytes_total * vm_compressor_minor_fragmentation_threshold_pct / 100;
return is_fragmented;
}
uint64_t
vm_available_memory(void)
{
return ((uint64_t)AVAILABLE_NON_COMPRESSED_MEMORY) * PAGE_SIZE_64;
}
uint32_t
vm_compressor_pool_size(void)
{
return VM_PAGE_COMPRESSOR_COUNT;
}
uint32_t
vm_compressor_fragmentation_level(void)
{
const uint32_t incore_seg_count = c_segment_count - c_swappedout_count - c_swappedout_sparse_count;
if ((incore_seg_count == 0) || (c_seg_max_pages == 0)) {
return 0;
}
return 100 - (vm_compressor_pool_size() * 100 / (incore_seg_count * c_seg_max_pages));
}
uint32_t
vm_compression_ratio(void)
{
if (vm_compressor_pool_size() == 0) {
return UINT32_MAX;
}
return c_segment_pages_compressed / vm_compressor_pool_size();
}
uint64_t
vm_compressor_pages_compressed(void)
{
return c_segment_pages_compressed * PAGE_SIZE_64;
}
bool
vm_compressor_compressed_pages_nearing_limit(void)
{
uint32_t pages = 0;
#if CONFIG_FREEZE
pages = os_atomic_load(&c_segment_pages_compressed_incore, relaxed);
#else /* CONFIG_FREEZE */
pages = c_segment_pages_compressed;
#endif /* CONFIG_FREEZE */
return pages > c_segment_pages_compressed_nearing_limit;
}
static bool
vm_compressor_segments_nearing_limit(void)
{
uint64_t segments;
#if CONFIG_FREEZE
if (freezer_incore_cseg_acct) {
if (os_sub_overflow(c_segment_count, c_swappedout_count, &segments)) {
segments = 0;
}
if (os_sub_overflow(segments, c_swappedout_sparse_count, &segments)) {
segments = 0;
}
} else {
segments = os_atomic_load(&c_segment_count, relaxed);
}
#else /* CONFIG_FREEZE */
segments = c_segment_count;
#endif /* CONFIG_FREEZE */
return segments > c_segments_nearing_limit;
}
boolean_t
vm_compressor_low_on_space(void)
{
return vm_compressor_compressed_pages_nearing_limit() ||
vm_compressor_segments_nearing_limit();
}
boolean_t
vm_compressor_out_of_space(void)
{
#if CONFIG_FREEZE
uint64_t incore_seg_count;
uint32_t incore_compressed_pages;
if (freezer_incore_cseg_acct) {
if (os_sub_overflow(c_segment_count, c_swappedout_count, &incore_seg_count)) {
incore_seg_count = 0;
}
if (os_sub_overflow(incore_seg_count, c_swappedout_sparse_count, &incore_seg_count)) {
incore_seg_count = 0;
}
incore_compressed_pages = os_atomic_load(&c_segment_pages_compressed_incore, relaxed);
} else {
incore_seg_count = os_atomic_load(&c_segment_count, relaxed);
incore_compressed_pages = os_atomic_load(&c_segment_pages_compressed_incore, relaxed);
}
if ((incore_compressed_pages >= c_segment_pages_compressed_limit) ||
(incore_seg_count > c_segments_incore_limit)) {
return TRUE;
}
#else /* CONFIG_FREEZE */
if ((c_segment_pages_compressed >= c_segment_pages_compressed_limit) ||
(c_segment_count >= c_segments_limit)) {
return TRUE;
}
#endif /* CONFIG_FREEZE */
return FALSE;
}
bool
vm_compressor_is_thrashing()
{
compute_swapout_target_age();
if (swapout_target_age) {
c_segment_t c_seg;
lck_mtx_lock_spin_always(c_list_lock);
if (!queue_empty(&c_age_list_head)) {
c_seg = (c_segment_t) queue_first(&c_age_list_head);
if (c_seg->c_creation_ts > swapout_target_age) {
swapout_target_age = 0;
}
}
lck_mtx_unlock_always(c_list_lock);
}
return swapout_target_age != 0;
}
int
vm_wants_task_throttled(task_t task)
{
ledger_amount_t compressed;
if (task == kernel_task) {
return 0;
}
if (VM_CONFIG_SWAP_IS_ACTIVE) {
if ((vm_compressor_low_on_space() || HARD_THROTTLE_LIMIT_REACHED())) {
ledger_get_balance(task->ledger, task_ledgers.internal_compressed, &compressed);
compressed >>= VM_MAP_PAGE_SHIFT(task->map);
if ((unsigned int)compressed > (c_segment_pages_compressed / 4)) {
return 1;
}
}
}
return 0;
}
#if DEVELOPMENT || DEBUG
/*
* On compressor/swap exhaustion, kill the largest process regardless of
* its chosen process policy.
*/
TUNABLE(bool, kill_on_no_paging_space, "-kill_on_no_paging_space", false);
#endif /* DEVELOPMENT || DEBUG */
#if CONFIG_JETSAM
boolean_t memorystatus_kill_on_VM_compressor_space_shortage(boolean_t);
void memorystatus_thread_wake(void);
extern uint32_t jetsam_kill_on_low_swap;
bool memorystatus_disable_swap(void);
#if CONFIG_PHANTOM_CACHE
extern bool memorystatus_phantom_cache_pressure;
#endif /* CONFIG_PHANTOM_CACHE */
int compressor_thrashing_induced_jetsam = 0;
int filecache_thrashing_induced_jetsam = 0;
static boolean_t vm_compressor_thrashing_detected = FALSE;
#else /* CONFIG_JETSAM */
static bool no_paging_space_action_in_progress = false;
extern void memorystatus_send_low_swap_note(void);
#endif /* CONFIG_JETSAM */
static void
vm_compressor_take_paging_space_action(void)
{
#if CONFIG_JETSAM
/*
* On systems with both swap and jetsam,
* just wake up the jetsam thread and have it handle the low swap condition
* by killing apps.
*/
if (jetsam_kill_on_low_swap) {
memorystatus_thread_wake();
}
#else /* CONFIG_JETSAM */
if (os_atomic_cmpxchg(&no_paging_space_action_in_progress, false, true, relaxed)) {
if (no_paging_space_action()) {
#if DEVELOPMENT || DEBUG
if (kill_on_no_paging_space) {
/*
* Since we are choosing to always kill a process, we don't need the
* "out of application memory" dialog box in this mode. And, hence we won't
* send the knote.
*/
os_atomic_store(&no_paging_space_action_in_progress, false, relaxed);
return;
}
#endif /* DEVELOPMENT || DEBUG */
memorystatus_send_low_swap_note();
}
os_atomic_store(&no_paging_space_action_in_progress, false, relaxed);
}
#endif /* !CONFIG_JETSAM */
}
void
vm_decompressor_lock(void)
{
PAGE_REPLACEMENT_ALLOWED(TRUE);
decompressions_blocked = TRUE;
PAGE_REPLACEMENT_ALLOWED(FALSE);
}
void
vm_decompressor_unlock(void)
{
PAGE_REPLACEMENT_ALLOWED(TRUE);
decompressions_blocked = FALSE;
PAGE_REPLACEMENT_ALLOWED(FALSE);
thread_wakeup((event_t)&decompressions_blocked);
}
static inline void
cslot_copy(c_slot_t cdst, c_slot_t csrc)
{
#if CHECKSUM_THE_DATA
cdst->c_hash_data = csrc->c_hash_data;
#endif
#if CHECKSUM_THE_COMPRESSED_DATA
cdst->c_hash_compressed_data = csrc->c_hash_compressed_data;
#endif
#if POPCOUNT_THE_COMPRESSED_DATA
cdst->c_pop_cdata = csrc->c_pop_cdata;
#endif
cdst->c_size = csrc->c_size;
cdst->c_packed_ptr = csrc->c_packed_ptr;
#if defined(__arm64__)
cdst->c_codec = csrc->c_codec;
#endif
}
#if XNU_TARGET_OS_OSX
#define VM_COMPRESSOR_MAX_POOL_SIZE (192UL << 30)
#else
#define VM_COMPRESSOR_MAX_POOL_SIZE (0)
#endif
static vm_map_size_t compressor_size;
static SECURITY_READ_ONLY_LATE(struct mach_vm_range) compressor_range;
vm_map_t compressor_map;
uint64_t compressor_pool_max_size;
uint64_t compressor_pool_size;
uint32_t compressor_pool_multiplier;
#if DEVELOPMENT || DEBUG
/*
* Compressor segments are write-protected in development/debug
* kernels to help debug memory corruption.
* In cases where performance is a concern, this can be disabled
* via the boot-arg "-disable_cseg_write_protection".
*/
boolean_t write_protect_c_segs = TRUE;
int vm_compressor_test_seg_wp;
uint32_t vm_ktrace_enabled;
#endif /* DEVELOPMENT || DEBUG */
#if (XNU_TARGET_OS_OSX && __arm64__)
#include <IOKit/IOPlatformExpert.h>
#include <sys/random.h>
static const char *csegbufsizeExperimentProperty = "_csegbufsz_experiment";
static thread_call_t csegbufsz_experiment_thread_call;
extern boolean_t IOServiceWaitForMatchingResource(const char * property, uint64_t timeout);
static void
erase_csegbufsz_experiment_property(__unused void *param0, __unused void *param1)
{
// Wait for NVRAM to be writable
if (!IOServiceWaitForMatchingResource("IONVRAM", UINT64_MAX)) {
printf("csegbufsz_experiment_property: Failed to wait for IONVRAM.");
}
if (!PERemoveNVRAMProperty(csegbufsizeExperimentProperty)) {
printf("csegbufsize_experiment_property: Failed to remove %s from NVRAM.", csegbufsizeExperimentProperty);
}
thread_call_free(csegbufsz_experiment_thread_call);
}
static void
erase_csegbufsz_experiment_property_async()
{
csegbufsz_experiment_thread_call = thread_call_allocate_with_priority(
erase_csegbufsz_experiment_property,
NULL,
THREAD_CALL_PRIORITY_LOW
);
if (csegbufsz_experiment_thread_call == NULL) {
printf("csegbufsize_experiment_property: Unable to allocate thread call.");
} else {
thread_call_enter(csegbufsz_experiment_thread_call);
}
}
static void
cleanup_csegbufsz_experiment(__unused void *arg0)
{
char nvram = 0;
unsigned int len = sizeof(nvram);
if (PEReadNVRAMProperty(csegbufsizeExperimentProperty, &nvram, &len)) {
erase_csegbufsz_experiment_property_async();
}
}
STARTUP_ARG(EARLY_BOOT, STARTUP_RANK_FIRST, cleanup_csegbufsz_experiment, NULL);
#endif /* XNU_TARGET_OS_OSX && __arm64__ */
#if CONFIG_JETSAM
extern unsigned int memorystatus_swap_all_apps;
#endif /* CONFIG_JETSAM */
TUNABLE_DT(uint64_t, swap_vol_min_capacity, "/defaults", "kern.swap_min_capacity", "kern.swap_min_capacity", 0, TUNABLE_DT_NONE);
static void
vm_compressor_set_size(void)
{
/*
* Note that this function may be called multiple times on systems with app swap
* because the value of vm_swap_get_max_configured_space() and memorystatus_swap_all_apps
* can change based the size of the swap volume. On these systems, we'll call
* this function once early in boot to reserve the maximum amount of VA required
* for the compressor submap and then one more time in vm_compressor_init after
* determining the swap volume size. We must not return a larger value the second
* time around.
*/
vm_size_t c_segments_arr_size = 0;
struct c_slot_mapping tmp_slot_ptr;
/* The segment size can be overwritten by a boot-arg */
if (!PE_parse_boot_argn("vm_compressor_segment_buffer_size", &c_seg_bufsize, sizeof(c_seg_bufsize))) {
#if CONFIG_JETSAM
if (memorystatus_swap_all_apps) {
c_seg_bufsize = C_SEG_BUFSIZE_ARM_SWAP;
} else {
c_seg_bufsize = C_SEG_BUFSIZE_DEFAULT;
}
#else
c_seg_bufsize = C_SEG_BUFSIZE_DEFAULT;
#endif /* CONFIG_JETSAM */
}
vm_compressor_swap_init_swap_file_limit();
if (vm_compression_limit) {
compressor_pool_size = ptoa_64(vm_compression_limit);
}
compressor_pool_max_size = C_SEG_MAX_LIMIT;
compressor_pool_max_size *= c_seg_bufsize;
#if XNU_TARGET_OS_OSX
if (vm_compression_limit == 0) {
if (max_mem <= (4ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_size = 16ULL * max_mem;
} else if (max_mem <= (8ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_size = 8ULL * max_mem;
} else if (max_mem <= (32ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_size = 4ULL * max_mem;
} else {
compressor_pool_size = 2ULL * max_mem;
}
}
/*
* Cap the compressor pool size to a max of 192G
*/
if (compressor_pool_size > VM_COMPRESSOR_MAX_POOL_SIZE) {
compressor_pool_size = VM_COMPRESSOR_MAX_POOL_SIZE;
}
if (max_mem <= (8ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_multiplier = 1;
} else if (max_mem <= (32ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_multiplier = 2;
} else {
compressor_pool_multiplier = 4;
}
#else
if (compressor_pool_max_size > max_mem) {
compressor_pool_max_size = max_mem;
}
if (vm_compression_limit == 0) {
compressor_pool_size = max_mem;
}
#if XNU_TARGET_OS_WATCH
compressor_pool_multiplier = 2;
#elif XNU_TARGET_OS_IOS
if (max_mem <= (2ULL * 1024ULL * 1024ULL * 1024ULL)) {
compressor_pool_multiplier = 2;
} else {
compressor_pool_multiplier = 1;
}
#else
compressor_pool_multiplier = 1;
#endif
#endif
PE_parse_boot_argn("kern.compressor_pool_multiplier", &compressor_pool_multiplier, sizeof(compressor_pool_multiplier));
if (compressor_pool_multiplier < 1) {
compressor_pool_multiplier = 1;
}
if (compressor_pool_size > compressor_pool_max_size) {
compressor_pool_size = compressor_pool_max_size;
}
c_seg_max_pages = (c_seg_bufsize / PAGE_SIZE);
c_seg_slot_var_array_min_len = c_seg_max_pages;
#if !defined(__x86_64__)
c_seg_off_limit = (C_SEG_BYTES_TO_OFFSET((c_seg_bufsize - 512)));
c_seg_allocsize = (c_seg_bufsize + PAGE_SIZE);
#else
c_seg_off_limit = (C_SEG_BYTES_TO_OFFSET((c_seg_bufsize - 128)));
c_seg_allocsize = c_seg_bufsize;
#endif /* !defined(__x86_64__) */
c_segments_limit = (uint32_t)(compressor_pool_size / (vm_size_t)(c_seg_allocsize));
tmp_slot_ptr.s_cseg = c_segments_limit;
/* Panic on internal configs*/
assertf((tmp_slot_ptr.s_cseg == c_segments_limit), "vm_compressor_init: overflowed s_cseg field in c_slot_mapping with c_segno: %d", c_segments_limit);
if (tmp_slot_ptr.s_cseg != c_segments_limit) {
tmp_slot_ptr.s_cseg = -1;
c_segments_limit = tmp_slot_ptr.s_cseg - 1; /*limited by segment idx bits in c_slot_mapping*/
compressor_pool_size = (c_segments_limit * (vm_size_t)(c_seg_allocsize));
}
c_segments_nearing_limit = (uint32_t)(((uint64_t)c_segments_limit * 98ULL) / 100ULL);
/* an upper limit on how many input pages the compressor can hold */
c_segment_pages_compressed_limit = (c_segments_limit * (c_seg_bufsize / PAGE_SIZE) * compressor_pool_multiplier);
if (c_segment_pages_compressed_limit < (uint32_t)(max_mem / PAGE_SIZE)) {
#if defined(XNU_TARGET_OS_WATCH)
c_segment_pages_compressed_limit = (uint32_t)(max_mem / PAGE_SIZE);
#else
if (!vm_compression_limit) {
c_segment_pages_compressed_limit = (uint32_t)(max_mem / PAGE_SIZE);
}
#endif
}
c_segment_pages_compressed_nearing_limit = (uint32_t)(((uint64_t)c_segment_pages_compressed_limit * 98ULL) / 100ULL);
#if CONFIG_FREEZE
/*
* Our in-core limits are based on the size of the compressor pool.
* The c_segments_nearing_limit is also based on the compressor pool
* size and calculated above.
*/
c_segments_incore_limit = c_segments_limit;
if (freezer_incore_cseg_acct) {
/*
* Add enough segments to track all frozen c_segs that can be stored in swap.
*/
c_segments_limit += (uint32_t)(vm_swap_get_max_configured_space() / (vm_size_t)(c_seg_allocsize));
tmp_slot_ptr.s_cseg = c_segments_limit;
/* Panic on internal configs*/
assertf((tmp_slot_ptr.s_cseg == c_segments_limit), "vm_compressor_init: freezer reserve overflowed s_cseg field in c_slot_mapping with c_segno: %d", c_segments_limit);
}
#endif
/*
* Submap needs space for:
* - c_segments
* - c_buffers
* - swap reclaimations -- c_seg_bufsize
*/
c_segments_arr_size = vm_map_round_page((sizeof(union c_segu) * c_segments_limit), VM_MAP_PAGE_MASK(kernel_map));
c_buffers_size = vm_map_round_page(((vm_size_t)c_seg_allocsize * (vm_size_t)c_segments_limit), VM_MAP_PAGE_MASK(kernel_map));
compressor_size = c_segments_arr_size + c_buffers_size + c_seg_bufsize;
#if RECORD_THE_COMPRESSED_DATA
c_compressed_record_sbuf_size = (vm_size_t)c_seg_allocsize + (PAGE_SIZE * 2);
compressor_size += c_compressed_record_sbuf_size;
#endif /* RECORD_THE_COMPRESSED_DATA */
}
STARTUP(KMEM, STARTUP_RANK_FIRST, vm_compressor_set_size);
KMEM_RANGE_REGISTER_DYNAMIC(compressor, &compressor_range, ^() {
return compressor_size;
});
bool
osenvironment_is_diagnostics(void)
{
DTEntry chosen;
const char *osenvironment;
unsigned int size;
if (kSuccess == SecureDTLookupEntry(0, "/chosen", &chosen)) {
if (kSuccess == SecureDTGetProperty(chosen, "osenvironment", (void const **) &osenvironment, &size)) {
return strcmp(osenvironment, "diagnostics") == 0;
}
}
return false;
}
void
vm_compressor_init(void)
{
thread_t thread;
#if RECORD_THE_COMPRESSED_DATA
vm_size_t c_compressed_record_sbuf_size = 0;
#endif /* RECORD_THE_COMPRESSED_DATA */
#if DEVELOPMENT || DEBUG || CONFIG_FREEZE
char bootarg_name[32];
#endif /* DEVELOPMENT || DEBUG || CONFIG_FREEZE */
__unused uint64_t early_boot_compressor_size = compressor_size;
#if CONFIG_JETSAM
if (memorystatus_swap_all_apps && osenvironment_is_diagnostics()) {
printf("osenvironment == \"diagnostics\". Disabling app swap.\n");
memorystatus_disable_swap();
}
if (memorystatus_swap_all_apps) {
/*
* App swap is disabled on devices with small NANDs.
* Now that we're no longer in early boot, we can get
* the NAND size and re-run vm_compressor_set_size.
*/
int error = vm_swap_vol_get_capacity(SWAP_VOLUME_NAME, &vm_swap_volume_capacity);
#if DEVELOPMENT || DEBUG
if (error != 0) {
panic("vm_compressor_init: Unable to get swap volume capacity. error=%d\n", error);
}
#else
if (error != 0) {
os_log_with_startup_serial(OS_LOG_DEFAULT, "vm_compressor_init: Unable to get swap volume capacity. error=%d\n", error);
}
#endif /* DEVELOPMENT || DEBUG */
if (vm_swap_volume_capacity < swap_vol_min_capacity) {
memorystatus_disable_swap();
}
/*
* Resize the compressor and swap now that we know the capacity
* of the swap volume.
*/
vm_compressor_set_size();
/*
* We reserved a chunk of VA early in boot for the compressor submap.
* We can't allocate more than that.
*/
assert(compressor_size <= early_boot_compressor_size);
}
#endif /* CONFIG_JETSAM */
#if DEVELOPMENT || DEBUG
if (PE_parse_boot_argn("-disable_cseg_write_protection", bootarg_name, sizeof(bootarg_name))) {
write_protect_c_segs = FALSE;
}
int vmcval = 1;
#if defined(XNU_TARGET_OS_WATCH)
vmcval = 0;
#endif /* XNU_TARGET_OS_WATCH */
PE_parse_boot_argn("vm_compressor_validation", &vmcval, sizeof(vmcval));
if (kern_feature_override(KF_COMPRSV_OVRD)) {
vmcval = 0;
}
if (vmcval == 0) {
#if POPCOUNT_THE_COMPRESSED_DATA
popcount_c_segs = FALSE;
#endif
#if CHECKSUM_THE_DATA || CHECKSUM_THE_COMPRESSED_DATA
checksum_c_segs = FALSE;
#endif
#if VALIDATE_C_SEGMENTS
validate_c_segs = FALSE;
#endif
write_protect_c_segs = FALSE;
}
#endif /* DEVELOPMENT || DEBUG */
#if CONFIG_FREEZE
if (PE_parse_boot_argn("-disable_freezer_cseg_acct", bootarg_name, sizeof(bootarg_name))) {
freezer_incore_cseg_acct = FALSE;
}
#endif /* CONFIG_FREEZE */
assert((C_SEGMENTS_PER_PAGE * sizeof(union c_segu)) == PAGE_SIZE);
#if !XNU_TARGET_OS_OSX
vm_compressor_minorcompact_threshold_divisor = 20;
vm_compressor_majorcompact_threshold_divisor = 30;
vm_compressor_unthrottle_threshold_divisor = 40;
vm_compressor_catchup_threshold_divisor = 60;
#else /* !XNU_TARGET_OS_OSX */
if (max_mem <= (3ULL * 1024ULL * 1024ULL * 1024ULL)) {
vm_compressor_minorcompact_threshold_divisor = 11;
vm_compressor_majorcompact_threshold_divisor = 13;
vm_compressor_unthrottle_threshold_divisor = 20;
vm_compressor_catchup_threshold_divisor = 35;
} else {
vm_compressor_minorcompact_threshold_divisor = 20;
vm_compressor_majorcompact_threshold_divisor = 25;
vm_compressor_unthrottle_threshold_divisor = 35;
vm_compressor_catchup_threshold_divisor = 50;
}
#endif /* !XNU_TARGET_OS_OSX */
queue_init(&c_bad_list_head);
queue_init(&c_age_list_head);
queue_init(&c_minor_list_head);
queue_init(&c_major_list_head);
queue_init(&c_filling_list_head);
queue_init(&c_early_swapout_list_head);
queue_init(&c_regular_swapout_list_head);
queue_init(&c_late_swapout_list_head);
queue_init(&c_swapio_list_head);
queue_init(&c_early_swappedin_list_head);
queue_init(&c_regular_swappedin_list_head);
queue_init(&c_late_swappedin_list_head);
queue_init(&c_swappedout_list_head);
queue_init(&c_swappedout_sparse_list_head);
c_free_segno_head = -1;
c_segments_available = 0;
compressor_map = kmem_suballoc(kernel_map, &compressor_range.min_address,
compressor_size, VM_MAP_CREATE_NEVER_FAULTS,
VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE, KMS_NOFAIL | KMS_PERMANENT,
VM_KERN_MEMORY_COMPRESSOR).kmr_submap;
kmem_alloc(compressor_map, (vm_offset_t *)(&c_segments),
(sizeof(union c_segu) * c_segments_limit),
KMA_NOFAIL | KMA_KOBJECT | KMA_VAONLY | KMA_PERMANENT,
VM_KERN_MEMORY_COMPRESSOR);
kmem_alloc(compressor_map, &c_buffers, c_buffers_size,
KMA_NOFAIL | KMA_COMPRESSOR | KMA_VAONLY | KMA_PERMANENT,
VM_KERN_MEMORY_COMPRESSOR);
#if DEVELOPMENT || DEBUG
if (hvg_is_hcall_available(HVG_HCALL_SET_COREDUMP_DATA)) {
hvg_hcall_set_coredump_data();
}
#endif
/*
* Pick a good size that will minimize fragmentation in zalloc
* by minimizing the fragmentation in a 16k run.
*
* c_seg_slot_var_array_min_len is larger on 4k systems than 16k ones,
* making the fragmentation in a 4k page terrible. Using 16k for all
* systems matches zalloc() and will minimize fragmentation.
*/
uint32_t c_segment_size = sizeof(struct c_segment) + (c_seg_slot_var_array_min_len * sizeof(struct c_slot));
uint32_t cnt = (16 << 10) / c_segment_size;
uint32_t frag = (16 << 10) % c_segment_size;
c_seg_fixed_array_len = c_seg_slot_var_array_min_len;
while (cnt * sizeof(struct c_slot) < frag) {
c_segment_size += sizeof(struct c_slot);
c_seg_fixed_array_len++;
frag -= cnt * sizeof(struct c_slot);
}
compressor_segment_zone = zone_create("compressor_segment",
c_segment_size, ZC_PGZ_USE_GUARDS | ZC_NOENCRYPT | ZC_ZFREE_CLEARMEM);
c_segments_busy = FALSE;
c_segments_next_page = (caddr_t)c_segments;
vm_compressor_algorithm_init();
{
host_basic_info_data_t hinfo;
mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
size_t bufsize;
char *buf;
#define BSD_HOST 1
host_info((host_t)BSD_HOST, HOST_BASIC_INFO, (host_info_t)&hinfo, &count);
compressor_cpus = hinfo.max_cpus;
/* allocate various scratch buffers at the same place */
bufsize = PAGE_SIZE;
bufsize += compressor_cpus * vm_compressor_get_decode_scratch_size();
/* For the panic path */
bufsize += vm_compressor_get_decode_scratch_size();
#if CONFIG_FREEZE
bufsize += vm_compressor_get_encode_scratch_size();
#endif
#if RECORD_THE_COMPRESSED_DATA
bufsize += c_compressed_record_sbuf_size;
#endif
kmem_alloc(kernel_map, (vm_offset_t *)&buf, bufsize,
KMA_DATA | KMA_NOFAIL | KMA_KOBJECT | KMA_PERMANENT,
VM_KERN_MEMORY_COMPRESSOR);
/*
* vm_compressor_kdp_state.kc_decompressed_page must be page aligned because we access
* it through the physical aperture by page number.
*/
vm_compressor_kdp_state.kc_panic_decompressed_page = buf;
vm_compressor_kdp_state.kc_panic_decompressed_page_paddr = kvtophys((vm_offset_t)vm_compressor_kdp_state.kc_panic_decompressed_page);
vm_compressor_kdp_state.kc_panic_decompressed_page_ppnum = (ppnum_t) atop(vm_compressor_kdp_state.kc_panic_decompressed_page_paddr);
buf += PAGE_SIZE;
bufsize -= PAGE_SIZE;
compressor_scratch_bufs = buf;
buf += compressor_cpus * vm_compressor_get_decode_scratch_size();
bufsize -= compressor_cpus * vm_compressor_get_decode_scratch_size();
vm_compressor_kdp_state.kc_panic_scratch_buf = buf;
buf += vm_compressor_get_decode_scratch_size();
bufsize -= vm_compressor_get_decode_scratch_size();
/* This is set up before each stackshot in vm_compressor_kdp_init */
vm_compressor_kdp_state.kc_scratch_bufs = NULL;
#if CONFIG_FREEZE
freezer_context_global.freezer_ctx_compressor_scratch_buf = buf;
buf += vm_compressor_get_encode_scratch_size();
bufsize -= vm_compressor_get_encode_scratch_size();
#endif
#if RECORD_THE_COMPRESSED_DATA
c_compressed_record_sbuf = buf;
c_compressed_record_cptr = buf;
c_compressed_record_ebuf = c_compressed_record_sbuf + c_compressed_record_sbuf_size;
buf += c_compressed_record_sbuf_size;
bufsize -= c_compressed_record_sbuf_size;
#endif
assert(bufsize == 0);
}
if (kernel_thread_start_priority((thread_continue_t)vm_compressor_swap_trigger_thread, NULL,
BASEPRI_VM, &thread) != KERN_SUCCESS) {
panic("vm_compressor_swap_trigger_thread: create failed");
}
thread_deallocate(thread);
if (vm_pageout_internal_start() != KERN_SUCCESS) {
panic("vm_compressor_init: Failed to start the internal pageout thread.");
}
if (VM_CONFIG_SWAP_IS_PRESENT) {
vm_compressor_swap_init();
}
if (VM_CONFIG_COMPRESSOR_IS_ACTIVE) {
vm_compressor_is_active = 1;
}
vm_compressor_available = 1;
vm_page_reactivate_all_throttled();
bzero(&vmcs_stats, sizeof(struct vm_compressor_swapper_stats));
}
#define COMPRESSOR_KDP_BUFSIZE (\
(vm_compressor_get_decode_scratch_size() * compressor_cpus) + \
(PAGE_SIZE * compressor_cpus)) + \
(sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_paddr) * compressor_cpus) + \
(sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_ppnum) * compressor_cpus)
/**
* Initializes the VM compressor in preparation for a stackshot.
* Stackshot mutex must be held.
*/
kern_return_t
vm_compressor_kdp_init(void)
{
char *buf;
kern_return_t err;
size_t bufsize;
size_t total_decode_size;
#if DEVELOPMENT || DEBUG
extern lck_mtx_t stackshot_subsys_mutex;
lck_mtx_assert(&stackshot_subsys_mutex, LCK_MTX_ASSERT_OWNED);
#endif /* DEVELOPMENT || DEBUG */
if (!vm_compressor_available) {
return KERN_SUCCESS;
}
bufsize = COMPRESSOR_KDP_BUFSIZE;
/* Allocate the per-cpu decompression pages. */
err = kmem_alloc(kernel_map, (vm_offset_t *)&buf, bufsize,
KMA_DATA | KMA_NOFAIL | KMA_KOBJECT,
VM_KERN_MEMORY_COMPRESSOR);
if (err != KERN_SUCCESS) {
return err;
}
assert(vm_compressor_kdp_state.kc_scratch_bufs == NULL);
vm_compressor_kdp_state.kc_scratch_bufs = buf;
total_decode_size = vm_compressor_get_decode_scratch_size() * compressor_cpus;
buf += total_decode_size;
bufsize -= total_decode_size;
/*
* vm_compressor_kdp_state.kc_decompressed_page must be page aligned because we access
* it through the physical aperture by page number.
*/
assert(vm_compressor_kdp_state.kc_decompressed_pages == NULL);
vm_compressor_kdp_state.kc_decompressed_pages = buf;
buf += PAGE_SIZE * compressor_cpus;
bufsize -= PAGE_SIZE * compressor_cpus;
/* Scary! This will be aligned, I promise :) */
assert(((vm_address_t) buf) % _Alignof(addr64_t) == 0);
assert(vm_compressor_kdp_state.kc_decompressed_pages_paddr == NULL);
vm_compressor_kdp_state.kc_decompressed_pages_paddr = (addr64_t*) (void*) buf;
buf += sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_paddr) * compressor_cpus;
bufsize -= sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_paddr) * compressor_cpus;
assert(((vm_address_t) buf) % _Alignof(ppnum_t) == 0);
assert(vm_compressor_kdp_state.kc_decompressed_pages_ppnum == NULL);
vm_compressor_kdp_state.kc_decompressed_pages_ppnum = (ppnum_t*) (void*) buf;
buf += sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_ppnum) * compressor_cpus;
bufsize -= sizeof(*vm_compressor_kdp_state.kc_decompressed_pages_ppnum) * compressor_cpus;
assert(bufsize == 0);
for (size_t i = 0; i < compressor_cpus; i++) {
vm_offset_t offset = (vm_offset_t) &vm_compressor_kdp_state.kc_decompressed_pages[i * PAGE_SIZE];
vm_compressor_kdp_state.kc_decompressed_pages_paddr[i] = kvtophys(offset);
vm_compressor_kdp_state.kc_decompressed_pages_ppnum[i] = (ppnum_t) atop(vm_compressor_kdp_state.kc_decompressed_pages_paddr[i]);
}
return KERN_SUCCESS;
}
/*
* Frees up compressor buffers used by stackshot.
* Stackshot mutex must be held.
*/
void
vm_compressor_kdp_teardown(void)
{
extern lck_mtx_t stackshot_subsys_mutex;
LCK_MTX_ASSERT(&stackshot_subsys_mutex, LCK_MTX_ASSERT_OWNED);
if (vm_compressor_kdp_state.kc_scratch_bufs == NULL) {
return;
}
/* Deallocate the per-cpu decompression pages. */
kmem_free(kernel_map, (vm_offset_t) vm_compressor_kdp_state.kc_scratch_bufs, COMPRESSOR_KDP_BUFSIZE);
vm_compressor_kdp_state.kc_scratch_bufs = NULL;
vm_compressor_kdp_state.kc_decompressed_pages = NULL;
vm_compressor_kdp_state.kc_decompressed_pages_paddr = 0;
vm_compressor_kdp_state.kc_decompressed_pages_ppnum = 0;
}
#if VALIDATE_C_SEGMENTS
static void
c_seg_validate(c_segment_t c_seg, boolean_t must_be_compact)
{
uint16_t c_indx;
int32_t bytes_used;
uint32_t c_rounded_size;
uint32_t c_size;
c_slot_t cs;
if (__probable(validate_c_segs == FALSE)) {
return;
}
if (c_seg->c_firstemptyslot < c_seg->c_nextslot) {
c_indx = c_seg->c_firstemptyslot;
cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
if (cs == NULL) {
panic("c_seg_validate: no slot backing c_firstemptyslot");
}
if (cs->c_size) {
panic("c_seg_validate: c_firstemptyslot has non-zero size (%d)", cs->c_size);
}
}
bytes_used = 0;
for (c_indx = 0; c_indx < c_seg->c_nextslot; c_indx++) {
cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
c_size = UNPACK_C_SIZE(cs);
c_rounded_size = (c_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
bytes_used += c_rounded_size;
#if CHECKSUM_THE_COMPRESSED_DATA
unsigned csvhash;
if (c_size && cs->c_hash_compressed_data != (csvhash = vmc_hash((char *)&c_seg->c_store.c_buffer[cs->c_offset], c_size))) {
addr64_t csvphys = kvtophys((vm_offset_t)&c_seg->c_store.c_buffer[cs->c_offset]);
panic("Compressed data doesn't match original %p phys: 0x%llx %d %p %d %d 0x%x 0x%x", c_seg, csvphys, cs->c_offset, cs, c_indx, c_size, cs->c_hash_compressed_data, csvhash);
}
#endif
#if POPCOUNT_THE_COMPRESSED_DATA
unsigned csvpop;
if (c_size) {
uintptr_t csvaddr = (uintptr_t) &c_seg->c_store.c_buffer[cs->c_offset];
if (cs->c_pop_cdata != (csvpop = vmc_pop(csvaddr, c_size))) {
panic("Compressed data popcount doesn't match original, bit distance: %d %p (phys: %p) %p %p 0x%llx 0x%x 0x%x 0x%x", (csvpop - cs->c_pop_cdata), (void *)csvaddr, (void *) kvtophys(csvaddr), c_seg, cs, (uint64_t)cs->c_offset, c_size, csvpop, cs->c_pop_cdata);
}
}
#endif
}
if (bytes_used != c_seg->c_bytes_used) {
panic("c_seg_validate: bytes_used mismatch - found %d, segment has %d", bytes_used, c_seg->c_bytes_used);
}
if (c_seg->c_bytes_used > C_SEG_OFFSET_TO_BYTES((int32_t)c_seg->c_nextoffset)) {
panic("c_seg_validate: c_bytes_used > c_nextoffset - c_nextoffset = %d, c_bytes_used = %d",
(int32_t)C_SEG_OFFSET_TO_BYTES((int32_t)c_seg->c_nextoffset), c_seg->c_bytes_used);
}
if (must_be_compact) {
if (c_seg->c_bytes_used != C_SEG_OFFSET_TO_BYTES((int32_t)c_seg->c_nextoffset)) {
panic("c_seg_validate: c_bytes_used doesn't match c_nextoffset - c_nextoffset = %d, c_bytes_used = %d",
(int32_t)C_SEG_OFFSET_TO_BYTES((int32_t)c_seg->c_nextoffset), c_seg->c_bytes_used);
}
}
}
#endif
void
c_seg_need_delayed_compaction(c_segment_t c_seg, boolean_t c_list_lock_held)
{
boolean_t clear_busy = FALSE;
if (c_list_lock_held == FALSE) {
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
C_SEG_BUSY(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
clear_busy = TRUE;
}
}
assert(c_seg->c_state != C_IS_FILLING);
if (!c_seg->c_on_minorcompact_q && !(C_SEG_IS_ON_DISK_OR_SOQ(c_seg)) && !c_seg->c_has_donated_pages) {
queue_enter(&c_minor_list_head, c_seg, c_segment_t, c_list);
c_seg->c_on_minorcompact_q = 1;
os_atomic_inc(&c_minor_count, relaxed);
}
if (c_list_lock_held == FALSE) {
lck_mtx_unlock_always(c_list_lock);
}
if (clear_busy == TRUE) {
C_SEG_WAKEUP_DONE(c_seg);
}
}
unsigned int c_seg_moved_to_sparse_list = 0;
void
c_seg_move_to_sparse_list(c_segment_t c_seg)
{
boolean_t clear_busy = FALSE;
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
C_SEG_BUSY(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
clear_busy = TRUE;
}
c_seg_switch_state(c_seg, C_ON_SWAPPEDOUTSPARSE_Q, FALSE);
c_seg_moved_to_sparse_list++;
lck_mtx_unlock_always(c_list_lock);
if (clear_busy == TRUE) {
C_SEG_WAKEUP_DONE(c_seg);
}
}
int try_minor_compaction_failed = 0;
int try_minor_compaction_succeeded = 0;
void
c_seg_try_minor_compaction_and_unlock(c_segment_t c_seg)
{
assert(c_seg->c_on_minorcompact_q);
/*
* c_seg is currently on the delayed minor compaction
* queue and we have c_seg locked... if we can get the
* c_list_lock w/o blocking (if we blocked we could deadlock
* because the lock order is c_list_lock then c_seg's lock)
* we'll pull it from the delayed list and free it directly
*/
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
/*
* c_list_lock is held, we need to bail
*/
try_minor_compaction_failed++;
lck_mtx_unlock_always(&c_seg->c_lock);
} else {
try_minor_compaction_succeeded++;
C_SEG_BUSY(c_seg);
c_seg_do_minor_compaction_and_unlock(c_seg, TRUE, FALSE, FALSE);
}
}
int
c_seg_do_minor_compaction_and_unlock(c_segment_t c_seg, boolean_t clear_busy, boolean_t need_list_lock, boolean_t disallow_page_replacement)
{
int c_seg_freed;
assert(c_seg->c_busy);
assert(!C_SEG_IS_ON_DISK_OR_SOQ(c_seg));
/*
* check for the case that can occur when we are not swapping
* and this segment has been major compacted in the past
* and moved to the majorcompact q to remove it from further
* consideration... if the occupancy falls too low we need
* to put it back on the age_q so that it will be considered
* in the next major compaction sweep... if we don't do this
* we will eventually run into the c_segments_limit
*/
if (c_seg->c_state == C_ON_MAJORCOMPACT_Q && C_SEG_SHOULD_MAJORCOMPACT_NOW(c_seg)) {
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
}
if (!c_seg->c_on_minorcompact_q) {
if (clear_busy == TRUE) {
C_SEG_WAKEUP_DONE(c_seg);
}
lck_mtx_unlock_always(&c_seg->c_lock);
return 0;
}
queue_remove(&c_minor_list_head, c_seg, c_segment_t, c_list);
c_seg->c_on_minorcompact_q = 0;
os_atomic_dec(&c_minor_count, relaxed);
lck_mtx_unlock_always(c_list_lock);
if (disallow_page_replacement == TRUE) {
lck_mtx_unlock_always(&c_seg->c_lock);
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
c_seg_freed = c_seg_minor_compaction_and_unlock(c_seg, clear_busy);
if (disallow_page_replacement == TRUE) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
if (need_list_lock == TRUE) {
lck_mtx_lock_spin_always(c_list_lock);
}
return c_seg_freed;
}
void
kdp_compressor_busy_find_owner(event64_t wait_event, thread_waitinfo_t *waitinfo)
{
c_segment_t c_seg = (c_segment_t) wait_event;
waitinfo->owner = thread_tid(c_seg->c_busy_for_thread);
waitinfo->context = VM_KERNEL_UNSLIDE_OR_PERM(c_seg);
}
#if DEVELOPMENT || DEBUG
int
do_cseg_wedge_thread(void)
{
struct c_segment c_seg;
c_seg.c_busy_for_thread = current_thread();
debug_cseg_wait_event = (event_t) &c_seg;
thread_set_pending_block_hint(current_thread(), kThreadWaitCompressor);
assert_wait((event_t) (&c_seg), THREAD_INTERRUPTIBLE);
thread_block(THREAD_CONTINUE_NULL);
return 0;
}
int
do_cseg_unwedge_thread(void)
{
thread_wakeup(debug_cseg_wait_event);
debug_cseg_wait_event = NULL;
return 0;
}
#endif /* DEVELOPMENT || DEBUG */
void
c_seg_wait_on_busy(c_segment_t c_seg)
{
c_seg->c_wanted = 1;
thread_set_pending_block_hint(current_thread(), kThreadWaitCompressor);
assert_wait((event_t) (c_seg), THREAD_UNINT);
lck_mtx_unlock_always(&c_seg->c_lock);
thread_block(THREAD_CONTINUE_NULL);
}
#if CONFIG_FREEZE
/*
* We don't have the task lock held while updating the task's
* c_seg queues. We can do that because of the following restrictions:
*
* - SINGLE FREEZER CONTEXT:
* We 'insert' c_segs into the task list on the task_freeze path.
* There can only be one such freeze in progress and the task
* isn't disappearing because we have the VM map lock held throughout
* and we have a reference on the proc too.
*
* - SINGLE TASK DISOWN CONTEXT:
* We 'disown' c_segs of a task ONLY from the task_terminate context. So
* we don't need the task lock but we need the c_list_lock and the
* compressor master lock (shared). We also hold the individual
* c_seg locks (exclusive).
*
* If we either:
* - can't get the c_seg lock on a try, then we start again because maybe
* the c_seg is part of a compaction and might get freed. So we can't trust
* that linkage and need to restart our queue traversal.
* - OR, we run into a busy c_seg (say being swapped in or free-ing) we
* drop all locks again and wait and restart our queue traversal.
*
* - The new_owner_task below is currently only the kernel or NULL.
*
*/
void
c_seg_update_task_owner(c_segment_t c_seg, task_t new_owner_task)
{
task_t owner_task = c_seg->c_task_owner;
uint64_t uncompressed_bytes = ((c_seg->c_slots_used) * PAGE_SIZE_64);
LCK_MTX_ASSERT(c_list_lock, LCK_MTX_ASSERT_OWNED);
LCK_MTX_ASSERT(&c_seg->c_lock, LCK_MTX_ASSERT_OWNED);
if (owner_task) {
task_update_frozen_to_swap_acct(owner_task, uncompressed_bytes, DEBIT_FROM_SWAP);
queue_remove(&owner_task->task_frozen_cseg_q, c_seg,
c_segment_t, c_task_list_next_cseg);
}
if (new_owner_task) {
queue_enter(&new_owner_task->task_frozen_cseg_q, c_seg,
c_segment_t, c_task_list_next_cseg);
task_update_frozen_to_swap_acct(new_owner_task, uncompressed_bytes, CREDIT_TO_SWAP);
}
c_seg->c_task_owner = new_owner_task;
}
void
task_disown_frozen_csegs(task_t owner_task)
{
c_segment_t c_seg = NULL, next_cseg = NULL;
again:
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(c_list_lock);
for (c_seg = (c_segment_t) queue_first(&owner_task->task_frozen_cseg_q);
!queue_end(&owner_task->task_frozen_cseg_q, (queue_entry_t) c_seg);
c_seg = next_cseg) {
next_cseg = (c_segment_t) queue_next(&c_seg->c_task_list_next_cseg);
if (!lck_mtx_try_lock_spin_always(&c_seg->c_lock)) {
lck_mtx_unlock(c_list_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
goto again;
}
if (c_seg->c_busy) {
lck_mtx_unlock(c_list_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
c_seg_wait_on_busy(c_seg);
goto again;
}
assert(c_seg->c_task_owner == owner_task);
c_seg_update_task_owner(c_seg, kernel_task);
lck_mtx_unlock_always(&c_seg->c_lock);
}
lck_mtx_unlock(c_list_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
#endif /* CONFIG_FREEZE */
void
c_seg_switch_state(c_segment_t c_seg, int new_state, boolean_t insert_head)
{
int old_state = c_seg->c_state;
queue_head_t *donate_swapout_list_head, *donate_swappedin_list_head;
uint32_t *donate_swapout_count, *donate_swappedin_count;
/*
* On macOS the donate queue is swapped first ie the c_early_swapout queue.
* On other swap-capable platforms, we want to swap those out last. So we
* use the c_late_swapout queue.
*/
#if XNU_TARGET_OS_OSX /* tag:DONATE */
#if (DEVELOPMENT || DEBUG)
if (new_state != C_IS_FILLING) {
LCK_MTX_ASSERT(&c_seg->c_lock, LCK_MTX_ASSERT_OWNED);
}
LCK_MTX_ASSERT(c_list_lock, LCK_MTX_ASSERT_OWNED);
#endif /* DEVELOPMENT || DEBUG */
donate_swapout_list_head = &c_early_swapout_list_head;
donate_swapout_count = &c_early_swapout_count;
donate_swappedin_list_head = &c_early_swappedin_list_head;
donate_swappedin_count = &c_early_swappedin_count;
#else /* XNU_TARGET_OS_OSX */
donate_swapout_list_head = &c_late_swapout_list_head;
donate_swapout_count = &c_late_swapout_count;
donate_swappedin_list_head = &c_late_swappedin_list_head;
donate_swappedin_count = &c_late_swappedin_count;
#endif /* XNU_TARGET_OS_OSX */
switch (old_state) {
case C_IS_EMPTY:
assert(new_state == C_IS_FILLING || new_state == C_IS_FREE);
c_empty_count--;
break;
case C_IS_FILLING:
assert(new_state == C_ON_AGE_Q || new_state == C_ON_SWAPOUT_Q);
queue_remove(&c_filling_list_head, c_seg, c_segment_t, c_age_list);
c_filling_count--;
break;
case C_ON_AGE_Q:
assert(new_state == C_ON_SWAPOUT_Q || new_state == C_ON_MAJORCOMPACT_Q ||
new_state == C_IS_FREE);
queue_remove(&c_age_list_head, c_seg, c_segment_t, c_age_list);
c_age_count--;
break;
case C_ON_SWAPPEDIN_Q:
if (c_seg->c_has_donated_pages) {
assert(new_state == C_ON_SWAPOUT_Q || new_state == C_IS_FREE);
queue_remove(donate_swappedin_list_head, c_seg, c_segment_t, c_age_list);
*donate_swappedin_count -= 1;
} else {
assert(new_state == C_ON_AGE_Q || new_state == C_IS_FREE);
#if CONFIG_FREEZE
assert(c_seg->c_has_freezer_pages);
queue_remove(&c_early_swappedin_list_head, c_seg, c_segment_t, c_age_list);
c_early_swappedin_count--;
#else /* CONFIG_FREEZE */
queue_remove(&c_regular_swappedin_list_head, c_seg, c_segment_t, c_age_list);
c_regular_swappedin_count--;
#endif /* CONFIG_FREEZE */
}
break;
case C_ON_SWAPOUT_Q:
assert(new_state == C_ON_AGE_Q || new_state == C_IS_FREE || new_state == C_IS_EMPTY || new_state == C_ON_SWAPIO_Q);
#if CONFIG_FREEZE
if (c_seg->c_has_freezer_pages) {
if (c_seg->c_task_owner && (new_state != C_ON_SWAPIO_Q)) {
c_seg_update_task_owner(c_seg, NULL);
}
queue_remove(&c_early_swapout_list_head, c_seg, c_segment_t, c_age_list);
c_early_swapout_count--;
} else
#endif /* CONFIG_FREEZE */
{
if (c_seg->c_has_donated_pages) {
queue_remove(donate_swapout_list_head, c_seg, c_segment_t, c_age_list);
*donate_swapout_count -= 1;
} else {
queue_remove(&c_regular_swapout_list_head, c_seg, c_segment_t, c_age_list);
c_regular_swapout_count--;
}
}
if (new_state == C_ON_AGE_Q) {
c_seg->c_has_donated_pages = 0;
}
thread_wakeup((event_t)&compaction_swapper_running);
break;
case C_ON_SWAPIO_Q:
#if CONFIG_FREEZE
if (c_seg->c_has_freezer_pages) {
assert(new_state == C_ON_SWAPPEDOUT_Q || new_state == C_ON_SWAPPEDOUTSPARSE_Q || new_state == C_ON_AGE_Q);
} else
#endif /* CONFIG_FREEZE */
{
if (c_seg->c_has_donated_pages) {
assert(new_state == C_ON_SWAPPEDOUT_Q || new_state == C_ON_SWAPPEDOUTSPARSE_Q || new_state == C_ON_SWAPPEDIN_Q);
} else {
assert(new_state == C_ON_SWAPPEDOUT_Q || new_state == C_ON_SWAPPEDOUTSPARSE_Q || new_state == C_ON_AGE_Q);
}
}
queue_remove(&c_swapio_list_head, c_seg, c_segment_t, c_age_list);
c_swapio_count--;
break;
case C_ON_SWAPPEDOUT_Q:
assert(new_state == C_ON_SWAPPEDIN_Q || new_state == C_ON_AGE_Q ||
new_state == C_ON_SWAPPEDOUTSPARSE_Q ||
new_state == C_ON_BAD_Q || new_state == C_IS_EMPTY || new_state == C_IS_FREE);
queue_remove(&c_swappedout_list_head, c_seg, c_segment_t, c_age_list);
c_swappedout_count--;
break;
case C_ON_SWAPPEDOUTSPARSE_Q:
assert(new_state == C_ON_SWAPPEDIN_Q || new_state == C_ON_AGE_Q ||
new_state == C_ON_BAD_Q || new_state == C_IS_EMPTY || new_state == C_IS_FREE);
queue_remove(&c_swappedout_sparse_list_head, c_seg, c_segment_t, c_age_list);
c_swappedout_sparse_count--;
break;
case C_ON_MAJORCOMPACT_Q:
assert(new_state == C_ON_AGE_Q || new_state == C_IS_FREE);
queue_remove(&c_major_list_head, c_seg, c_segment_t, c_age_list);
c_major_count--;
break;
case C_ON_BAD_Q:
assert(new_state == C_IS_FREE);
queue_remove(&c_bad_list_head, c_seg, c_segment_t, c_age_list);
c_bad_count--;
break;
default:
panic("c_seg %p has bad c_state = %d", c_seg, old_state);
}
switch (new_state) {
case C_IS_FREE:
assert(old_state != C_IS_FILLING);
break;
case C_IS_EMPTY:
assert(old_state == C_ON_SWAPOUT_Q || old_state == C_ON_SWAPPEDOUT_Q || old_state == C_ON_SWAPPEDOUTSPARSE_Q);
c_empty_count++;
break;
case C_IS_FILLING:
assert(old_state == C_IS_EMPTY);
queue_enter(&c_filling_list_head, c_seg, c_segment_t, c_age_list);
c_filling_count++;
break;
case C_ON_AGE_Q:
assert(old_state == C_IS_FILLING || old_state == C_ON_SWAPPEDIN_Q ||
old_state == C_ON_SWAPOUT_Q || old_state == C_ON_SWAPIO_Q ||
old_state == C_ON_MAJORCOMPACT_Q || old_state == C_ON_SWAPPEDOUT_Q || old_state == C_ON_SWAPPEDOUTSPARSE_Q);
assert(!c_seg->c_has_donated_pages);
if (old_state == C_IS_FILLING) {
queue_enter(&c_age_list_head, c_seg, c_segment_t, c_age_list);
} else {
if (!queue_empty(&c_age_list_head)) {
c_segment_t c_first;
c_first = (c_segment_t)queue_first(&c_age_list_head);
c_seg->c_creation_ts = c_first->c_creation_ts;
}
queue_enter_first(&c_age_list_head, c_seg, c_segment_t, c_age_list);
}
c_age_count++;
break;
case C_ON_SWAPPEDIN_Q:
{
queue_head_t *list_head;
assert(old_state == C_ON_SWAPPEDOUT_Q || old_state == C_ON_SWAPPEDOUTSPARSE_Q || old_state == C_ON_SWAPIO_Q);
if (c_seg->c_has_donated_pages) {
/* Error in swapouts could happen while the c_seg is still on the swapio queue */
list_head = donate_swappedin_list_head;
*donate_swappedin_count += 1;
} else {
#if CONFIG_FREEZE
assert(c_seg->c_has_freezer_pages);
list_head = &c_early_swappedin_list_head;
c_early_swappedin_count++;
#else /* CONFIG_FREEZE */
list_head = &c_regular_swappedin_list_head;
c_regular_swappedin_count++;
#endif /* CONFIG_FREEZE */
}
if (insert_head == TRUE) {
queue_enter_first(list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(list_head, c_seg, c_segment_t, c_age_list);
}
break;
}
case C_ON_SWAPOUT_Q:
{
queue_head_t *list_head;
#if CONFIG_FREEZE
/*
* A segment with both identities of frozen + donated pages
* will be put on early swapout Q ie the frozen identity wins.
* This is because when both identities are set, the donation bit
* is added on after in the c_current_seg_filled path for accounting
* purposes.
*/
if (c_seg->c_has_freezer_pages) {
assert(old_state == C_ON_AGE_Q || old_state == C_IS_FILLING);
list_head = &c_early_swapout_list_head;
c_early_swapout_count++;
} else
#endif
{
if (c_seg->c_has_donated_pages) {
assert(old_state == C_ON_SWAPPEDIN_Q || old_state == C_IS_FILLING);
list_head = donate_swapout_list_head;
*donate_swapout_count += 1;
} else {
assert(old_state == C_ON_AGE_Q || old_state == C_IS_FILLING);
list_head = &c_regular_swapout_list_head;
c_regular_swapout_count++;
}
}
if (insert_head == TRUE) {
queue_enter_first(list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(list_head, c_seg, c_segment_t, c_age_list);
}
break;
}
case C_ON_SWAPIO_Q:
assert(old_state == C_ON_SWAPOUT_Q);
if (insert_head == TRUE) {
queue_enter_first(&c_swapio_list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(&c_swapio_list_head, c_seg, c_segment_t, c_age_list);
}
c_swapio_count++;
break;
case C_ON_SWAPPEDOUT_Q:
assert(old_state == C_ON_SWAPIO_Q);
if (insert_head == TRUE) {
queue_enter_first(&c_swappedout_list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(&c_swappedout_list_head, c_seg, c_segment_t, c_age_list);
}
c_swappedout_count++;
break;
case C_ON_SWAPPEDOUTSPARSE_Q:
assert(old_state == C_ON_SWAPIO_Q || old_state == C_ON_SWAPPEDOUT_Q);
if (insert_head == TRUE) {
queue_enter_first(&c_swappedout_sparse_list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(&c_swappedout_sparse_list_head, c_seg, c_segment_t, c_age_list);
}
c_swappedout_sparse_count++;
break;
case C_ON_MAJORCOMPACT_Q:
assert(old_state == C_ON_AGE_Q);
assert(!c_seg->c_has_donated_pages);
if (insert_head == TRUE) {
queue_enter_first(&c_major_list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(&c_major_list_head, c_seg, c_segment_t, c_age_list);
}
c_major_count++;
break;
case C_ON_BAD_Q:
assert(old_state == C_ON_SWAPPEDOUT_Q || old_state == C_ON_SWAPPEDOUTSPARSE_Q);
if (insert_head == TRUE) {
queue_enter_first(&c_bad_list_head, c_seg, c_segment_t, c_age_list);
} else {
queue_enter(&c_bad_list_head, c_seg, c_segment_t, c_age_list);
}
c_bad_count++;
break;
default:
panic("c_seg %p requesting bad c_state = %d", c_seg, new_state);
}
c_seg->c_state = new_state;
}
void
c_seg_free(c_segment_t c_seg)
{
assert(c_seg->c_busy);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_seg_free_locked(c_seg);
}
void
c_seg_free_locked(c_segment_t c_seg)
{
int segno;
int pages_populated = 0;
int32_t *c_buffer = NULL;
uint64_t c_swap_handle = 0;
assert(c_seg->c_busy);
assert(c_seg->c_slots_used == 0);
assert(!c_seg->c_on_minorcompact_q);
assert(!c_seg->c_busy_swapping);
if (c_seg->c_overage_swap == TRUE) {
c_overage_swapped_count--;
c_seg->c_overage_swap = FALSE;
}
if (!(C_SEG_IS_ONDISK(c_seg))) {
c_buffer = c_seg->c_store.c_buffer;
} else {
c_swap_handle = c_seg->c_store.c_swap_handle;
}
c_seg_switch_state(c_seg, C_IS_FREE, FALSE);
if (c_buffer) {
pages_populated = (round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset))) / PAGE_SIZE;
c_seg->c_store.c_buffer = NULL;
} else {
#if CONFIG_FREEZE
c_seg_update_task_owner(c_seg, NULL);
#endif /* CONFIG_FREEZE */
c_seg->c_store.c_swap_handle = (uint64_t)-1;
}
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_unlock_always(c_list_lock);
if (c_buffer) {
if (pages_populated) {
kernel_memory_depopulate((vm_offset_t)c_buffer,
ptoa(pages_populated), KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
}
} else if (c_swap_handle) {
/*
* Free swap space on disk.
*/
vm_swap_free(c_swap_handle);
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
/*
* c_seg must remain busy until
* after the call to vm_swap_free
*/
C_SEG_WAKEUP_DONE(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
segno = c_seg->c_mysegno;
lck_mtx_lock_spin_always(c_list_lock);
/*
* because the c_buffer is now associated with the segno,
* we can't put the segno back on the free list until
* after we have depopulated the c_buffer range, or
* we run the risk of depopulating a range that is
* now being used in one of the compressor heads
*/
c_segments[segno].c_segno = c_free_segno_head;
c_free_segno_head = segno;
c_segment_count--;
lck_mtx_unlock_always(c_list_lock);
lck_mtx_destroy(&c_seg->c_lock, &vm_compressor_lck_grp);
if (c_seg->c_slot_var_array_len) {
kfree_type(struct c_slot, c_seg->c_slot_var_array_len,
c_seg->c_slot_var_array);
}
zfree(compressor_segment_zone, c_seg);
}
#if DEVELOPMENT || DEBUG
int c_seg_trim_page_count = 0;
#endif
void
c_seg_trim_tail(c_segment_t c_seg)
{
c_slot_t cs;
uint32_t c_size;
uint32_t c_offset;
uint32_t c_rounded_size;
uint16_t current_nextslot;
uint32_t current_populated_offset;
if (c_seg->c_bytes_used == 0) {
return;
}
current_nextslot = c_seg->c_nextslot;
current_populated_offset = c_seg->c_populated_offset;
while (c_seg->c_nextslot) {
cs = C_SEG_SLOT_FROM_INDEX(c_seg, (c_seg->c_nextslot - 1));
c_size = UNPACK_C_SIZE(cs);
if (c_size) {
if (current_nextslot != c_seg->c_nextslot) {
c_rounded_size = (c_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
c_offset = cs->c_offset + C_SEG_BYTES_TO_OFFSET(c_rounded_size);
c_seg->c_nextoffset = c_offset;
c_seg->c_populated_offset = (c_offset + (C_SEG_BYTES_TO_OFFSET(PAGE_SIZE) - 1)) &
~(C_SEG_BYTES_TO_OFFSET(PAGE_SIZE) - 1);
if (c_seg->c_firstemptyslot > c_seg->c_nextslot) {
c_seg->c_firstemptyslot = c_seg->c_nextslot;
}
#if DEVELOPMENT || DEBUG
c_seg_trim_page_count += ((round_page_32(C_SEG_OFFSET_TO_BYTES(current_populated_offset)) -
round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset))) /
PAGE_SIZE);
#endif
}
break;
}
c_seg->c_nextslot--;
}
assert(c_seg->c_nextslot);
}
int
c_seg_minor_compaction_and_unlock(c_segment_t c_seg, boolean_t clear_busy)
{
c_slot_mapping_t slot_ptr;
uint32_t c_offset = 0;
uint32_t old_populated_offset;
uint32_t c_rounded_size;
uint32_t c_size;
uint16_t c_indx = 0;
int i;
c_slot_t c_dst;
c_slot_t c_src;
assert(c_seg->c_busy);
#if VALIDATE_C_SEGMENTS
c_seg_validate(c_seg, FALSE);
#endif
if (c_seg->c_bytes_used == 0) {
c_seg_free(c_seg);
return 1;
}
lck_mtx_unlock_always(&c_seg->c_lock);
if (c_seg->c_firstemptyslot >= c_seg->c_nextslot || C_SEG_UNUSED_BYTES(c_seg) < PAGE_SIZE) {
goto done;
}
/* TODO: assert first emptyslot's c_size is actually 0 */
#if DEVELOPMENT || DEBUG
C_SEG_MAKE_WRITEABLE(c_seg);
#endif
#if VALIDATE_C_SEGMENTS
c_seg->c_was_minor_compacted++;
#endif
c_indx = c_seg->c_firstemptyslot;
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
old_populated_offset = c_seg->c_populated_offset;
c_offset = c_dst->c_offset;
for (i = c_indx + 1; i < c_seg->c_nextslot && c_offset < c_seg->c_nextoffset; i++) {
c_src = C_SEG_SLOT_FROM_INDEX(c_seg, i);
c_size = UNPACK_C_SIZE(c_src);
if (c_size == 0) {
continue;
}
c_rounded_size = (c_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
/* N.B.: This memcpy may be an overlapping copy */
memcpy(&c_seg->c_store.c_buffer[c_offset], &c_seg->c_store.c_buffer[c_src->c_offset], c_rounded_size);
cslot_copy(c_dst, c_src);
c_dst->c_offset = c_offset;
slot_ptr = C_SLOT_UNPACK_PTR(c_dst);
slot_ptr->s_cindx = c_indx;
c_offset += C_SEG_BYTES_TO_OFFSET(c_rounded_size);
PACK_C_SIZE(c_src, 0);
c_indx++;
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
}
c_seg->c_firstemptyslot = c_indx;
c_seg->c_nextslot = c_indx;
c_seg->c_nextoffset = c_offset;
c_seg->c_populated_offset = (c_offset + (C_SEG_BYTES_TO_OFFSET(PAGE_SIZE) - 1)) & ~(C_SEG_BYTES_TO_OFFSET(PAGE_SIZE) - 1);
c_seg->c_bytes_unused = 0;
#if VALIDATE_C_SEGMENTS
c_seg_validate(c_seg, TRUE);
#endif
if (old_populated_offset > c_seg->c_populated_offset) {
uint32_t gc_size;
int32_t *gc_ptr;
gc_size = C_SEG_OFFSET_TO_BYTES(old_populated_offset - c_seg->c_populated_offset);
gc_ptr = &c_seg->c_store.c_buffer[c_seg->c_populated_offset];
kernel_memory_depopulate((vm_offset_t)gc_ptr, gc_size,
KMA_COMPRESSOR, VM_KERN_MEMORY_COMPRESSOR);
}
#if DEVELOPMENT || DEBUG
C_SEG_WRITE_PROTECT(c_seg);
#endif
done:
if (clear_busy == TRUE) {
lck_mtx_lock_spin_always(&c_seg->c_lock);
C_SEG_WAKEUP_DONE(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
}
return 0;
}
static void
c_seg_alloc_nextslot(c_segment_t c_seg)
{
struct c_slot *old_slot_array = NULL;
struct c_slot *new_slot_array = NULL;
int newlen;
int oldlen;
if (c_seg->c_nextslot < c_seg_fixed_array_len) {
return;
}
if ((c_seg->c_nextslot - c_seg_fixed_array_len) >= c_seg->c_slot_var_array_len) {
oldlen = c_seg->c_slot_var_array_len;
old_slot_array = c_seg->c_slot_var_array;
if (oldlen == 0) {
newlen = c_seg_slot_var_array_min_len;
} else {
newlen = oldlen * 2;
}
new_slot_array = kalloc_type(struct c_slot, newlen, Z_WAITOK);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (old_slot_array) {
memcpy(new_slot_array, old_slot_array,
sizeof(struct c_slot) * oldlen);
}
c_seg->c_slot_var_array_len = newlen;
c_seg->c_slot_var_array = new_slot_array;
lck_mtx_unlock_always(&c_seg->c_lock);
kfree_type(struct c_slot, oldlen, old_slot_array);
}
}
#define C_SEG_MAJOR_COMPACT_STATS_MAX (30)
struct {
uint64_t asked_permission;
uint64_t compactions;
uint64_t moved_slots;
uint64_t moved_bytes;
uint64_t wasted_space_in_swapouts;
uint64_t count_of_swapouts;
uint64_t count_of_freed_segs;
uint64_t bailed_compactions;
uint64_t bytes_freed_rate_us;
} c_seg_major_compact_stats[C_SEG_MAJOR_COMPACT_STATS_MAX];
int c_seg_major_compact_stats_now = 0;
#define C_MAJOR_COMPACTION_SIZE_APPROPRIATE ((c_seg_bufsize * 90) / 100)
boolean_t
c_seg_major_compact_ok(
c_segment_t c_seg_dst,
c_segment_t c_seg_src)
{
c_seg_major_compact_stats[c_seg_major_compact_stats_now].asked_permission++;
if (c_seg_src->c_bytes_used >= C_MAJOR_COMPACTION_SIZE_APPROPRIATE &&
c_seg_dst->c_bytes_used >= C_MAJOR_COMPACTION_SIZE_APPROPRIATE) {
return FALSE;
}
if (c_seg_dst->c_nextoffset >= c_seg_off_limit || c_seg_dst->c_nextslot >= C_SLOT_MAX_INDEX) {
/*
* destination segment is full... can't compact
*/
return FALSE;
}
return TRUE;
}
boolean_t
c_seg_major_compact(
c_segment_t c_seg_dst,
c_segment_t c_seg_src)
{
c_slot_mapping_t slot_ptr;
uint32_t c_rounded_size;
uint32_t c_size;
uint16_t dst_slot;
int i;
c_slot_t c_dst;
c_slot_t c_src;
boolean_t keep_compacting = TRUE;
/*
* segments are not locked but they are both marked c_busy
* which keeps c_decompress from working on them...
* we can safely allocate new pages, move compressed data
* from c_seg_src to c_seg_dst and update both c_segment's
* state w/o holding the master lock
*/
#if DEVELOPMENT || DEBUG
C_SEG_MAKE_WRITEABLE(c_seg_dst);
#endif
#if VALIDATE_C_SEGMENTS
c_seg_dst->c_was_major_compacted++;
c_seg_src->c_was_major_donor++;
#endif
assertf(c_seg_dst->c_has_donated_pages == c_seg_src->c_has_donated_pages, "Mismatched donation status Dst: %p, Src: %p\n", c_seg_dst, c_seg_src);
c_seg_major_compact_stats[c_seg_major_compact_stats_now].compactions++;
dst_slot = c_seg_dst->c_nextslot;
for (i = 0; i < c_seg_src->c_nextslot; i++) {
c_src = C_SEG_SLOT_FROM_INDEX(c_seg_src, i);
c_size = UNPACK_C_SIZE(c_src);
if (c_size == 0) {
/* BATCH: move what we have so far; */
continue;
}
int combined_size;
combined_size = c_size;
c_rounded_size = (combined_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
if (C_SEG_OFFSET_TO_BYTES(c_seg_dst->c_populated_offset - c_seg_dst->c_nextoffset) < (unsigned) combined_size) {
int size_to_populate;
/* doesn't fit */
size_to_populate = c_seg_bufsize - C_SEG_OFFSET_TO_BYTES(c_seg_dst->c_populated_offset);
if (size_to_populate == 0) {
/* can't fit */
keep_compacting = FALSE;
break;
}
if (size_to_populate > C_SEG_MAX_POPULATE_SIZE) {
size_to_populate = C_SEG_MAX_POPULATE_SIZE;
}
kernel_memory_populate(
(vm_offset_t) &c_seg_dst->c_store.c_buffer[c_seg_dst->c_populated_offset],
size_to_populate,
KMA_NOFAIL | KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
c_seg_dst->c_populated_offset += C_SEG_BYTES_TO_OFFSET(size_to_populate);
assert(C_SEG_OFFSET_TO_BYTES(c_seg_dst->c_populated_offset) <= c_seg_bufsize);
}
c_seg_alloc_nextslot(c_seg_dst);
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg_dst, c_seg_dst->c_nextslot);
memcpy(&c_seg_dst->c_store.c_buffer[c_seg_dst->c_nextoffset], &c_seg_src->c_store.c_buffer[c_src->c_offset], combined_size);
c_seg_major_compact_stats[c_seg_major_compact_stats_now].moved_slots++;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].moved_bytes += combined_size;
cslot_copy(c_dst, c_src);
c_dst->c_offset = c_seg_dst->c_nextoffset;
if (c_seg_dst->c_firstemptyslot == c_seg_dst->c_nextslot) {
c_seg_dst->c_firstemptyslot++;
}
c_seg_dst->c_slots_used++;
c_seg_dst->c_nextslot++;
c_seg_dst->c_bytes_used += c_rounded_size;
c_seg_dst->c_nextoffset += C_SEG_BYTES_TO_OFFSET(c_rounded_size);
PACK_C_SIZE(c_src, 0);
c_seg_src->c_bytes_used -= c_rounded_size;
c_seg_src->c_bytes_unused += c_rounded_size;
c_seg_src->c_firstemptyslot = 0;
assert(c_seg_src->c_slots_used);
c_seg_src->c_slots_used--;
if (!c_seg_src->c_swappedin) {
/* Pessimistically lose swappedin status when non-swappedin pages are added. */
c_seg_dst->c_swappedin = false;
}
if (c_seg_dst->c_nextoffset >= c_seg_off_limit || c_seg_dst->c_nextslot >= C_SLOT_MAX_INDEX) {
/* dest segment is now full */
keep_compacting = FALSE;
break;
}
}
#if DEVELOPMENT || DEBUG
C_SEG_WRITE_PROTECT(c_seg_dst);
#endif
if (dst_slot < c_seg_dst->c_nextslot) {
PAGE_REPLACEMENT_ALLOWED(TRUE);
/*
* we've now locked out c_decompress from
* converting the slot passed into it into
* a c_segment_t which allows us to use
* the backptr to change which c_segment and
* index the slot points to
*/
while (dst_slot < c_seg_dst->c_nextslot) {
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg_dst, dst_slot);
slot_ptr = C_SLOT_UNPACK_PTR(c_dst);
/* <csegno=0,indx=0> would mean "empty slot", so use csegno+1 */
slot_ptr->s_cseg = c_seg_dst->c_mysegno + 1;
slot_ptr->s_cindx = dst_slot++;
}
PAGE_REPLACEMENT_ALLOWED(FALSE);
}
return keep_compacting;
}
uint64_t
vm_compressor_compute_elapsed_msecs(clock_sec_t end_sec, clock_nsec_t end_nsec, clock_sec_t start_sec, clock_nsec_t start_nsec)
{
uint64_t end_msecs;
uint64_t start_msecs;
end_msecs = (end_sec * 1000) + end_nsec / 1000000;
start_msecs = (start_sec * 1000) + start_nsec / 1000000;
return end_msecs - start_msecs;
}
uint32_t compressor_eval_period_in_msecs = 250;
uint32_t compressor_sample_min_in_msecs = 500;
uint32_t compressor_sample_max_in_msecs = 10000;
uint32_t compressor_thrashing_threshold_per_10msecs = 50;
uint32_t compressor_thrashing_min_per_10msecs = 20;
/* When true, reset sample data next chance we get. */
static boolean_t compressor_need_sample_reset = FALSE;
void
compute_swapout_target_age(void)
{
clock_sec_t cur_ts_sec;
clock_nsec_t cur_ts_nsec;
uint32_t min_operations_needed_in_this_sample;
uint64_t elapsed_msecs_in_eval;
uint64_t elapsed_msecs_in_sample;
boolean_t need_eval_reset = FALSE;
clock_get_system_nanotime(&cur_ts_sec, &cur_ts_nsec);
elapsed_msecs_in_sample = vm_compressor_compute_elapsed_msecs(cur_ts_sec, cur_ts_nsec, start_of_sample_period_sec, start_of_sample_period_nsec);
if (compressor_need_sample_reset ||
elapsed_msecs_in_sample >= compressor_sample_max_in_msecs) {
compressor_need_sample_reset = TRUE;
need_eval_reset = TRUE;
goto done;
}
elapsed_msecs_in_eval = vm_compressor_compute_elapsed_msecs(cur_ts_sec, cur_ts_nsec, start_of_eval_period_sec, start_of_eval_period_nsec);
if (elapsed_msecs_in_eval < compressor_eval_period_in_msecs) {
goto done;
}
need_eval_reset = TRUE;
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_START, elapsed_msecs_in_eval, sample_period_compression_count, sample_period_decompression_count, 0, 0);
min_operations_needed_in_this_sample = (compressor_thrashing_min_per_10msecs * (uint32_t)elapsed_msecs_in_eval) / 10;
if ((sample_period_compression_count - last_eval_compression_count) < min_operations_needed_in_this_sample ||
(sample_period_decompression_count - last_eval_decompression_count) < min_operations_needed_in_this_sample) {
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, sample_period_compression_count - last_eval_compression_count,
sample_period_decompression_count - last_eval_decompression_count, 0, 1, 0);
swapout_target_age = 0;
compressor_need_sample_reset = TRUE;
need_eval_reset = TRUE;
goto done;
}
last_eval_compression_count = sample_period_compression_count;
last_eval_decompression_count = sample_period_decompression_count;
if (elapsed_msecs_in_sample < compressor_sample_min_in_msecs) {
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, swapout_target_age, 0, 0, 5, 0);
goto done;
}
if (sample_period_decompression_count > ((compressor_thrashing_threshold_per_10msecs * elapsed_msecs_in_sample) / 10)) {
uint64_t running_total;
uint64_t working_target;
uint64_t aging_target;
uint32_t oldest_age_of_csegs_sampled = 0;
uint64_t working_set_approximation = 0;
swapout_target_age = 0;
working_target = (sample_period_decompression_count / 100) * 95; /* 95 percent */
aging_target = (sample_period_decompression_count / 100) * 1; /* 1 percent */
running_total = 0;
for (oldest_age_of_csegs_sampled = 0; oldest_age_of_csegs_sampled < DECOMPRESSION_SAMPLE_MAX_AGE; oldest_age_of_csegs_sampled++) {
running_total += age_of_decompressions_during_sample_period[oldest_age_of_csegs_sampled];
working_set_approximation += oldest_age_of_csegs_sampled * age_of_decompressions_during_sample_period[oldest_age_of_csegs_sampled];
if (running_total >= working_target) {
break;
}
}
if (oldest_age_of_csegs_sampled < DECOMPRESSION_SAMPLE_MAX_AGE) {
working_set_approximation = (working_set_approximation * 1000) / elapsed_msecs_in_sample;
if (working_set_approximation < VM_PAGE_COMPRESSOR_COUNT) {
running_total = overage_decompressions_during_sample_period;
for (oldest_age_of_csegs_sampled = DECOMPRESSION_SAMPLE_MAX_AGE - 1; oldest_age_of_csegs_sampled; oldest_age_of_csegs_sampled--) {
running_total += age_of_decompressions_during_sample_period[oldest_age_of_csegs_sampled];
if (running_total >= aging_target) {
break;
}
}
swapout_target_age = (uint32_t)cur_ts_sec - oldest_age_of_csegs_sampled;
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, swapout_target_age, working_set_approximation, VM_PAGE_COMPRESSOR_COUNT, 2, 0);
} else {
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, working_set_approximation, VM_PAGE_COMPRESSOR_COUNT, 0, 3, 0);
}
} else {
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, working_target, running_total, 0, 4, 0);
}
compressor_need_sample_reset = TRUE;
need_eval_reset = TRUE;
} else {
KERNEL_DEBUG(0xe0400020 | DBG_FUNC_END, sample_period_decompression_count, (compressor_thrashing_threshold_per_10msecs * elapsed_msecs_in_sample) / 10, 0, 6, 0);
}
done:
if (compressor_need_sample_reset == TRUE) {
bzero(age_of_decompressions_during_sample_period, sizeof(age_of_decompressions_during_sample_period));
overage_decompressions_during_sample_period = 0;
start_of_sample_period_sec = cur_ts_sec;
start_of_sample_period_nsec = cur_ts_nsec;
sample_period_decompression_count = 0;
sample_period_compression_count = 0;
last_eval_decompression_count = 0;
last_eval_compression_count = 0;
compressor_need_sample_reset = FALSE;
}
if (need_eval_reset == TRUE) {
start_of_eval_period_sec = cur_ts_sec;
start_of_eval_period_nsec = cur_ts_nsec;
}
}
int compaction_swapper_init_now = 0;
int compaction_swapper_running = 0;
int compaction_swapper_awakened = 0;
int compaction_swapper_abort = 0;
bool
vm_compressor_swapout_is_ripe()
{
bool is_ripe = false;
if (vm_swapout_ripe_segments == TRUE && c_overage_swapped_count < c_overage_swapped_limit) {
c_segment_t c_seg;
clock_sec_t now;
clock_sec_t age;
clock_nsec_t nsec;
clock_get_system_nanotime(&now, &nsec);
age = 0;
lck_mtx_lock_spin_always(c_list_lock);
if (!queue_empty(&c_age_list_head)) {
c_seg = (c_segment_t) queue_first(&c_age_list_head);
age = now - c_seg->c_creation_ts;
}
lck_mtx_unlock_always(c_list_lock);
if (age >= vm_ripe_target_age) {
is_ripe = true;
}
}
return is_ripe;
}
static bool
compressor_swapout_conditions_met(void)
{
bool should_swap = false;
if (COMPRESSOR_NEEDS_TO_SWAP()) {
should_swap = true;
vmcs_stats.compressor_swap_threshold_exceeded++;
}
if (VM_PAGE_Q_THROTTLED(&vm_pageout_queue_external) && vm_page_anonymous_count < (vm_page_inactive_count / 20)) {
should_swap = true;
vmcs_stats.external_q_throttled++;
}
if (vm_page_free_count < (vm_page_free_reserved - (COMPRESSOR_FREE_RESERVED_LIMIT * 2))) {
should_swap = true;
vmcs_stats.free_count_below_reserve++;
}
return should_swap;
}
static bool
compressor_needs_to_swap()
{
bool should_swap = false;
if (vm_compressor_swapout_is_ripe()) {
should_swap = true;
goto check_if_low_space;
}
if (VM_CONFIG_SWAP_IS_ACTIVE) {
should_swap = compressor_swapout_conditions_met();
if (should_swap) {
goto check_if_low_space;
}
}
#if (XNU_TARGET_OS_OSX && __arm64__)
/*
* Thrashing detection disabled.
*/
#else /* (XNU_TARGET_OS_OSX && __arm64__) */
if (vm_compressor_is_thrashing()) {
should_swap = true;
vmcs_stats.thrashing_detected++;
}
#if CONFIG_PHANTOM_CACHE
if (vm_phantom_cache_check_pressure()) {
os_atomic_store(&memorystatus_phantom_cache_pressure, true, release);
should_swap = true;
}
#endif
if (swapout_target_age) {
should_swap = true;
}
#endif /* (XNU_TARGET_OS_OSX && __arm64__) */
check_if_low_space:
#if CONFIG_JETSAM
if (should_swap || vm_compressor_low_on_space() == TRUE) {
if (vm_compressor_thrashing_detected == FALSE) {
vm_compressor_thrashing_detected = TRUE;
if (swapout_target_age) {
compressor_thrashing_induced_jetsam++;
} else if (vm_compressor_low_on_space() == TRUE) {
compressor_thrashing_induced_jetsam++;
} else {
filecache_thrashing_induced_jetsam++;
}
/*
* Wake up the memorystatus thread so that it can return
* the system to a healthy state (by killing processes).
*/
memorystatus_thread_wake();
}
/*
* let the jetsam take precedence over
* any major compactions we might have
* been able to do... otherwise we run
* the risk of doing major compactions
* on segments we're about to free up
* due to the jetsam activity.
*/
should_swap = false;
if (memorystatus_swap_all_apps && vm_swap_low_on_space()) {
vm_compressor_take_paging_space_action();
}
}
#else /* CONFIG_JETSAM */
if (should_swap && vm_swap_low_on_space()) {
vm_compressor_take_paging_space_action();
}
#endif /* CONFIG_JETSAM */
if (should_swap == false) {
/*
* vm_compressor_needs_to_major_compact returns true only if we're
* about to run out of available compressor segments... in this
* case, we absolutely need to run a major compaction even if
* we've just kicked off a jetsam or we don't otherwise need to
* swap... terminating objects releases
* pages back to the uncompressed cache, but does not guarantee
* that we will free up even a single compression segment
*/
should_swap = vm_compressor_needs_to_major_compact();
if (should_swap) {
vmcs_stats.fragmentation_detected++;
}
}
/*
* returning TRUE when swap_supported == FALSE
* will cause the major compaction engine to
* run, but will not trigger any swapping...
* segments that have been major compacted
* will be moved to the majorcompact queue
*/
return should_swap;
}
#if CONFIG_JETSAM
/*
* This function is called from the jetsam thread after killing something to
* mitigate thrashing.
*
* We need to restart our thrashing detection heuristics since memory pressure
* has potentially changed significantly, and we don't want to detect on old
* data from before the jetsam.
*/
void
vm_thrashing_jetsam_done(void)
{
vm_compressor_thrashing_detected = FALSE;
/* Were we compressor-thrashing or filecache-thrashing? */
if (swapout_target_age) {
swapout_target_age = 0;
compressor_need_sample_reset = TRUE;
}
#if CONFIG_PHANTOM_CACHE
else {
vm_phantom_cache_restart_sample();
}
#endif
}
#endif /* CONFIG_JETSAM */
uint32_t vm_wake_compactor_swapper_calls = 0;
uint32_t vm_run_compactor_already_running = 0;
uint32_t vm_run_compactor_empty_minor_q = 0;
uint32_t vm_run_compactor_did_compact = 0;
uint32_t vm_run_compactor_waited = 0;
/* run minor compaction right now, if the compaction-swapper thread is not already running */
void
vm_run_compactor(void)
{
if (c_segment_count == 0) {
return;
}
if (os_atomic_load(&c_minor_count, relaxed) == 0) {
vm_run_compactor_empty_minor_q++;
return;
}
lck_mtx_lock_spin_always(c_list_lock);
if (compaction_swapper_running) {
if (vm_pageout_state.vm_restricted_to_single_processor == FALSE) {
vm_run_compactor_already_running++;
lck_mtx_unlock_always(c_list_lock);
return;
}
vm_run_compactor_waited++;
assert_wait((event_t)&compaction_swapper_running, THREAD_UNINT);
lck_mtx_unlock_always(c_list_lock);
thread_block(THREAD_CONTINUE_NULL);
return;
}
vm_run_compactor_did_compact++;
fastwake_warmup = FALSE;
compaction_swapper_running = 1;
vm_compressor_do_delayed_compactions(FALSE);
compaction_swapper_running = 0;
lck_mtx_unlock_always(c_list_lock);
thread_wakeup((event_t)&compaction_swapper_running);
}
void
vm_wake_compactor_swapper(void)
{
if (compaction_swapper_running || compaction_swapper_awakened || c_segment_count == 0) {
return;
}
if (os_atomic_load(&c_minor_count, relaxed) ||
vm_compressor_needs_to_major_compact()) {
lck_mtx_lock_spin_always(c_list_lock);
fastwake_warmup = FALSE;
if (compaction_swapper_running == 0 && compaction_swapper_awakened == 0) {
vm_wake_compactor_swapper_calls++;
compaction_swapper_awakened = 1;
thread_wakeup((event_t)&c_compressor_swap_trigger);
}
lck_mtx_unlock_always(c_list_lock);
}
}
void
vm_consider_swapping()
{
assert(VM_CONFIG_SWAP_IS_PRESENT);
lck_mtx_lock_spin_always(c_list_lock);
compaction_swapper_abort = 1;
while (compaction_swapper_running) {
assert_wait((event_t)&compaction_swapper_running, THREAD_UNINT);
lck_mtx_unlock_always(c_list_lock);
thread_block(THREAD_CONTINUE_NULL);
lck_mtx_lock_spin_always(c_list_lock);
}
compaction_swapper_abort = 0;
compaction_swapper_running = 1;
vm_swapout_ripe_segments = TRUE;
vm_compressor_process_major_segments(vm_swapout_ripe_segments);
vm_compressor_compact_and_swap(FALSE);
compaction_swapper_running = 0;
vm_swapout_ripe_segments = FALSE;
lck_mtx_unlock_always(c_list_lock);
thread_wakeup((event_t)&compaction_swapper_running);
}
void
vm_consider_waking_compactor_swapper(void)
{
bool need_wakeup = false;
if (c_segment_count == 0) {
return;
}
if (compaction_swapper_running || compaction_swapper_awakened) {
return;
}
if (!compaction_swapper_inited && !compaction_swapper_init_now) {
compaction_swapper_init_now = 1;
need_wakeup = true;
} else if (vm_compressor_needs_to_minor_compact() ||
compressor_needs_to_swap()) {
need_wakeup = true;
}
if (need_wakeup) {
lck_mtx_lock_spin_always(c_list_lock);
fastwake_warmup = FALSE;
if (compaction_swapper_running == 0 && compaction_swapper_awakened == 0) {
memoryshot(DBG_VM_WAKEUP_COMPACTOR_SWAPPER, DBG_FUNC_NONE);
compaction_swapper_awakened = 1;
thread_wakeup((event_t)&c_compressor_swap_trigger);
}
lck_mtx_unlock_always(c_list_lock);
}
}
#define C_SWAPOUT_LIMIT 4
#define DELAYED_COMPACTIONS_PER_PASS 30
/* process segments that are in the minor compaction queue */
void
vm_compressor_do_delayed_compactions(boolean_t flush_all)
{
c_segment_t c_seg;
int number_compacted = 0;
boolean_t needs_to_swap = FALSE;
uint32_t c_swapout_count = 0;
VM_DEBUG_CONSTANT_EVENT(vm_compressor_do_delayed_compactions, DBG_VM_COMPRESSOR_DELAYED_COMPACT, DBG_FUNC_START, c_minor_count, flush_all, 0, 0);
#if XNU_TARGET_OS_OSX
LCK_MTX_ASSERT(c_list_lock, LCK_MTX_ASSERT_OWNED);
#endif /* XNU_TARGET_OS_OSX */
while (!queue_empty(&c_minor_list_head) && needs_to_swap == FALSE) {
c_seg = (c_segment_t)queue_first(&c_minor_list_head);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (c_seg->c_busy) {
lck_mtx_unlock_always(c_list_lock);
c_seg_wait_on_busy(c_seg);
lck_mtx_lock_spin_always(c_list_lock);
continue;
}
C_SEG_BUSY(c_seg);
c_seg_do_minor_compaction_and_unlock(c_seg, TRUE, FALSE, TRUE);
c_swapout_count = c_early_swapout_count + c_regular_swapout_count + c_late_swapout_count;
if (VM_CONFIG_SWAP_IS_ACTIVE && (number_compacted++ > DELAYED_COMPACTIONS_PER_PASS)) {
if ((flush_all == TRUE || compressor_needs_to_swap()) && c_swapout_count < C_SWAPOUT_LIMIT) {
needs_to_swap = TRUE;
}
number_compacted = 0;
}
lck_mtx_lock_spin_always(c_list_lock);
}
VM_DEBUG_CONSTANT_EVENT(vm_compressor_do_delayed_compactions, DBG_VM_COMPRESSOR_DELAYED_COMPACT, DBG_FUNC_END, c_minor_count, number_compacted, needs_to_swap, 0);
}
int min_csegs_per_major_compaction = DELAYED_COMPACTIONS_PER_PASS;
static bool
vm_compressor_major_compact_cseg(c_segment_t c_seg, uint32_t* c_seg_considered, bool* bail_wanted_cseg, uint64_t* total_bytes_freed)
{
/*
* Major compaction
*/
bool keep_compacting = true, fully_compacted = true;
queue_head_t *list_head = NULL;
c_segment_t c_seg_next;
uint64_t bytes_to_free = 0, bytes_freed = 0;
uint32_t number_considered = 0;
if (c_seg->c_state == C_ON_AGE_Q) {
assert(!c_seg->c_has_donated_pages);
list_head = &c_age_list_head;
} else if (c_seg->c_state == C_ON_SWAPPEDIN_Q) {
assert(c_seg->c_has_donated_pages);
list_head = &c_late_swappedin_list_head;
}
while (keep_compacting == TRUE) {
assert(c_seg->c_busy);
/* look for another segment to consolidate */
c_seg_next = (c_segment_t) queue_next(&c_seg->c_age_list);
if (queue_end(list_head, (queue_entry_t)c_seg_next)) {
break;
}
assert(c_seg_next->c_state == c_seg->c_state);
number_considered++;
if (c_seg_major_compact_ok(c_seg, c_seg_next) == FALSE) {
break;
}
lck_mtx_lock_spin_always(&c_seg_next->c_lock);
if (c_seg_next->c_busy) {
/*
* We are going to block for our neighbor.
* If our c_seg is wanted, we should unbusy
* it because we don't know how long we might
* have to block here.
*/
if (c_seg->c_wanted) {
lck_mtx_unlock_always(&c_seg_next->c_lock);
fully_compacted = false;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].bailed_compactions++;
*bail_wanted_cseg = true;
break;
}
lck_mtx_unlock_always(c_list_lock);
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 8, (void*) VM_KERNEL_ADDRPERM(c_seg_next), 0, 0);
c_seg_wait_on_busy(c_seg_next);
lck_mtx_lock_spin_always(c_list_lock);
continue;
}
/* grab that segment */
C_SEG_BUSY(c_seg_next);
bytes_to_free = C_SEG_OFFSET_TO_BYTES(c_seg_next->c_populated_offset);
if (c_seg_do_minor_compaction_and_unlock(c_seg_next, FALSE, TRUE, TRUE)) {
/*
* found an empty c_segment and freed it
* so we can't continue to use c_seg_next
*/
bytes_freed += bytes_to_free;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].count_of_freed_segs++;
continue;
}
/* unlock the list ... */
lck_mtx_unlock_always(c_list_lock);
/* do the major compaction */
keep_compacting = c_seg_major_compact(c_seg, c_seg_next);
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 9, keep_compacting, 0, 0);
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg_next->c_lock);
/*
* run a minor compaction on the donor segment
* since we pulled at least some of it's
* data into our target... if we've emptied
* it, now is a good time to free it which
* c_seg_minor_compaction_and_unlock also takes care of
*
* by passing TRUE, we ask for c_busy to be cleared
* and c_wanted to be taken care of
*/
bytes_to_free = C_SEG_OFFSET_TO_BYTES(c_seg_next->c_populated_offset);
if (c_seg_minor_compaction_and_unlock(c_seg_next, TRUE)) {
bytes_freed += bytes_to_free;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].count_of_freed_segs++;
} else {
bytes_to_free -= C_SEG_OFFSET_TO_BYTES(c_seg_next->c_populated_offset);
bytes_freed += bytes_to_free;
}
PAGE_REPLACEMENT_DISALLOWED(FALSE);
/* relock the list */
lck_mtx_lock_spin_always(c_list_lock);
if (c_seg->c_wanted) {
/*
* Our c_seg is in demand. Let's
* unbusy it and wakeup the waiters
* instead of continuing the compaction
* because we could be in this loop
* for a while.
*/
fully_compacted = false;
*bail_wanted_cseg = true;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].bailed_compactions++;
break;
}
} /* major compaction */
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 10, number_considered, *bail_wanted_cseg, 0);
*c_seg_considered += number_considered;
*total_bytes_freed += bytes_freed;
lck_mtx_lock_spin_always(&c_seg->c_lock);
return fully_compacted;
}
#define TIME_SUB(rsecs, secs, rfrac, frac, unit) \
MACRO_BEGIN \
if ((int)((rfrac) -= (frac)) < 0) { \
(rfrac) += (unit); \
(rsecs) -= 1; \
} \
(rsecs) -= (secs); \
MACRO_END
clock_nsec_t c_process_major_report_over_ms = 9; /* report if over 9 ms */
int c_process_major_yield_after = 1000; /* yield after moving 1,000 segments */
uint64_t c_process_major_reports = 0;
clock_sec_t c_process_major_max_sec = 0;
clock_nsec_t c_process_major_max_nsec = 0;
uint32_t c_process_major_peak_segcount = 0;
static void
vm_compressor_process_major_segments(bool ripe_age_only)
{
c_segment_t c_seg = NULL;
int count = 0, total = 0, breaks = 0;
clock_sec_t start_sec, end_sec;
clock_nsec_t start_nsec, end_nsec;
clock_nsec_t report_over_ns;
if (queue_empty(&c_major_list_head)) {
return;
}
// printf("%s: starting to move segments from MAJORQ to AGEQ\n", __FUNCTION__);
if (c_process_major_report_over_ms != 0) {
report_over_ns = c_process_major_report_over_ms * NSEC_PER_MSEC;
} else {
report_over_ns = (clock_nsec_t)-1;
}
if (ripe_age_only) {
if (c_overage_swapped_count >= c_overage_swapped_limit) {
/*
* Return while we wait for the overage segments
* in our queue to get pushed out first.
*/
return;
}
}
clock_get_system_nanotime(&start_sec, &start_nsec);
while (!queue_empty(&c_major_list_head)) {
if (!ripe_age_only) {
/*
* Start from the end to preserve aging order. The newer
* segments are at the tail and so need to be inserted in
* the aging queue in this way so we have the older segments
* at the end of the AGE_Q.
*/
c_seg = (c_segment_t)queue_last(&c_major_list_head);
} else {
c_seg = (c_segment_t)queue_first(&c_major_list_head);
if ((start_sec - c_seg->c_creation_ts) < vm_ripe_target_age) {
/*
* We have found the first segment in our queue that is not ripe. Segments after it
* will be the same. So let's bail here. Return with c_list_lock held.
*/
break;
}
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
lck_mtx_unlock_always(&c_seg->c_lock);
count++;
if (count == c_process_major_yield_after ||
queue_empty(&c_major_list_head)) {
/* done or time to take a break */
} else {
/* keep going */
continue;
}
total += count;
clock_get_system_nanotime(&end_sec, &end_nsec);
TIME_SUB(end_sec, start_sec, end_nsec, start_nsec, NSEC_PER_SEC);
if (end_sec > c_process_major_max_sec) {
c_process_major_max_sec = end_sec;
c_process_major_max_nsec = end_nsec;
} else if (end_sec == c_process_major_max_sec &&
end_nsec > c_process_major_max_nsec) {
c_process_major_max_nsec = end_nsec;
}
if (total > c_process_major_peak_segcount) {
c_process_major_peak_segcount = total;
}
if (end_sec > 0 ||
end_nsec >= report_over_ns) {
/* we used more than expected */
c_process_major_reports++;
printf("%s: moved %d/%d segments from MAJORQ to AGEQ in %lu.%09u seconds and %d breaks\n",
__FUNCTION__, count, total,
end_sec, end_nsec, breaks);
}
if (queue_empty(&c_major_list_head)) {
/* done */
break;
}
/* take a break to allow someone else to grab the lock */
lck_mtx_unlock_always(c_list_lock);
mutex_pause(0); /* 10 microseconds */
lck_mtx_lock_spin_always(c_list_lock);
/* start again */
clock_get_system_nanotime(&start_sec, &start_nsec);
count = 0;
breaks++;
}
}
/*
* macOS special swappable csegs -> early_swapin queue
* non-macOS special swappable+non-freezer csegs -> late_swapin queue
* Processing special csegs means minor compacting each cseg and then
* major compacting it and putting them on the early or late
* (depending on platform) swapout queue. tag:DONATE
*/
static void
vm_compressor_process_special_swapped_in_segments_locked(void)
{
c_segment_t c_seg = NULL;
bool switch_state = true, bail_wanted_cseg = false;
unsigned int number_considered = 0, yield_after_considered_per_pass = 0;
uint64_t bytes_freed = 0;
queue_head_t *special_swappedin_list_head;
#if XNU_TARGET_OS_OSX
special_swappedin_list_head = &c_early_swappedin_list_head;
#else /* XNU_TARGET_OS_OSX */
if (memorystatus_swap_all_apps) {
special_swappedin_list_head = &c_late_swappedin_list_head;
} else {
/* called on unsupported config*/
return;
}
#endif /* XNU_TARGET_OS_OSX */
yield_after_considered_per_pass = MAX(min_csegs_per_major_compaction, DELAYED_COMPACTIONS_PER_PASS);
while (!queue_empty(special_swappedin_list_head)) {
c_seg = (c_segment_t)queue_first(special_swappedin_list_head);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (c_seg->c_busy) {
lck_mtx_unlock_always(c_list_lock);
c_seg_wait_on_busy(c_seg);
lck_mtx_lock_spin_always(c_list_lock);
continue;
}
C_SEG_BUSY(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_unlock_always(c_list_lock);
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (c_seg_minor_compaction_and_unlock(c_seg, FALSE /*clear busy?*/)) {
/*
* found an empty c_segment and freed it
* so go grab the next guy in the queue
*/
PAGE_REPLACEMENT_DISALLOWED(FALSE);
lck_mtx_lock_spin_always(c_list_lock);
continue;
}
PAGE_REPLACEMENT_DISALLOWED(FALSE);
lck_mtx_lock_spin_always(c_list_lock);
switch_state = vm_compressor_major_compact_cseg(c_seg, &number_considered, &bail_wanted_cseg, &bytes_freed);
assert(c_seg->c_busy);
assert(!c_seg->c_on_minorcompact_q);
if (switch_state) {
if (VM_CONFIG_SWAP_IS_ACTIVE || VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
/*
* Ordinarily we let swapped in segments age out + get
* major compacted with the rest of the c_segs on the ageQ.
* But the early donated c_segs, if well compacted, should be
* kept ready to be swapped out if needed. These are typically
* describing memory belonging to a leaky app (macOS) or a swap-
* capable app (iPadOS) and for the latter we can keep these
* around longer because we control the triggers in the memorystatus
* subsystem
*/
c_seg_switch_state(c_seg, C_ON_SWAPOUT_Q, FALSE);
}
}
C_SEG_WAKEUP_DONE(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
if (number_considered >= yield_after_considered_per_pass) {
if (bail_wanted_cseg) {
/*
* We stopped major compactions on a c_seg
* that is wanted. We don't know the priority
* of the waiter unfortunately but we are at
* a very high priority and so, just in case
* the waiter is a critical system daemon or
* UI thread, let's give up the CPU in case
* the system is running a few CPU intensive
* tasks.
*/
bail_wanted_cseg = false;
lck_mtx_unlock_always(c_list_lock);
mutex_pause(2); /* 100us yield */
lck_mtx_lock_spin_always(c_list_lock);
}
number_considered = 0;
}
}
}
void
vm_compressor_process_special_swapped_in_segments(void)
{
lck_mtx_lock_spin_always(c_list_lock);
vm_compressor_process_special_swapped_in_segments_locked();
lck_mtx_unlock_always(c_list_lock);
}
#define C_SEGMENT_SWAPPEDIN_AGE_LIMIT 10
/*
* Processing regular csegs means aging them.
*/
static void
vm_compressor_process_regular_swapped_in_segments(boolean_t flush_all)
{
c_segment_t c_seg;
clock_sec_t now;
clock_nsec_t nsec;
clock_get_system_nanotime(&now, &nsec);
while (!queue_empty(&c_regular_swappedin_list_head)) {
c_seg = (c_segment_t)queue_first(&c_regular_swappedin_list_head);
if (flush_all == FALSE && (now - c_seg->c_swappedin_ts) < C_SEGMENT_SWAPPEDIN_AGE_LIMIT) {
break;
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
c_seg->c_agedin_ts = (uint32_t) now;
lck_mtx_unlock_always(&c_seg->c_lock);
}
}
extern int vm_num_swap_files;
extern int vm_num_pinned_swap_files;
extern int vm_swappin_enabled;
extern unsigned int vm_swapfile_total_segs_used;
extern unsigned int vm_swapfile_total_segs_alloced;
void
vm_compressor_flush(void)
{
uint64_t vm_swap_put_failures_at_start;
wait_result_t wait_result = 0;
AbsoluteTime startTime, endTime;
clock_sec_t now_sec;
clock_nsec_t now_nsec;
uint64_t nsec;
c_segment_t c_seg, c_seg_next;
HIBLOG("vm_compressor_flush - starting\n");
clock_get_uptime(&startTime);
lck_mtx_lock_spin_always(c_list_lock);
fastwake_warmup = FALSE;
compaction_swapper_abort = 1;
while (compaction_swapper_running) {
assert_wait((event_t)&compaction_swapper_running, THREAD_UNINT);
lck_mtx_unlock_always(c_list_lock);
thread_block(THREAD_CONTINUE_NULL);
lck_mtx_lock_spin_always(c_list_lock);
}
compaction_swapper_abort = 0;
compaction_swapper_running = 1;
hibernate_flushing = TRUE;
hibernate_no_swapspace = FALSE;
hibernate_flush_timed_out = FALSE;
c_generation_id_flush_barrier = c_generation_id + 1000;
clock_get_system_nanotime(&now_sec, &now_nsec);
hibernate_flushing_deadline = now_sec + HIBERNATE_FLUSHING_SECS_TO_COMPLETE;
vm_swap_put_failures_at_start = vm_swap_put_failures;
/*
* We are about to hibernate and so we want all segments flushed to disk.
* Segments that are on the major compaction queue won't be considered in
* the vm_compressor_compact_and_swap() pass. So we need to bring them to
* the ageQ for consideration.
*/
if (!queue_empty(&c_major_list_head)) {
c_seg = (c_segment_t)queue_first(&c_major_list_head);
while (!queue_end(&c_major_list_head, (queue_entry_t)c_seg)) {
c_seg_next = (c_segment_t) queue_next(&c_seg->c_age_list);
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
lck_mtx_unlock_always(&c_seg->c_lock);
c_seg = c_seg_next;
}
}
vm_compressor_compact_and_swap(TRUE);
while (!queue_empty(&c_early_swapout_list_head) || !queue_empty(&c_regular_swapout_list_head) || !queue_empty(&c_late_swapout_list_head)) {
assert_wait_timeout((event_t) &compaction_swapper_running, THREAD_INTERRUPTIBLE, 5000, 1000 * NSEC_PER_USEC);
lck_mtx_unlock_always(c_list_lock);
wait_result = thread_block(THREAD_CONTINUE_NULL);
lck_mtx_lock_spin_always(c_list_lock);
if (wait_result == THREAD_TIMED_OUT) {
break;
}
}
hibernate_flushing = FALSE;
compaction_swapper_running = 0;
if (vm_swap_put_failures > vm_swap_put_failures_at_start) {
HIBLOG("vm_compressor_flush failed to clean %llu segments - vm_page_compressor_count(%d)\n",
vm_swap_put_failures - vm_swap_put_failures_at_start, VM_PAGE_COMPRESSOR_COUNT);
}
lck_mtx_unlock_always(c_list_lock);
thread_wakeup((event_t)&compaction_swapper_running);
clock_get_uptime(&endTime);
SUB_ABSOLUTETIME(&endTime, &startTime);
absolutetime_to_nanoseconds(endTime, &nsec);
HIBLOG("vm_compressor_flush completed - took %qd msecs - vm_num_swap_files = %d, vm_num_pinned_swap_files = %d, vm_swappin_enabled = %d\n",
nsec / 1000000ULL, vm_num_swap_files, vm_num_pinned_swap_files, vm_swappin_enabled);
}
int compaction_swap_trigger_thread_awakened = 0;
static void
vm_compressor_swap_trigger_thread(void)
{
current_thread()->options |= TH_OPT_VMPRIV;
/*
* compaction_swapper_init_now is set when the first call to
* vm_consider_waking_compactor_swapper is made from
* vm_pageout_scan... since this function is called upon
* thread creation, we want to make sure to delay adjusting
* the tuneables until we are awakened via vm_pageout_scan
* so that we are at a point where the vm_swapfile_open will
* be operating on the correct directory (in case the default
* of using the VM volume is overridden by the dynamic_pager)
*/
if (compaction_swapper_init_now) {
vm_compaction_swapper_do_init();
if (vm_pageout_state.vm_restricted_to_single_processor == TRUE) {
thread_vm_bind_group_add();
}
#if CONFIG_THREAD_GROUPS
thread_group_vm_add();
#endif
thread_set_thread_name(current_thread(), "VM_cswap_trigger");
compaction_swapper_init_now = 0;
}
lck_mtx_lock_spin_always(c_list_lock);
compaction_swap_trigger_thread_awakened++;
compaction_swapper_awakened = 0;
if (compaction_swapper_running == 0) {
compaction_swapper_running = 1;
vm_compressor_compact_and_swap(FALSE);
compaction_swapper_running = 0;
}
assert_wait((event_t)&c_compressor_swap_trigger, THREAD_UNINT);
if (compaction_swapper_running == 0) {
thread_wakeup((event_t)&compaction_swapper_running);
}
lck_mtx_unlock_always(c_list_lock);
thread_block((thread_continue_t)vm_compressor_swap_trigger_thread);
/* NOTREACHED */
}
void
vm_compressor_record_warmup_start(void)
{
c_segment_t c_seg;
lck_mtx_lock_spin_always(c_list_lock);
if (first_c_segment_to_warm_generation_id == 0) {
if (!queue_empty(&c_age_list_head)) {
c_seg = (c_segment_t)queue_last(&c_age_list_head);
first_c_segment_to_warm_generation_id = c_seg->c_generation_id;
} else {
first_c_segment_to_warm_generation_id = 0;
}
fastwake_recording_in_progress = TRUE;
}
lck_mtx_unlock_always(c_list_lock);
}
void
vm_compressor_record_warmup_end(void)
{
c_segment_t c_seg;
lck_mtx_lock_spin_always(c_list_lock);
if (fastwake_recording_in_progress == TRUE) {
if (!queue_empty(&c_age_list_head)) {
c_seg = (c_segment_t)queue_last(&c_age_list_head);
last_c_segment_to_warm_generation_id = c_seg->c_generation_id;
} else {
last_c_segment_to_warm_generation_id = first_c_segment_to_warm_generation_id;
}
fastwake_recording_in_progress = FALSE;
HIBLOG("vm_compressor_record_warmup (%qd - %qd)\n", first_c_segment_to_warm_generation_id, last_c_segment_to_warm_generation_id);
}
lck_mtx_unlock_always(c_list_lock);
}
#define DELAY_TRIM_ON_WAKE_NS (25 * NSEC_PER_SEC)
void
vm_compressor_delay_trim(void)
{
uint64_t now = mach_absolute_time();
uint64_t delay_abstime;
nanoseconds_to_absolutetime(DELAY_TRIM_ON_WAKE_NS, &delay_abstime);
dont_trim_until_ts = now + delay_abstime;
}
void
vm_compressor_do_warmup(void)
{
lck_mtx_lock_spin_always(c_list_lock);
if (first_c_segment_to_warm_generation_id == last_c_segment_to_warm_generation_id) {
first_c_segment_to_warm_generation_id = last_c_segment_to_warm_generation_id = 0;
lck_mtx_unlock_always(c_list_lock);
return;
}
if (compaction_swapper_running == 0 && compaction_swapper_awakened == 0) {
fastwake_warmup = TRUE;
compaction_swapper_awakened = 1;
thread_wakeup((event_t)&c_compressor_swap_trigger);
}
lck_mtx_unlock_always(c_list_lock);
}
void
do_fastwake_warmup_all(void)
{
lck_mtx_lock_spin_always(c_list_lock);
if (queue_empty(&c_swappedout_list_head) && queue_empty(&c_swappedout_sparse_list_head)) {
lck_mtx_unlock_always(c_list_lock);
return;
}
fastwake_warmup = TRUE;
do_fastwake_warmup(&c_swappedout_list_head, TRUE);
do_fastwake_warmup(&c_swappedout_sparse_list_head, TRUE);
fastwake_warmup = FALSE;
lck_mtx_unlock_always(c_list_lock);
}
void
do_fastwake_warmup(queue_head_t *c_queue, boolean_t consider_all_cseg)
{
c_segment_t c_seg = NULL;
AbsoluteTime startTime, endTime;
uint64_t nsec;
HIBLOG("vm_compressor_fastwake_warmup (%qd - %qd) - starting\n", first_c_segment_to_warm_generation_id, last_c_segment_to_warm_generation_id);
clock_get_uptime(&startTime);
lck_mtx_unlock_always(c_list_lock);
proc_set_thread_policy(current_thread(),
TASK_POLICY_INTERNAL, TASK_POLICY_IO, THROTTLE_LEVEL_COMPRESSOR_TIER2);
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(c_list_lock);
while (!queue_empty(c_queue) && fastwake_warmup == TRUE) {
c_seg = (c_segment_t) queue_first(c_queue);
if (consider_all_cseg == FALSE) {
if (c_seg->c_generation_id < first_c_segment_to_warm_generation_id ||
c_seg->c_generation_id > last_c_segment_to_warm_generation_id) {
break;
}
if (vm_page_free_count < (AVAILABLE_MEMORY / 4)) {
break;
}
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
lck_mtx_unlock_always(c_list_lock);
if (c_seg->c_busy) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
c_seg_wait_on_busy(c_seg);
PAGE_REPLACEMENT_DISALLOWED(TRUE);
} else {
if (c_seg_swapin(c_seg, TRUE, FALSE) == 0) {
lck_mtx_unlock_always(&c_seg->c_lock);
}
c_segment_warmup_count++;
PAGE_REPLACEMENT_DISALLOWED(FALSE);
vm_pageout_io_throttle();
PAGE_REPLACEMENT_DISALLOWED(TRUE);
}
lck_mtx_lock_spin_always(c_list_lock);
}
lck_mtx_unlock_always(c_list_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
proc_set_thread_policy(current_thread(),
TASK_POLICY_INTERNAL, TASK_POLICY_IO, THROTTLE_LEVEL_COMPRESSOR_TIER0);
clock_get_uptime(&endTime);
SUB_ABSOLUTETIME(&endTime, &startTime);
absolutetime_to_nanoseconds(endTime, &nsec);
HIBLOG("vm_compressor_fastwake_warmup completed - took %qd msecs\n", nsec / 1000000ULL);
lck_mtx_lock_spin_always(c_list_lock);
if (consider_all_cseg == FALSE) {
first_c_segment_to_warm_generation_id = last_c_segment_to_warm_generation_id = 0;
}
}
extern bool vm_swapout_thread_running;
extern boolean_t compressor_store_stop_compaction;
void
vm_compressor_compact_and_swap(boolean_t flush_all)
{
c_segment_t c_seg;
bool switch_state, bail_wanted_cseg = false;
clock_sec_t now;
clock_nsec_t nsec;
mach_timespec_t start_ts, end_ts;
unsigned int number_considered, wanted_cseg_found, yield_after_considered_per_pass, number_yields;
uint64_t bytes_freed, delta_usec;
uint32_t c_swapout_count = 0;
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_START, c_age_count, c_minor_count, c_major_count, vm_page_free_count);
if (fastwake_warmup == TRUE) {
uint64_t starting_warmup_count;
starting_warmup_count = c_segment_warmup_count;
KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 11) | DBG_FUNC_START, c_segment_warmup_count,
first_c_segment_to_warm_generation_id, last_c_segment_to_warm_generation_id, 0, 0);
do_fastwake_warmup(&c_swappedout_list_head, FALSE);
KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 11) | DBG_FUNC_END, c_segment_warmup_count, c_segment_warmup_count - starting_warmup_count, 0, 0, 0);
fastwake_warmup = FALSE;
}
#if (XNU_TARGET_OS_OSX && __arm64__)
/*
* Re-considering major csegs showed benefits on all platforms by
* significantly reducing fragmentation and getting back memory.
* However, on smaller devices, eg watch, there was increased power
* use for the additional compactions. And the turnover in csegs on
* those smaller platforms is high enough in the decompression/free
* path that we can skip reconsidering them here because we already
* consider them for major compaction in those paths.
*/
vm_compressor_process_major_segments(false /*all segments and not just the ripe-aged ones*/);
#endif /* (XNU_TARGET_OS_OSX && __arm64__) */
/*
* it's possible for the c_age_list_head to be empty if we
* hit our limits for growing the compressor pool and we subsequently
* hibernated... on the next hibernation we could see the queue as
* empty and not proceeed even though we have a bunch of segments on
* the swapped in queue that need to be dealt with.
*/
vm_compressor_do_delayed_compactions(flush_all);
vm_compressor_process_special_swapped_in_segments_locked();
vm_compressor_process_regular_swapped_in_segments(flush_all);
/*
* we only need to grab the timestamp once per
* invocation of this function since the
* timescale we're interested in is measured
* in days
*/
clock_get_system_nanotime(&now, &nsec);
start_ts.tv_sec = (int) now;
start_ts.tv_nsec = nsec;
delta_usec = 0;
number_considered = 0;
wanted_cseg_found = 0;
number_yields = 0;
bytes_freed = 0;
yield_after_considered_per_pass = MAX(min_csegs_per_major_compaction, DELAYED_COMPACTIONS_PER_PASS);
#if 0
/**
* SW: Need to figure out how to properly rate limit this log because it is currently way too
* noisy. rdar://99379414 (Figure out how to rate limit the fragmentation level logging)
*/
os_log(OS_LOG_DEFAULT, "memorystatus: before compaction fragmentation level %u\n", vm_compressor_fragmentation_level());
#endif
while (!queue_empty(&c_age_list_head) && !compaction_swapper_abort && !compressor_store_stop_compaction) {
if (hibernate_flushing == TRUE) {
clock_sec_t sec;
if (hibernate_should_abort()) {
HIBLOG("vm_compressor_flush - hibernate_should_abort returned TRUE\n");
break;
}
if (hibernate_no_swapspace == TRUE) {
HIBLOG("vm_compressor_flush - out of swap space\n");
break;
}
if (vm_swap_files_pinned() == FALSE) {
HIBLOG("vm_compressor_flush - unpinned swap files\n");
break;
}
if (hibernate_in_progress_with_pinned_swap == TRUE &&
(vm_swapfile_total_segs_alloced == vm_swapfile_total_segs_used)) {
HIBLOG("vm_compressor_flush - out of pinned swap space\n");
break;
}
clock_get_system_nanotime(&sec, &nsec);
if (sec > hibernate_flushing_deadline) {
hibernate_flush_timed_out = TRUE;
HIBLOG("vm_compressor_flush - failed to finish before deadline\n");
break;
}
}
c_swapout_count = c_early_swapout_count + c_regular_swapout_count + c_late_swapout_count;
if (VM_CONFIG_SWAP_IS_ACTIVE && !vm_swap_out_of_space() && c_swapout_count >= C_SWAPOUT_LIMIT) {
assert_wait_timeout((event_t) &compaction_swapper_running, THREAD_INTERRUPTIBLE, 100, 1000 * NSEC_PER_USEC);
if (!vm_swapout_thread_running) {
thread_wakeup((event_t)&vm_swapout_thread);
}
lck_mtx_unlock_always(c_list_lock);
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 1, c_swapout_count, 0, 0);
thread_block(THREAD_CONTINUE_NULL);
lck_mtx_lock_spin_always(c_list_lock);
}
/*
* Minor compactions
*/
vm_compressor_do_delayed_compactions(flush_all);
/*
* vm_compressor_process_early_swapped_in_segments()
* might be too aggressive. So OFF for now.
*/
vm_compressor_process_regular_swapped_in_segments(flush_all);
/* Recompute because we dropped the c_list_lock above*/
c_swapout_count = c_early_swapout_count + c_regular_swapout_count + c_late_swapout_count;
if (VM_CONFIG_SWAP_IS_ACTIVE && !vm_swap_out_of_space() && c_swapout_count >= C_SWAPOUT_LIMIT) {
/*
* we timed out on the above thread_block
* let's loop around and try again
* the timeout allows us to continue
* to do minor compactions to make
* more memory available
*/
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 2, c_swapout_count, 0, 0);
continue;
}
/*
* Swap out segments?
*/
if (flush_all == FALSE) {
bool needs_to_swap;
lck_mtx_unlock_always(c_list_lock);
needs_to_swap = compressor_needs_to_swap();
lck_mtx_lock_spin_always(c_list_lock);
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 3, needs_to_swap, 0, 0);
if (!needs_to_swap) {
break;
}
}
if (queue_empty(&c_age_list_head)) {
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 4, c_age_count, 0, 0);
break;
}
c_seg = (c_segment_t) queue_first(&c_age_list_head);
assert(c_seg->c_state == C_ON_AGE_Q);
if (flush_all == TRUE && c_seg->c_generation_id > c_generation_id_flush_barrier) {
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 5, 0, 0, 0);
break;
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (c_seg->c_busy) {
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 6, (void*) VM_KERNEL_ADDRPERM(c_seg), 0, 0);
lck_mtx_unlock_always(c_list_lock);
c_seg_wait_on_busy(c_seg);
lck_mtx_lock_spin_always(c_list_lock);
continue;
}
C_SEG_BUSY(c_seg);
if (c_seg_do_minor_compaction_and_unlock(c_seg, FALSE, TRUE, TRUE)) {
/*
* found an empty c_segment and freed it
* so go grab the next guy in the queue
*/
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 7, 0, 0, 0);
c_seg_major_compact_stats[c_seg_major_compact_stats_now].count_of_freed_segs++;
continue;
}
switch_state = vm_compressor_major_compact_cseg(c_seg, &number_considered, &bail_wanted_cseg, &bytes_freed);
if (bail_wanted_cseg) {
wanted_cseg_found++;
bail_wanted_cseg = false;
}
assert(c_seg->c_busy);
assert(!c_seg->c_on_minorcompact_q);
if (switch_state) {
if (VM_CONFIG_SWAP_IS_ACTIVE) {
int new_state = C_ON_SWAPOUT_Q;
#if (XNU_TARGET_OS_OSX && __arm64__)
if (flush_all == false && compressor_swapout_conditions_met() == false) {
new_state = C_ON_MAJORCOMPACT_Q;
}
#endif /* (XNU_TARGET_OS_OSX && __arm64__) */
if (new_state == C_ON_SWAPOUT_Q) {
/*
* This mode of putting a generic c_seg on the swapout list is
* only supported when we have general swapping enabled
*/
clock_sec_t lnow;
clock_nsec_t lnsec;
clock_get_system_nanotime(&lnow, &lnsec);
if (c_seg->c_agedin_ts && (lnow - c_seg->c_agedin_ts) < 30) {
vmcs_stats.unripe_under_30s++;
} else if (c_seg->c_agedin_ts && (lnow - c_seg->c_agedin_ts) < 60) {
vmcs_stats.unripe_under_60s++;
} else if (c_seg->c_agedin_ts && (lnow - c_seg->c_agedin_ts) < 300) {
vmcs_stats.unripe_under_300s++;
}
}
c_seg_switch_state(c_seg, new_state, FALSE);
} else {
if ((vm_swapout_ripe_segments == TRUE && c_overage_swapped_count < c_overage_swapped_limit)) {
assert(VM_CONFIG_SWAP_IS_PRESENT);
/*
* we are running compressor sweeps with swap-behind
* make sure the c_seg has aged enough before swapping it
* out...
*/
if ((now - c_seg->c_creation_ts) >= vm_ripe_target_age) {
c_seg->c_overage_swap = TRUE;
c_overage_swapped_count++;
c_seg_switch_state(c_seg, C_ON_SWAPOUT_Q, FALSE);
}
}
}
if (c_seg->c_state == C_ON_AGE_Q) {
/*
* this c_seg didn't get moved to the swapout queue
* so we need to move it out of the way...
* we just did a major compaction on it so put it
* on that queue
*/
c_seg_switch_state(c_seg, C_ON_MAJORCOMPACT_Q, FALSE);
} else {
c_seg_major_compact_stats[c_seg_major_compact_stats_now].wasted_space_in_swapouts += c_seg_bufsize - c_seg->c_bytes_used;
c_seg_major_compact_stats[c_seg_major_compact_stats_now].count_of_swapouts++;
}
}
C_SEG_WAKEUP_DONE(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
/*
* On systems _with_ general swap, regardless of jetsam, we wake up the swapout thread here.
* On systems _without_ general swap, it's the responsibility of the memorystatus
* subsystem to wake up the swapper.
* TODO: When we have full jetsam support on a swap enabled system, we will need to revisit
* this policy.
*/
if (VM_CONFIG_SWAP_IS_ACTIVE && c_swapout_count) {
/*
* We don't pause/yield here because we will either
* yield below or at the top of the loop with the
* assert_wait_timeout.
*/
if (!vm_swapout_thread_running) {
thread_wakeup((event_t)&vm_swapout_thread);
}
}
if (number_considered >= yield_after_considered_per_pass) {
if (wanted_cseg_found) {
/*
* We stopped major compactions on a c_seg
* that is wanted. We don't know the priority
* of the waiter unfortunately but we are at
* a very high priority and so, just in case
* the waiter is a critical system daemon or
* UI thread, let's give up the CPU in case
* the system is running a few CPU intensive
* tasks.
*/
lck_mtx_unlock_always(c_list_lock);
mutex_pause(2); /* 100us yield */
number_yields++;
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_NONE, 11, number_considered, number_yields, 0);
lck_mtx_lock_spin_always(c_list_lock);
}
number_considered = 0;
wanted_cseg_found = 0;
}
}
clock_get_system_nanotime(&now, &nsec);
end_ts = major_compact_ts = (mach_timespec_t){.tv_sec = (int)now, .tv_nsec = nsec};
SUB_MACH_TIMESPEC(&end_ts, &start_ts);
delta_usec = (end_ts.tv_sec * USEC_PER_SEC) + (end_ts.tv_nsec / NSEC_PER_USEC) - (number_yields * 100);
delta_usec = MAX(1, delta_usec); /* we could have 0 usec run if conditions weren't right */
c_seg_major_compact_stats[c_seg_major_compact_stats_now].bytes_freed_rate_us = (bytes_freed / delta_usec);
if ((c_seg_major_compact_stats_now + 1) == C_SEG_MAJOR_COMPACT_STATS_MAX) {
c_seg_major_compact_stats_now = 0;
} else {
c_seg_major_compact_stats_now++;
}
assert(c_seg_major_compact_stats_now < C_SEG_MAJOR_COMPACT_STATS_MAX);
VM_DEBUG_CONSTANT_EVENT(vm_compressor_compact_and_swap, DBG_VM_COMPRESSOR_COMPACT_AND_SWAP, DBG_FUNC_END, c_age_count, c_minor_count, c_major_count, vm_page_free_count);
}
static c_segment_t
c_seg_allocate(c_segment_t *current_chead)
{
c_segment_t c_seg;
int min_needed;
int size_to_populate;
c_segment_t *donate_queue_head;
#if XNU_TARGET_OS_OSX
if (vm_compressor_low_on_space()) {
vm_compressor_take_paging_space_action();
}
#endif /* XNU_TARGET_OS_OSX */
if ((c_seg = *current_chead) == NULL) {
uint32_t c_segno;
lck_mtx_lock_spin_always(c_list_lock);
while (c_segments_busy == TRUE) {
assert_wait((event_t) (&c_segments_busy), THREAD_UNINT);
lck_mtx_unlock_always(c_list_lock);
thread_block(THREAD_CONTINUE_NULL);
lck_mtx_lock_spin_always(c_list_lock);
}
if (c_free_segno_head == (uint32_t)-1) {
uint32_t c_segments_available_new;
uint32_t compressed_pages;
#if CONFIG_FREEZE
if (freezer_incore_cseg_acct) {
compressed_pages = c_segment_pages_compressed_incore;
} else {
compressed_pages = c_segment_pages_compressed;
}
#else
compressed_pages = c_segment_pages_compressed;
#endif /* CONFIG_FREEZE */
if (c_segments_available >= c_segments_limit || compressed_pages >= c_segment_pages_compressed_limit) {
lck_mtx_unlock_always(c_list_lock);
return NULL;
}
c_segments_busy = TRUE;
lck_mtx_unlock_always(c_list_lock);
/* pages for c_segments are never depopulated, c_segments_available never goes down */
kernel_memory_populate((vm_offset_t)c_segments_next_page,
PAGE_SIZE, KMA_NOFAIL | KMA_KOBJECT,
VM_KERN_MEMORY_COMPRESSOR);
c_segments_next_page += PAGE_SIZE;
c_segments_available_new = c_segments_available + C_SEGMENTS_PER_PAGE;
if (c_segments_available_new > c_segments_limit) {
c_segments_available_new = c_segments_limit;
}
/* add the just-added segments to the top of the free-list */
for (c_segno = c_segments_available + 1; c_segno < c_segments_available_new; c_segno++) {
c_segments[c_segno - 1].c_segno = c_segno; /* next free is the one after you */
}
lck_mtx_lock_spin_always(c_list_lock);
c_segments[c_segno - 1].c_segno = c_free_segno_head; /* link to the rest of, existing freelist */
c_free_segno_head = c_segments_available; /* first one in the page that was just allocated */
c_segments_available = c_segments_available_new;
c_segments_busy = FALSE;
thread_wakeup((event_t) (&c_segments_busy));
}
c_segno = c_free_segno_head;
assert(c_segno >= 0 && c_segno < c_segments_limit);
c_free_segno_head = (uint32_t)c_segments[c_segno].c_segno;
/*
* do the rest of the bookkeeping now while we're still behind
* the list lock and grab our generation id now into a local
* so that we can install it once we have the c_seg allocated
*/
c_segment_count++;
if (c_segment_count > c_segment_count_max) {
c_segment_count_max = c_segment_count;
}
lck_mtx_unlock_always(c_list_lock);
c_seg = zalloc_flags(compressor_segment_zone, Z_WAITOK | Z_ZERO);
c_seg->c_store.c_buffer = (int32_t *)C_SEG_BUFFER_ADDRESS(c_segno);
lck_mtx_init(&c_seg->c_lock, &vm_compressor_lck_grp, LCK_ATTR_NULL);
c_seg->c_state = C_IS_EMPTY;
c_seg->c_firstemptyslot = C_SLOT_MAX_INDEX;
c_seg->c_mysegno = c_segno;
lck_mtx_lock_spin_always(c_list_lock);
c_empty_count++; /* going to be immediately decremented in the next call */
c_seg_switch_state(c_seg, C_IS_FILLING, FALSE);
c_segments[c_segno].c_seg = c_seg;
assert(c_segments[c_segno].c_segno > c_segments_available); /* we just assigned a pointer to it so this is an indication that it is occupied */
lck_mtx_unlock_always(c_list_lock);
for (int i = 0; i < vm_pageout_state.vm_compressor_thread_count; i++) {
#if XNU_TARGET_OS_OSX /* tag:DONATE */
donate_queue_head = (c_segment_t*) &(pgo_iothread_internal_state[i].current_early_swapout_chead);
#else /* XNU_TARGET_OS_OSX */
if (memorystatus_swap_all_apps) {
donate_queue_head = (c_segment_t*) &(pgo_iothread_internal_state[i].current_late_swapout_chead);
} else {
donate_queue_head = NULL;
}
#endif /* XNU_TARGET_OS_OSX */
if (current_chead == donate_queue_head) {
c_seg->c_has_donated_pages = 1;
break;
}
}
*current_chead = c_seg;
#if DEVELOPMENT || DEBUG
C_SEG_MAKE_WRITEABLE(c_seg);
#endif
}
c_seg_alloc_nextslot(c_seg);
size_to_populate = c_seg_allocsize - C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset);
if (size_to_populate) {
min_needed = PAGE_SIZE + (c_seg_allocsize - c_seg_bufsize);
if (C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset - c_seg->c_nextoffset) < (unsigned) min_needed) {
if (size_to_populate > C_SEG_MAX_POPULATE_SIZE) {
size_to_populate = C_SEG_MAX_POPULATE_SIZE;
}
OSAddAtomic64(size_to_populate / PAGE_SIZE, &vm_pageout_vminfo.vm_compressor_pages_grabbed);
kernel_memory_populate(
(vm_offset_t) &c_seg->c_store.c_buffer[c_seg->c_populated_offset],
size_to_populate,
KMA_NOFAIL | KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
} else {
size_to_populate = 0;
}
}
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (size_to_populate) {
c_seg->c_populated_offset += C_SEG_BYTES_TO_OFFSET(size_to_populate);
}
return c_seg;
}
#if DEVELOPMENT || DEBUG
#if CONFIG_FREEZE
extern boolean_t memorystatus_freeze_to_memory;
#endif /* CONFIG_FREEZE */
#endif /* DEVELOPMENT || DEBUG */
uint64_t c_seg_total_donated_bytes = 0; /* For testing/debugging only for now. Remove and add new counters for vm_stat.*/
uint64_t c_seg_filled_no_contention = 0;
uint64_t c_seg_filled_contention = 0;
clock_sec_t c_seg_filled_contention_sec_max = 0;
clock_nsec_t c_seg_filled_contention_nsec_max = 0;
static void
c_current_seg_filled(c_segment_t c_seg, c_segment_t *current_chead)
{
uint32_t unused_bytes;
uint32_t offset_to_depopulate;
int new_state = C_ON_AGE_Q;
clock_sec_t sec;
clock_nsec_t nsec;
bool head_insert = false, wakeup_swapout_thread = false;
unused_bytes = trunc_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset - c_seg->c_nextoffset));
if (unused_bytes) {
/* if this is a platform that need an extra page at the end of the segment when running compress
* then now is the time to depopulate that extra page. it still takes virtual space but doesn't
* actually waste memory */
offset_to_depopulate = C_SEG_BYTES_TO_OFFSET(round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_nextoffset)));
/* release the extra physical page(s) at the end of the segment */
lck_mtx_unlock_always(&c_seg->c_lock);
kernel_memory_depopulate(
(vm_offset_t) &c_seg->c_store.c_buffer[offset_to_depopulate],
unused_bytes,
KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_seg->c_populated_offset = offset_to_depopulate;
}
assert(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset) <= c_seg_bufsize);
#if DEVELOPMENT || DEBUG
{
boolean_t c_seg_was_busy = FALSE;
if (!c_seg->c_busy) {
C_SEG_BUSY(c_seg);
} else {
c_seg_was_busy = TRUE;
}
lck_mtx_unlock_always(&c_seg->c_lock);
C_SEG_WRITE_PROTECT(c_seg);
lck_mtx_lock_spin_always(&c_seg->c_lock);
if (c_seg_was_busy == FALSE) {
C_SEG_WAKEUP_DONE(c_seg);
}
}
#endif
#if CONFIG_FREEZE
if (current_chead == (c_segment_t*) &(freezer_context_global.freezer_ctx_chead) &&
VM_CONFIG_SWAP_IS_PRESENT &&
VM_CONFIG_FREEZER_SWAP_IS_ACTIVE
#if DEVELOPMENT || DEBUG
&& !memorystatus_freeze_to_memory
#endif /* DEVELOPMENT || DEBUG */
) {
new_state = C_ON_SWAPOUT_Q;
wakeup_swapout_thread = true;
}
#endif /* CONFIG_FREEZE */
if (vm_darkwake_mode == TRUE) {
new_state = C_ON_SWAPOUT_Q;
head_insert = true;
wakeup_swapout_thread = true;
} else {
c_segment_t *donate_queue_head;
for (int i = 0; i < vm_pageout_state.vm_compressor_thread_count; i++) {
#if XNU_TARGET_OS_OSX /* tag:DONATE */
donate_queue_head = (c_segment_t*) &(pgo_iothread_internal_state[i].current_early_swapout_chead);
#else /* XNU_TARGET_OS_OSX */
donate_queue_head = (c_segment_t*) &(pgo_iothread_internal_state[i].current_late_swapout_chead);
#endif /* XNU_TARGET_OS_OSX */
if (current_chead == donate_queue_head) {
/* This is the place where the "donating" task actually does the so-called donation
* Instead of continueing to take place in memory in the compressor, the segment goes directly
* to swap-out instead of going to AGE_Q */
assert(c_seg->c_has_donated_pages);
new_state = C_ON_SWAPOUT_Q;
c_seg_total_donated_bytes += c_seg->c_bytes_used;
break;
}
}
}
clock_get_system_nanotime(&sec, &nsec);
c_seg->c_creation_ts = (uint32_t)sec;
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
clock_sec_t sec2;
clock_nsec_t nsec2;
lck_mtx_lock_spin_always(c_list_lock);
clock_get_system_nanotime(&sec2, &nsec2);
TIME_SUB(sec2, sec, nsec2, nsec, NSEC_PER_SEC);
/* keep track of how much time we've waited for c_list_lock */
if (sec2 > c_seg_filled_contention_sec_max) {
c_seg_filled_contention_sec_max = sec2;
c_seg_filled_contention_nsec_max = nsec2;
} else if (sec2 == c_seg_filled_contention_sec_max && nsec2 > c_seg_filled_contention_nsec_max) {
c_seg_filled_contention_nsec_max = nsec2;
}
c_seg_filled_contention++;
} else {
c_seg_filled_no_contention++;
}
#if CONFIG_FREEZE
if (current_chead == (c_segment_t*) &(freezer_context_global.freezer_ctx_chead)) {
if (freezer_context_global.freezer_ctx_task->donates_own_pages) {
assert(!c_seg->c_has_donated_pages);
c_seg->c_has_donated_pages = 1;
OSAddAtomic(c_seg->c_slots_used, &c_segment_pages_compressed_incore_late_swapout);
}
c_seg->c_has_freezer_pages = 1;
}
#endif /* CONFIG_FREEZE */
c_seg->c_generation_id = c_generation_id++;
c_seg_switch_state(c_seg, new_state, head_insert);
#if CONFIG_FREEZE
/*
* Donated segments count as frozen to swap if we go through the freezer.
* TODO: What we need is a new ledger and cseg state that can describe
* a frozen cseg from a donated task so we can accurately decrement it on
* swapins.
*/
if (current_chead == (c_segment_t*) &(freezer_context_global.freezer_ctx_chead) && (c_seg->c_state == C_ON_SWAPOUT_Q)) {
/*
* darkwake and freezer can't co-exist together
* We'll need to fix this accounting as a start.
* And early donation c_segs are separate from frozen c_segs.
*/
assert(vm_darkwake_mode == FALSE);
c_seg_update_task_owner(c_seg, freezer_context_global.freezer_ctx_task);
freezer_context_global.freezer_ctx_swapped_bytes += c_seg->c_bytes_used;
}
#endif /* CONFIG_FREEZE */
if (c_seg->c_state == C_ON_AGE_Q && C_SEG_UNUSED_BYTES(c_seg) >= PAGE_SIZE) {
/* this is possible if we decompressed a page from the segment before it ended filling */
#if CONFIG_FREEZE
assert(c_seg->c_task_owner == NULL);
#endif /* CONFIG_FREEZE */
c_seg_need_delayed_compaction(c_seg, TRUE);
}
lck_mtx_unlock_always(c_list_lock);
if (wakeup_swapout_thread) {
/*
* Darkwake and Freeze configs always
* wake up the swapout thread because
* the compactor thread that normally handles
* it may not be running as much in these
* configs.
*/
thread_wakeup((event_t)&vm_swapout_thread);
}
*current_chead = NULL;
}
/*
* returns with c_seg locked
*/
void
c_seg_swapin_requeue(c_segment_t c_seg, boolean_t has_data, boolean_t minor_compact_ok, boolean_t age_on_swapin_q)
{
clock_sec_t sec;
clock_nsec_t nsec;
clock_get_system_nanotime(&sec, &nsec);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
assert(c_seg->c_busy_swapping);
assert(c_seg->c_busy);
c_seg->c_busy_swapping = 0;
if (c_seg->c_overage_swap == TRUE) {
c_overage_swapped_count--;
c_seg->c_overage_swap = FALSE;
}
if (has_data == TRUE) {
if (age_on_swapin_q == TRUE || c_seg->c_has_donated_pages) {
#if CONFIG_FREEZE
/*
* If a segment has both identities, frozen and donated bits set, the donated
* bit wins on the swapin path. This is because the segment is being swapped back
* in and so is in demand and should be given more time to spend in memory before
* being swapped back out under pressure.
*/
if (c_seg->c_has_donated_pages) {
c_seg->c_has_freezer_pages = 0;
}
#endif /* CONFIG_FREEZE */
c_seg_switch_state(c_seg, C_ON_SWAPPEDIN_Q, FALSE);
} else {
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
}
if (minor_compact_ok == TRUE && !c_seg->c_on_minorcompact_q && C_SEG_UNUSED_BYTES(c_seg) >= PAGE_SIZE) {
c_seg_need_delayed_compaction(c_seg, TRUE);
}
} else {
c_seg->c_store.c_buffer = (int32_t*) NULL;
c_seg->c_populated_offset = C_SEG_BYTES_TO_OFFSET(0);
c_seg_switch_state(c_seg, C_ON_BAD_Q, FALSE);
}
c_seg->c_swappedin_ts = (uint32_t)sec;
c_seg->c_swappedin = true;
#if TRACK_C_SEGMENT_UTILIZATION
c_seg->c_decompressions_since_swapin = 0;
#endif /* TRACK_C_SEGMENT_UTILIZATION */
lck_mtx_unlock_always(c_list_lock);
}
/*
* c_seg has to be locked and is returned locked if the c_seg isn't freed
* PAGE_REPLACMENT_DISALLOWED has to be TRUE on entry and is returned TRUE
* c_seg_swapin returns 1 if the c_seg was freed, 0 otherwise
*/
int
c_seg_swapin(c_segment_t c_seg, boolean_t force_minor_compaction, boolean_t age_on_swapin_q)
{
vm_offset_t addr = 0;
uint32_t io_size = 0;
uint64_t f_offset;
thread_pri_floor_t token;
assert(C_SEG_IS_ONDISK(c_seg));
#if !CHECKSUM_THE_SWAP
c_seg_trim_tail(c_seg);
#endif
io_size = round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset));
f_offset = c_seg->c_store.c_swap_handle;
C_SEG_BUSY(c_seg);
c_seg->c_busy_swapping = 1;
/*
* This thread is likely going to block for I/O.
* Make sure it is ready to run when the I/O completes because
* it needs to clear the busy bit on the c_seg so that other
* waiting threads can make progress too.
*/
token = thread_priority_floor_start();
lck_mtx_unlock_always(&c_seg->c_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
addr = (vm_offset_t)C_SEG_BUFFER_ADDRESS(c_seg->c_mysegno);
c_seg->c_store.c_buffer = (int32_t*) addr;
kernel_memory_populate(addr, io_size, KMA_NOFAIL | KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
if (vm_swap_get(c_seg, f_offset, io_size) != KERN_SUCCESS) {
PAGE_REPLACEMENT_DISALLOWED(TRUE);
kernel_memory_depopulate(addr, io_size, KMA_COMPRESSOR,
VM_KERN_MEMORY_COMPRESSOR);
c_seg_swapin_requeue(c_seg, FALSE, TRUE, age_on_swapin_q);
} else {
#if ENCRYPTED_SWAP
vm_swap_decrypt(c_seg);
#endif /* ENCRYPTED_SWAP */
#if CHECKSUM_THE_SWAP
if (c_seg->cseg_swap_size != io_size) {
panic("swapin size doesn't match swapout size");
}
if (c_seg->cseg_hash != vmc_hash((char*) c_seg->c_store.c_buffer, (int)io_size)) {
panic("c_seg_swapin - Swap hash mismatch");
}
#endif /* CHECKSUM_THE_SWAP */
PAGE_REPLACEMENT_DISALLOWED(TRUE);
c_seg_swapin_requeue(c_seg, TRUE, force_minor_compaction == TRUE ? FALSE : TRUE, age_on_swapin_q);
#if CONFIG_FREEZE
/*
* c_seg_swapin_requeue() returns with the c_seg lock held.
*/
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
assert(c_seg->c_busy);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
if (c_seg->c_task_owner) {
c_seg_update_task_owner(c_seg, NULL);
}
lck_mtx_unlock_always(c_list_lock);
OSAddAtomic(c_seg->c_slots_used, &c_segment_pages_compressed_incore);
if (c_seg->c_has_donated_pages) {
OSAddAtomic(c_seg->c_slots_used, &c_segment_pages_compressed_incore_late_swapout);
}
#endif /* CONFIG_FREEZE */
OSAddAtomic64(c_seg->c_bytes_used, &compressor_bytes_used);
if (force_minor_compaction == TRUE) {
if (c_seg_minor_compaction_and_unlock(c_seg, FALSE)) {
/*
* c_seg was completely empty so it was freed,
* so be careful not to reference it again
*
* Drop the boost so that the thread priority
* is returned back to where it is supposed to be.
*/
thread_priority_floor_end(&token);
return 1;
}
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
}
C_SEG_WAKEUP_DONE(c_seg);
/*
* Drop the boost so that the thread priority
* is returned back to where it is supposed to be.
*/
thread_priority_floor_end(&token);
return 0;
}
static void
c_segment_sv_hash_drop_ref(int hash_indx)
{
struct c_sv_hash_entry o_sv_he, n_sv_he;
while (1) {
o_sv_he.he_record = c_segment_sv_hash_table[hash_indx].he_record;
n_sv_he.he_ref = o_sv_he.he_ref - 1;
n_sv_he.he_data = o_sv_he.he_data;
if (OSCompareAndSwap64((UInt64)o_sv_he.he_record, (UInt64)n_sv_he.he_record, (UInt64 *) &c_segment_sv_hash_table[hash_indx].he_record) == TRUE) {
if (n_sv_he.he_ref == 0) {
OSAddAtomic(-1, &c_segment_svp_in_hash);
}
break;
}
}
}
static int
c_segment_sv_hash_insert(uint32_t data)
{
int hash_sindx;
int misses;
struct c_sv_hash_entry o_sv_he, n_sv_he;
boolean_t got_ref = FALSE;
if (data == 0) {
OSAddAtomic(1, &c_segment_svp_zero_compressions);
} else {
OSAddAtomic(1, &c_segment_svp_nonzero_compressions);
}
hash_sindx = data & C_SV_HASH_MASK;
for (misses = 0; misses < C_SV_HASH_MAX_MISS; misses++) {
o_sv_he.he_record = c_segment_sv_hash_table[hash_sindx].he_record;
while (o_sv_he.he_data == data || o_sv_he.he_ref == 0) {
n_sv_he.he_ref = o_sv_he.he_ref + 1;
n_sv_he.he_data = data;
if (OSCompareAndSwap64((UInt64)o_sv_he.he_record, (UInt64)n_sv_he.he_record, (UInt64 *) &c_segment_sv_hash_table[hash_sindx].he_record) == TRUE) {
if (n_sv_he.he_ref == 1) {
OSAddAtomic(1, &c_segment_svp_in_hash);
}
got_ref = TRUE;
break;
}
o_sv_he.he_record = c_segment_sv_hash_table[hash_sindx].he_record;
}
if (got_ref == TRUE) {
break;
}
hash_sindx++;
if (hash_sindx == C_SV_HASH_SIZE) {
hash_sindx = 0;
}
}
if (got_ref == FALSE) {
return -1;
}
return hash_sindx;
}
#if RECORD_THE_COMPRESSED_DATA
static void
c_compressed_record_data(char *src, int c_size)
{
if ((c_compressed_record_cptr + c_size + 4) >= c_compressed_record_ebuf) {
panic("c_compressed_record_cptr >= c_compressed_record_ebuf");
}
*(int *)((void *)c_compressed_record_cptr) = c_size;
c_compressed_record_cptr += 4;
memcpy(c_compressed_record_cptr, src, c_size);
c_compressed_record_cptr += c_size;
}
#endif
/**
* Do the actual compression of the given page
* @param src [IN] address in the physical aperture of the page to compress.
* @param slot_ptr [OUT] fill the slot-mapping of the c_seg+slot where the page ends up being stored
* @param current_chead [IN-OUT] current filling c_seg. pointer comes from the current compression thread state
* On the very first call this is going to point to NULL and this function will fill that pointer with a new
* filling c_sec if the current filling c_seg doesn't have enough space, it will be replaced in this location
* with a new filling c_seg
* @param scratch_buf [IN] pointer from the current thread state, used by the compression codec
* @return 0 on success, 1 on memory allocation error
*/
static int
c_compress_page(
char *src,
c_slot_mapping_t slot_ptr,
c_segment_t *current_chead,
char *scratch_buf,
__unused vm_compressor_options_t flags)
{
int c_size = -1;
int c_rounded_size = 0;
int max_csize;
c_slot_t cs;
c_segment_t c_seg;
KERNEL_DEBUG(0xe0400000 | DBG_FUNC_START, *current_chead, 0, 0, 0, 0);
retry: /* may need to retry if the currently filling c_seg will not have enough space */
if ((c_seg = c_seg_allocate(current_chead)) == NULL) {
return 1;
}
/*
* returns with c_seg lock held
* and PAGE_REPLACEMENT_DISALLOWED(TRUE)...
* c_nextslot has been allocated and
* c_store.c_buffer populated
*/
assert(c_seg->c_state == C_IS_FILLING);
cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_seg->c_nextslot);
C_SLOT_ASSERT_PACKABLE(slot_ptr);
cs->c_packed_ptr = C_SLOT_PACK_PTR(slot_ptr);
cs->c_offset = c_seg->c_nextoffset;
unsigned int avail_space = c_seg_bufsize - C_SEG_OFFSET_TO_BYTES((int32_t)cs->c_offset);
max_csize = avail_space;
if (max_csize > PAGE_SIZE) {
max_csize = PAGE_SIZE;
}
#if CHECKSUM_THE_DATA
cs->c_hash_data = vmc_hash(src, PAGE_SIZE);
#endif
boolean_t incomp_copy = FALSE; /* codec indicates it already did copy an incompressible page */
int max_csize_adj = (max_csize - 4); /* how much size we have left in this c_seg to fill. */
if (vm_compressor_algorithm() != VM_COMPRESSOR_DEFAULT_CODEC) {
#if defined(__arm64__)
uint16_t ccodec = CINVALID;
uint32_t inline_popcount;
if (max_csize >= C_SEG_OFFSET_ALIGNMENT_BOUNDARY) {
vm_memtag_disable_checking();
c_size = metacompressor((const uint8_t *) src,
(uint8_t *) &c_seg->c_store.c_buffer[cs->c_offset],
max_csize_adj, &ccodec,
scratch_buf, &incomp_copy, &inline_popcount);
vm_memtag_enable_checking();
assert(inline_popcount == C_SLOT_NO_POPCOUNT);
#if C_SEG_OFFSET_ALIGNMENT_BOUNDARY > 4
if (c_size > max_csize_adj) {
c_size = -1;
}
#endif
} else {
c_size = -1;
}
assert(ccodec == CCWK || ccodec == CCLZ4);
cs->c_codec = ccodec;
#endif
} else {
#if defined(__arm64__)
vm_memtag_disable_checking();
cs->c_codec = CCWK;
__unreachable_ok_push
if (PAGE_SIZE == 4096) {
c_size = WKdm_compress_4k((WK_word *)(uintptr_t)src, (WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)scratch_buf, max_csize_adj);
} else {
c_size = WKdm_compress_16k((WK_word *)(uintptr_t)src, (WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)scratch_buf, max_csize_adj);
}
__unreachable_ok_pop
vm_memtag_enable_checking();
#else
vm_memtag_disable_checking();
c_size = WKdm_compress_new((const WK_word *)(uintptr_t)src, (WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)scratch_buf, max_csize_adj);
vm_memtag_enable_checking();
#endif
}
/* c_size is the size written by the codec, or 0 if it's uniform 32 bit value or (-1 if there was not enough space
* or it was incompressible) */
assertf(((c_size <= max_csize_adj) && (c_size >= -1)),
"c_size invalid (%d, %d), cur compressions: %d", c_size, max_csize_adj, c_segment_pages_compressed);
if (c_size == -1) {
if (max_csize < PAGE_SIZE) {
c_current_seg_filled(c_seg, current_chead);
assert(*current_chead == NULL);
lck_mtx_unlock_always(&c_seg->c_lock);
/* TODO: it may be worth requiring codecs to distinguish
* between incompressible inputs and failures due to budget exhaustion.
* right now this assumes that if the space we had is > PAGE_SIZE, then the codec failed due to incompressible input */
PAGE_REPLACEMENT_DISALLOWED(FALSE);
goto retry; /* previous c_seg didn't have enought space, we finalized it and can try again with a fresh c_seg */
}
c_size = PAGE_SIZE;
if (incomp_copy == FALSE) { /* codec did not copy the incompressible input */
vm_memtag_disable_checking();
memcpy(&c_seg->c_store.c_buffer[cs->c_offset], src, c_size);
vm_memtag_enable_checking();
}
OSAddAtomic(1, &c_segment_noncompressible_pages);
} else if (c_size == 0) {
/*
* Special case - this is a page completely full of a single 32 bit value.
* We store some values directly in the c_slot_mapping, if not there, the
* 4 byte value goes in the compressor segment.
*/
int hash_index = c_segment_sv_hash_insert(*(uint32_t *)(uintptr_t)src);
if (hash_index != -1
) {
slot_ptr->s_cindx = hash_index;
slot_ptr->s_cseg = C_SV_CSEG_ID;
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
slot_ptr->s_uncompressed = 0;
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
OSAddAtomic(1, &c_segment_svp_hash_succeeded);
#if RECORD_THE_COMPRESSED_DATA
c_compressed_record_data(src, 4);
#endif
/* we didn't write anything to c_buffer and didn't end up using the slot in the c_seg at all, so skip all
* the book-keeping of the case that we did */
goto sv_compression;
}
OSAddAtomic(1, &c_segment_svp_hash_failed);
c_size = 4;
vm_memtag_disable_checking();
memcpy(&c_seg->c_store.c_buffer[cs->c_offset], src, c_size);
vm_memtag_enable_checking();
}
#if RECORD_THE_COMPRESSED_DATA
c_compressed_record_data((char *)&c_seg->c_store.c_buffer[cs->c_offset], c_size);
#endif
#if CHECKSUM_THE_COMPRESSED_DATA
cs->c_hash_compressed_data = vmc_hash((char *)&c_seg->c_store.c_buffer[cs->c_offset], c_size);
#endif
#if POPCOUNT_THE_COMPRESSED_DATA
cs->c_pop_cdata = vmc_pop((uintptr_t) &c_seg->c_store.c_buffer[cs->c_offset], c_size);
#endif
PACK_C_SIZE(cs, c_size);
c_rounded_size = (c_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
c_seg->c_bytes_used += c_rounded_size;
c_seg->c_nextoffset += C_SEG_BYTES_TO_OFFSET(c_rounded_size);
c_seg->c_slots_used++;
#if CONFIG_FREEZE
/* TODO: should c_segment_pages_compressed be up here too? See 88598046 for details */
OSAddAtomic(1, &c_segment_pages_compressed_incore);
if (c_seg->c_has_donated_pages) {
OSAddAtomic(1, &c_segment_pages_compressed_incore_late_swapout);
}
#endif /* CONFIG_FREEZE */
slot_ptr->s_cindx = c_seg->c_nextslot++;
/* <csegno=0,indx=0> would mean "empty slot", so use csegno+1, see other usages of s_cseg where it's decremented */
slot_ptr->s_cseg = c_seg->c_mysegno + 1;
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
slot_ptr->s_uncompressed = 0;
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
sv_compression:
/* can we say this c_seg is full? */
if (c_seg->c_nextoffset >= c_seg_off_limit || c_seg->c_nextslot >= C_SLOT_MAX_INDEX) {
/* condition 1: segment buffer is almost full, don't bother trying to fill it further.
* condition 2: we can't have any more slots in this c_segment even if we had buffer space */
c_current_seg_filled(c_seg, current_chead);
assert(*current_chead == NULL);
}
lck_mtx_unlock_always(&c_seg->c_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
#if RECORD_THE_COMPRESSED_DATA
if ((c_compressed_record_cptr - c_compressed_record_sbuf) >= c_seg_allocsize) {
c_compressed_record_write(c_compressed_record_sbuf, (int)(c_compressed_record_cptr - c_compressed_record_sbuf));
c_compressed_record_cptr = c_compressed_record_sbuf;
}
#endif
if (c_size) {
OSAddAtomic64(c_size, &c_segment_compressed_bytes);
OSAddAtomic64(c_rounded_size, &compressor_bytes_used);
}
OSAddAtomic64(PAGE_SIZE, &c_segment_input_bytes);
OSAddAtomic(1, &c_segment_pages_compressed);
#if DEVELOPMENT || DEBUG
if (!compressor_running_perf_test) {
/*
* The perf_compressor benchmark should not be able to trigger
* compressor thrashing jetsams.
*/
OSAddAtomic(1, &sample_period_compression_count);
}
#else /* DEVELOPMENT || DEBUG */
OSAddAtomic(1, &sample_period_compression_count);
#endif /* DEVELOPMENT || DEBUG */
KERNEL_DEBUG(0xe0400000 | DBG_FUNC_END, *current_chead, c_size, c_segment_input_bytes, c_segment_compressed_bytes, 0);
return 0;
}
static inline void
sv_decompress(int32_t *ddst, int32_t pattern)
{
// assert(__builtin_constant_p(PAGE_SIZE) != 0);
#if defined(__x86_64__)
memset_word(ddst, pattern, PAGE_SIZE / sizeof(int32_t));
#elif defined(__arm64__)
assert((PAGE_SIZE % 128) == 0);
if (pattern == 0) {
fill32_dczva((addr64_t)ddst, PAGE_SIZE);
} else {
fill32_nt((addr64_t)ddst, PAGE_SIZE, pattern);
}
#else
size_t i;
/* Unroll the pattern fill loop 4x to encourage the
* compiler to emit NEON stores, cf.
* <rdar://problem/25839866> Loop autovectorization
* anomalies.
*/
/* * We use separate loops for each PAGE_SIZE
* to allow the autovectorizer to engage, as PAGE_SIZE
* may not be a constant.
*/
__unreachable_ok_push
if (PAGE_SIZE == 4096) {
for (i = 0; i < (4096U / sizeof(int32_t)); i += 4) {
*ddst++ = pattern;
*ddst++ = pattern;
*ddst++ = pattern;
*ddst++ = pattern;
}
} else {
assert(PAGE_SIZE == 16384);
for (i = 0; i < (int)(16384U / sizeof(int32_t)); i += 4) {
*ddst++ = pattern;
*ddst++ = pattern;
*ddst++ = pattern;
*ddst++ = pattern;
}
}
__unreachable_ok_pop
#endif
}
static int
c_decompress_page(
char *dst,
volatile c_slot_mapping_t slot_ptr, /* why volatile? perhaps due to changes across hibernation */
vm_compressor_options_t flags,
int *zeroslot)
{
c_slot_t cs;
c_segment_t c_seg;
uint32_t c_segno;
uint16_t c_indx;
int c_rounded_size;
uint32_t c_size;
int retval = 0;
boolean_t need_unlock = TRUE;
boolean_t consider_defragmenting = FALSE;
boolean_t kdp_mode = FALSE;
if (__improbable(flags & C_KDP)) {
if (not_in_kdp) {
panic("C_KDP passed to decompress page from outside of debugger context");
}
assert((flags & C_KEEP) == C_KEEP);
assert((flags & C_DONT_BLOCK) == C_DONT_BLOCK);
if ((flags & (C_DONT_BLOCK | C_KEEP)) != (C_DONT_BLOCK | C_KEEP)) {
return -2;
}
kdp_mode = TRUE;
*zeroslot = 0;
}
ReTry:
if (__probable(!kdp_mode)) {
PAGE_REPLACEMENT_DISALLOWED(TRUE);
} else {
if (kdp_lck_rw_lock_is_acquired_exclusive(&c_master_lock)) {
return -2;
}
}
#if HIBERNATION
/*
* if hibernation is enabled, it indicates (via a call
* to 'vm_decompressor_lock' that no further
* decompressions are allowed once it reaches
* the point of flushing all of the currently dirty
* anonymous memory through the compressor and out
* to disk... in this state we allow freeing of compressed
* pages and must honor the C_DONT_BLOCK case
*/
if (__improbable(dst && decompressions_blocked == TRUE)) {
if (flags & C_DONT_BLOCK) {
if (__probable(!kdp_mode)) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
*zeroslot = 0;
return -2;
}
/*
* it's safe to atomically assert and block behind the
* lock held in shared mode because "decompressions_blocked" is
* only set and cleared and the thread_wakeup done when the lock
* is held exclusively
*/
assert_wait((event_t)&decompressions_blocked, THREAD_UNINT);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
thread_block(THREAD_CONTINUE_NULL);
goto ReTry;
}
#endif
/* s_cseg is actually "segno+1" */
c_segno = slot_ptr->s_cseg - 1;
if (__improbable(c_segno >= c_segments_available)) {
panic("c_decompress_page: c_segno %d >= c_segments_available %d, slot_ptr(%p), slot_data(%x)",
c_segno, c_segments_available, slot_ptr, *(int *)((void *)slot_ptr));
}
if (__improbable(c_segments[c_segno].c_segno < c_segments_available)) {
panic("c_decompress_page: c_segno %d is free, slot_ptr(%p), slot_data(%x)",
c_segno, slot_ptr, *(int *)((void *)slot_ptr));
}
c_seg = c_segments[c_segno].c_seg;
if (__probable(!kdp_mode)) {
lck_mtx_lock_spin_always(&c_seg->c_lock);
} else {
if (kdp_lck_mtx_lock_spin_is_acquired(&c_seg->c_lock)) {
return -2;
}
}
assert(c_seg->c_state != C_IS_EMPTY && c_seg->c_state != C_IS_FREE);
if (dst == NULL && c_seg->c_busy_swapping) {
assert(c_seg->c_busy);
goto bypass_busy_check;
}
if (flags & C_DONT_BLOCK) {
if (c_seg->c_busy || (C_SEG_IS_ONDISK(c_seg) && dst)) {
*zeroslot = 0;
retval = -2;
goto done;
}
}
if (c_seg->c_busy) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
c_seg_wait_on_busy(c_seg);
goto ReTry;
}
bypass_busy_check:
c_indx = slot_ptr->s_cindx;
if (__improbable(c_indx >= c_seg->c_nextslot)) {
panic("c_decompress_page: c_indx %d >= c_nextslot %d, c_seg(%p), slot_ptr(%p), slot_data(%x)",
c_indx, c_seg->c_nextslot, c_seg, slot_ptr, *(int *)((void *)slot_ptr));
}
cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
c_size = UNPACK_C_SIZE(cs);
if (__improbable(c_size == 0)) { /* sanity check it's not an empty slot */
panic("c_decompress_page: c_size == 0, c_seg(%p), slot_ptr(%p), slot_data(%x)",
c_seg, slot_ptr, *(int *)((void *)slot_ptr));
}
c_rounded_size = (c_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
if (dst) { /* would be NULL if we don't want the page content, from free */
uint32_t age_of_cseg;
clock_sec_t cur_ts_sec;
clock_nsec_t cur_ts_nsec;
if (C_SEG_IS_ONDISK(c_seg)) {
#if CONFIG_FREEZE
if (freezer_incore_cseg_acct) {
if ((c_seg->c_slots_used + c_segment_pages_compressed_incore) >= c_segment_pages_compressed_nearing_limit) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
lck_mtx_unlock_always(&c_seg->c_lock);
memorystatus_kill_on_VM_compressor_space_shortage(FALSE /* async */);
goto ReTry;
}
uint32_t incore_seg_count = c_segment_count - c_swappedout_count - c_swappedout_sparse_count;
if ((incore_seg_count + 1) >= c_segments_nearing_limit) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
lck_mtx_unlock_always(&c_seg->c_lock);
memorystatus_kill_on_VM_compressor_space_shortage(FALSE /* async */);
goto ReTry;
}
}
#endif /* CONFIG_FREEZE */
assert(kdp_mode == FALSE);
retval = c_seg_swapin(c_seg, FALSE, TRUE);
assert(retval == 0);
retval = 1;
}
if (c_seg->c_state == C_ON_BAD_Q) {
assert(c_seg->c_store.c_buffer == NULL);
*zeroslot = 0;
retval = -1;
goto done;
}
#if POPCOUNT_THE_COMPRESSED_DATA
unsigned csvpop;
uintptr_t csvaddr = (uintptr_t) &c_seg->c_store.c_buffer[cs->c_offset];
if (cs->c_pop_cdata != (csvpop = vmc_pop(csvaddr, c_size))) {
panic("Compressed data popcount doesn't match original, bit distance: %d %p (phys: %p) %p %p 0x%x 0x%x 0x%x 0x%x", (csvpop - cs->c_pop_cdata), (void *)csvaddr, (void *) kvtophys(csvaddr), c_seg, cs, cs->c_offset, c_size, csvpop, cs->c_pop_cdata);
}
#endif
#if CHECKSUM_THE_COMPRESSED_DATA
unsigned csvhash;
if (cs->c_hash_compressed_data != (csvhash = vmc_hash((char *)&c_seg->c_store.c_buffer[cs->c_offset], c_size))) {
panic("Compressed data doesn't match original %p %p %u %u %u", c_seg, cs, c_size, cs->c_hash_compressed_data, csvhash);
}
#endif
if (c_rounded_size == PAGE_SIZE) {
/* page wasn't compressible... just copy it out */
vm_memtag_disable_checking();
memcpy(dst, &c_seg->c_store.c_buffer[cs->c_offset], PAGE_SIZE);
vm_memtag_enable_checking();
} else if (c_size == 4) {
int32_t data;
int32_t *dptr;
/*
* page was populated with a single value
* that didn't fit into our fast hash
* so we packed it in as a single non-compressed value
* that we need to populate the page with
*/
dptr = (int32_t *)(uintptr_t)dst;
data = *(int32_t *)(&c_seg->c_store.c_buffer[cs->c_offset]);
vm_memtag_disable_checking();
sv_decompress(dptr, data);
vm_memtag_enable_checking();
} else { /* normal segment decompress */
uint32_t my_cpu_no;
char *scratch_buf;
my_cpu_no = cpu_number();
assert(my_cpu_no < compressor_cpus);
if (__probable(!kdp_mode)) {
/*
* we're behind the c_seg lock held in spin mode
* which means pre-emption is disabled... therefore
* the following sequence is atomic and safe
*/
scratch_buf = &compressor_scratch_bufs[my_cpu_no * vm_compressor_get_decode_scratch_size()];
} else if (flags & C_KDP_MULTICPU) {
assert(vm_compressor_kdp_state.kc_scratch_bufs != NULL);
scratch_buf = &vm_compressor_kdp_state.kc_scratch_bufs[my_cpu_no * vm_compressor_get_decode_scratch_size()];
} else {
scratch_buf = vm_compressor_kdp_state.kc_panic_scratch_buf;
}
if (vm_compressor_algorithm() != VM_COMPRESSOR_DEFAULT_CODEC) {
#if defined(__arm64__)
uint16_t c_codec = cs->c_codec;
uint32_t inline_popcount;
vm_memtag_disable_checking();
if (!metadecompressor((const uint8_t *) &c_seg->c_store.c_buffer[cs->c_offset],
(uint8_t *)dst, c_size, c_codec, (void *)scratch_buf, &inline_popcount)) {
vm_memtag_enable_checking();
retval = -1;
} else {
vm_memtag_enable_checking();
assert(inline_popcount == C_SLOT_NO_POPCOUNT);
}
#endif
} else { /* algorithm == VM_COMPRESSOR_DEFAULT_CODEC */
vm_memtag_disable_checking();
#if defined(__arm64__)
__unreachable_ok_push
if (PAGE_SIZE == 4096) {
WKdm_decompress_4k((WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)dst, (WK_word *)(uintptr_t)scratch_buf, c_size);
} else {
WKdm_decompress_16k((WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)dst, (WK_word *)(uintptr_t)scratch_buf, c_size);
}
__unreachable_ok_pop
#else
WKdm_decompress_new((WK_word *)(uintptr_t)&c_seg->c_store.c_buffer[cs->c_offset],
(WK_word *)(uintptr_t)dst, (WK_word *)(uintptr_t)scratch_buf, c_size);
#endif
vm_memtag_enable_checking();
}
} /* normal segment decompress */
#if CHECKSUM_THE_DATA
if (cs->c_hash_data != vmc_hash(dst, PAGE_SIZE)) {
#if defined(__arm64__)
int32_t *dinput = &c_seg->c_store.c_buffer[cs->c_offset];
panic("decompressed data doesn't match original cs: %p, hash: 0x%x, offset: %d, c_size: %d, c_rounded_size: %d, codec: %d, header: 0x%x 0x%x 0x%x", cs, cs->c_hash_data, cs->c_offset, c_size, c_rounded_size, cs->c_codec, *dinput, *(dinput + 1), *(dinput + 2));
#else
panic("decompressed data doesn't match original cs: %p, hash: %d, offset: 0x%x, c_size: %d", cs, cs->c_hash_data, cs->c_offset, c_size);
#endif
}
#endif
if (c_seg->c_swappedin_ts == 0 && !kdp_mode) {
clock_get_system_nanotime(&cur_ts_sec, &cur_ts_nsec);
age_of_cseg = (uint32_t)cur_ts_sec - c_seg->c_creation_ts;
if (age_of_cseg < DECOMPRESSION_SAMPLE_MAX_AGE) {
OSAddAtomic(1, &age_of_decompressions_during_sample_period[age_of_cseg]);
} else {
OSAddAtomic(1, &overage_decompressions_during_sample_period);
}
OSAddAtomic(1, &sample_period_decompression_count);
}
#if TRACK_C_SEGMENT_UTILIZATION
if (c_seg->c_swappedin) {
c_seg->c_decompressions_since_swapin++;
}
#endif /* TRACK_C_SEGMENT_UTILIZATION */
} /* dst */
#if CONFIG_FREEZE
else {
/*
* We are freeing an uncompressed page from this c_seg and so balance the ledgers.
*/
if (C_SEG_IS_ONDISK(c_seg)) {
/*
* The compression sweep feature will push out anonymous pages to disk
* without going through the freezer path and so those c_segs, while
* swapped out, won't have an owner.
*/
if (c_seg->c_task_owner) {
task_update_frozen_to_swap_acct(c_seg->c_task_owner, PAGE_SIZE_64, DEBIT_FROM_SWAP);
}
/*
* We are freeing a page in swap without swapping it in. We bump the in-core
* count here to simulate a swapin of a page so that we can accurately
* decrement it below.
*/
OSAddAtomic(1, &c_segment_pages_compressed_incore);
if (c_seg->c_has_donated_pages) {
OSAddAtomic(1, &c_segment_pages_compressed_incore_late_swapout);
}
} else if (c_seg->c_state == C_ON_BAD_Q) {
assert(c_seg->c_store.c_buffer == NULL);
*zeroslot = 0;
retval = -1;
goto done;
}
}
#endif /* CONFIG_FREEZE */
if (flags & C_KEEP) {
*zeroslot = 0;
goto done;
}
/* now perform needed bookkeeping for the removal of the slot from the segment */
assert(kdp_mode == FALSE);
c_seg->c_bytes_unused += c_rounded_size;
c_seg->c_bytes_used -= c_rounded_size;
assert(c_seg->c_slots_used);
c_seg->c_slots_used--;
if (dst && c_seg->c_swappedin) {
task_t task = current_task();
if (task) {
ledger_credit(task->ledger, task_ledgers.swapins, PAGE_SIZE);
}
}
PACK_C_SIZE(cs, 0); /* mark slot as empty */
if (c_indx < c_seg->c_firstemptyslot) {
c_seg->c_firstemptyslot = c_indx;
}
OSAddAtomic(-1, &c_segment_pages_compressed);
#if CONFIG_FREEZE
OSAddAtomic(-1, &c_segment_pages_compressed_incore);
assertf(c_segment_pages_compressed_incore >= 0, "-ve incore count %p 0x%x", c_seg, c_segment_pages_compressed_incore);
if (c_seg->c_has_donated_pages) {
OSAddAtomic(-1, &c_segment_pages_compressed_incore_late_swapout);
assertf(c_segment_pages_compressed_incore_late_swapout >= 0, "-ve lateswapout count %p 0x%x", c_seg, c_segment_pages_compressed_incore_late_swapout);
}
#endif /* CONFIG_FREEZE */
if (c_seg->c_state != C_ON_BAD_Q && !(C_SEG_IS_ONDISK(c_seg))) {
/*
* C_SEG_IS_ONDISK == TRUE can occur when we're doing a
* free of a compressed page (i.e. dst == NULL)
*/
OSAddAtomic64(-c_rounded_size, &compressor_bytes_used);
}
if (c_seg->c_busy_swapping) {
/*
* bypass case for c_busy_swapping...
* let the swapin/swapout paths deal with putting
* the c_seg on the minor compaction queue if needed
*/
assert(c_seg->c_busy);
goto done;
}
assert(!c_seg->c_busy);
if (c_seg->c_state != C_IS_FILLING) {
/* did we just remove the last slot from the segment? */
if (c_seg->c_bytes_used == 0) {
if (!(C_SEG_IS_ONDISK(c_seg))) {
/* it was compressed resident in memory */
int pages_populated;
pages_populated = (round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset))) / PAGE_SIZE;
c_seg->c_populated_offset = C_SEG_BYTES_TO_OFFSET(0);
if (pages_populated) {
assert(c_seg->c_state != C_ON_BAD_Q);
assert(c_seg->c_store.c_buffer != NULL);
C_SEG_BUSY(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
kernel_memory_depopulate(
(vm_offset_t) c_seg->c_store.c_buffer,
ptoa(pages_populated),
KMA_COMPRESSOR, VM_KERN_MEMORY_COMPRESSOR);
lck_mtx_lock_spin_always(&c_seg->c_lock);
C_SEG_WAKEUP_DONE(c_seg);
}
/* minor compaction will free it */
if (!c_seg->c_on_minorcompact_q && c_seg->c_state != C_ON_SWAPIO_Q) {
if (c_seg->c_state == C_ON_SWAPOUT_Q) {
/* If we're on the swapout q, we want to get out of it since there's no reason to swapout
* anymore, so put on AGE Q in the meantime until minor compact */
bool clear_busy = false;
if (!lck_mtx_try_lock_spin_always(c_list_lock)) {
C_SEG_BUSY(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
lck_mtx_lock_spin_always(c_list_lock);
lck_mtx_lock_spin_always(&c_seg->c_lock);
clear_busy = true;
}
c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
if (clear_busy) {
C_SEG_WAKEUP_DONE(c_seg);
clear_busy = false;
}
lck_mtx_unlock_always(c_list_lock);
}
c_seg_need_delayed_compaction(c_seg, FALSE);
}
} else { /* C_SEG_IS_ONDISK(c_seg) */
/* it's empty and on-disk, make sure it's marked as sparse */
if (c_seg->c_state != C_ON_SWAPPEDOUTSPARSE_Q) {
c_seg_move_to_sparse_list(c_seg);
consider_defragmenting = TRUE;
}
}
} else if (c_seg->c_on_minorcompact_q) {
assert(c_seg->c_state != C_ON_BAD_Q);
assert(!C_SEG_IS_ON_DISK_OR_SOQ(c_seg));
if (C_SEG_SHOULD_MINORCOMPACT_NOW(c_seg)) {
c_seg_try_minor_compaction_and_unlock(c_seg);
need_unlock = FALSE;
}
} else if (!(C_SEG_IS_ONDISK(c_seg))) {
if (c_seg->c_state != C_ON_BAD_Q && c_seg->c_state != C_ON_SWAPOUT_Q && c_seg->c_state != C_ON_SWAPIO_Q &&
C_SEG_UNUSED_BYTES(c_seg) >= PAGE_SIZE) {
c_seg_need_delayed_compaction(c_seg, FALSE);
}
} else if (c_seg->c_state != C_ON_SWAPPEDOUTSPARSE_Q && C_SEG_ONDISK_IS_SPARSE(c_seg)) {
c_seg_move_to_sparse_list(c_seg);
consider_defragmenting = TRUE;
}
} /* c_state != C_IS_FILLING */
done:
if (__improbable(kdp_mode)) {
return retval;
}
if (need_unlock == TRUE) {
lck_mtx_unlock_always(&c_seg->c_lock);
}
PAGE_REPLACEMENT_DISALLOWED(FALSE);
if (consider_defragmenting == TRUE) {
vm_swap_consider_defragmenting(VM_SWAP_FLAGS_NONE);
}
#if !XNU_TARGET_OS_OSX
/*
* Decompressions will generate fragmentation in the compressor pool
* over time. Consider waking the compactor thread if any of the
* fragmentation thresholds have been crossed as a result of this
* decompression.
*/
vm_consider_waking_compactor_swapper();
#endif /* !XNU_TARGET_OS_OSX */
return retval;
}
inline bool
vm_compressor_is_slot_compressed(int *slot)
{
#if !CONFIG_TRACK_UNMODIFIED_ANON_PAGES
#pragma unused(slot)
return true;
#else /* !CONFIG_TRACK_UNMODIFIED_ANON_PAGES*/
c_slot_mapping_t slot_ptr = (c_slot_mapping_t)slot;
return !slot_ptr->s_uncompressed;
#endif /* !CONFIG_TRACK_UNMODIFIED_ANON_PAGES*/
}
int
vm_compressor_get(ppnum_t pn, int *slot, vm_compressor_options_t flags)
{
c_slot_mapping_t slot_ptr;
char *dst;
int zeroslot = 1;
int retval;
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
if (flags & C_PAGE_UNMODIFIED) {
retval = vm_uncompressed_get(pn, slot, flags | C_KEEP);
if (retval == 0) {
os_atomic_inc(&compressor_ro_uncompressed_get, relaxed);
}
return retval;
}
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
/* get address in physical aperture of this page for fill into */
dst = pmap_map_compressor_page(pn);
slot_ptr = (c_slot_mapping_t)slot;
assert(dst != NULL);
if (slot_ptr->s_cseg == C_SV_CSEG_ID) {
int32_t data;
int32_t *dptr;
/*
* page was populated with a single value
* that found a home in our hash table
* grab that value from the hash and populate the page
* that we need to populate the page with
*/
dptr = (int32_t *)(uintptr_t)dst;
data = c_segment_sv_hash_table[slot_ptr->s_cindx].he_data;
sv_decompress(dptr, data);
if (!(flags & C_KEEP)) {
c_segment_sv_hash_drop_ref(slot_ptr->s_cindx);
OSAddAtomic(-1, &c_segment_pages_compressed);
*slot = 0;
}
if (data) {
OSAddAtomic(1, &c_segment_svp_nonzero_decompressions);
} else {
OSAddAtomic(1, &c_segment_svp_zero_decompressions);
}
pmap_unmap_compressor_page(pn, dst);
return 0;
}
retval = c_decompress_page(dst, slot_ptr, flags, &zeroslot);
/*
* zeroslot will be set to 0 by c_decompress_page if (flags & C_KEEP)
* or (flags & C_DONT_BLOCK) and we found 'c_busy' or 'C_SEG_IS_ONDISK' to be TRUE
*/
if (zeroslot) {
*slot = 0;
}
pmap_unmap_compressor_page(pn, dst);
/*
* returns 0 if we successfully decompressed a page from a segment already in memory
* returns 1 if we had to first swap in the segment, before successfully decompressing the page
* returns -1 if we encountered an error swapping in the segment - decompression failed
* returns -2 if (flags & C_DONT_BLOCK) and we found 'c_busy' or 'C_SEG_IS_ONDISK' to be true
*/
return retval;
}
int
vm_compressor_free(int *slot, vm_compressor_options_t flags)
{
bool slot_is_compressed = vm_compressor_is_slot_compressed(slot);
if (slot_is_compressed) {
c_slot_mapping_t slot_ptr;
int zeroslot = 1;
int retval = 0;
assert(flags == 0 || flags == C_DONT_BLOCK);
slot_ptr = (c_slot_mapping_t)slot;
if (slot_ptr->s_cseg == C_SV_CSEG_ID) {
c_segment_sv_hash_drop_ref(slot_ptr->s_cindx);
OSAddAtomic(-1, &c_segment_pages_compressed);
*slot = 0;
return 0;
}
retval = c_decompress_page(NULL, slot_ptr, flags, &zeroslot);
/*
* returns 0 if we successfully freed the specified compressed page
* returns -1 if we encountered an error swapping in the segment - decompression failed
* returns -2 if (flags & C_DONT_BLOCK) and we found 'c_busy' set
*/
if (retval == 0) {
*slot = 0;
}
return retval;
}
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
else {
if ((flags & C_PAGE_UNMODIFIED) == 0) {
/* moving from uncompressed state to compressed. Free it.*/
vm_uncompressed_free(slot, 0);
assert(*slot == 0);
}
}
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
return KERN_SUCCESS;
}
int
vm_compressor_put(ppnum_t pn, int *slot, void **current_chead, char *scratch_buf, vm_compressor_options_t flags)
{
char *src;
int retval = 0;
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
if (flags & C_PAGE_UNMODIFIED) {
if (*slot) {
os_atomic_inc(&compressor_ro_uncompressed_skip_returned, relaxed);
return retval;
} else {
retval = vm_uncompressed_put(pn, slot);
if (retval == KERN_SUCCESS) {
os_atomic_inc(&compressor_ro_uncompressed_put, relaxed);
return retval;
}
}
}
#endif /* CONFIG_TRACK_UNMODIFIED_ANON_PAGES */
/* get the address of the page in the physical apperture in the kernel task virtual memory */
src = pmap_map_compressor_page(pn); /* XXX HERE JOE this needs to map with MTE */
assert(src != NULL);
retval = c_compress_page(src, (c_slot_mapping_t)slot, (c_segment_t *)current_chead, scratch_buf,
flags);
pmap_unmap_compressor_page(pn, src);
return retval;
}
void
vm_compressor_transfer(
int *dst_slot_p,
int *src_slot_p)
{
c_slot_mapping_t dst_slot, src_slot;
c_segment_t c_seg;
uint16_t c_indx;
c_slot_t cs;
src_slot = (c_slot_mapping_t) src_slot_p;
if (src_slot->s_cseg == C_SV_CSEG_ID || !vm_compressor_is_slot_compressed(src_slot_p)) {
*dst_slot_p = *src_slot_p;
*src_slot_p = 0;
return;
}
dst_slot = (c_slot_mapping_t) dst_slot_p;
Retry:
PAGE_REPLACEMENT_DISALLOWED(TRUE);
/* get segment for src_slot */
c_seg = c_segments[src_slot->s_cseg - 1].c_seg;
/* lock segment */
lck_mtx_lock_spin_always(&c_seg->c_lock);
/* wait if it's busy */
if (c_seg->c_busy && !c_seg->c_busy_swapping) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
c_seg_wait_on_busy(c_seg);
goto Retry;
}
/* find the c_slot */
c_indx = src_slot->s_cindx;
cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
/* point the c_slot back to dst_slot instead of src_slot */
C_SLOT_ASSERT_PACKABLE(dst_slot);
cs->c_packed_ptr = C_SLOT_PACK_PTR(dst_slot);
/* transfer */
*dst_slot_p = *src_slot_p;
*src_slot_p = 0;
lck_mtx_unlock_always(&c_seg->c_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
#if defined(__arm64__)
extern uint64_t vm_swapfile_last_failed_to_create_ts;
__attribute__((noreturn))
void
vm_panic_hibernate_write_image_failed(int err)
{
panic("hibernate_write_image encountered error 0x%x - %u, %u, %d, %d, %d, %d, %d, %d, %d, %d, %llu, %d, %d, %d\n",
err,
VM_PAGE_COMPRESSOR_COUNT, vm_page_wire_count,
c_age_count, c_major_count, c_minor_count, (c_early_swapout_count + c_regular_swapout_count + c_late_swapout_count), c_swappedout_sparse_count,
vm_num_swap_files, vm_num_pinned_swap_files, vm_swappin_enabled, vm_swap_put_failures,
(vm_swapfile_last_failed_to_create_ts ? 1:0), hibernate_no_swapspace, hibernate_flush_timed_out);
}
#endif /*(__arm64__)*/
#if CONFIG_FREEZE
int freezer_finished_filling = 0;
void
vm_compressor_finished_filling(
void **current_chead)
{
c_segment_t c_seg;
if ((c_seg = *(c_segment_t *)current_chead) == NULL) {
return;
}
assert(c_seg->c_state == C_IS_FILLING);
lck_mtx_lock_spin_always(&c_seg->c_lock);
c_current_seg_filled(c_seg, (c_segment_t *)current_chead);
lck_mtx_unlock_always(&c_seg->c_lock);
freezer_finished_filling++;
}
/*
* This routine is used to transfer the compressed chunks from
* the c_seg/cindx pointed to by slot_p into a new c_seg headed
* by the current_chead and a new cindx within that c_seg.
*
* Currently, this routine is only used by the "freezer backed by
* compressor with swap" mode to create a series of c_segs that
* only contain compressed data belonging to one task. So, we
* move a task's previously compressed data into a set of new
* c_segs which will also hold the task's yet to be compressed data.
*/
kern_return_t
vm_compressor_relocate(
void **current_chead,
int *slot_p)
{
c_slot_mapping_t slot_ptr;
c_slot_mapping_t src_slot;
uint32_t c_rounded_size;
uint32_t c_size;
uint16_t dst_slot;
c_slot_t c_dst;
c_slot_t c_src;
uint16_t c_indx;
c_segment_t c_seg_dst = NULL;
c_segment_t c_seg_src = NULL;
kern_return_t kr = KERN_SUCCESS;
src_slot = (c_slot_mapping_t) slot_p;
if (src_slot->s_cseg == C_SV_CSEG_ID) {
/*
* no need to relocate... this is a page full of a single
* value which is hashed to a single entry not contained
* in a c_segment_t
*/
return kr;
}
if (vm_compressor_is_slot_compressed((int *)src_slot) == false) {
/*
* Unmodified anonymous pages are sitting uncompressed on disk.
* So don't pull them back in again.
*/
return kr;
}
Relookup_dst:
c_seg_dst = c_seg_allocate((c_segment_t *)current_chead);
/*
* returns with c_seg lock held
* and PAGE_REPLACEMENT_DISALLOWED(TRUE)...
* c_nextslot has been allocated and
* c_store.c_buffer populated
*/
if (c_seg_dst == NULL) {
/*
* Out of compression segments?
*/
kr = KERN_RESOURCE_SHORTAGE;
goto out;
}
assert(c_seg_dst->c_busy == 0);
C_SEG_BUSY(c_seg_dst);
dst_slot = c_seg_dst->c_nextslot;
lck_mtx_unlock_always(&c_seg_dst->c_lock);
Relookup_src:
c_seg_src = c_segments[src_slot->s_cseg - 1].c_seg;
assert(c_seg_dst != c_seg_src);
lck_mtx_lock_spin_always(&c_seg_src->c_lock);
if (C_SEG_IS_ON_DISK_OR_SOQ(c_seg_src) ||
c_seg_src->c_state == C_IS_FILLING) {
/*
* Skip this page if :-
* a) the src c_seg is already on-disk (or on its way there)
* A "thaw" can mark a process as eligible for
* another freeze cycle without bringing any of
* its swapped out c_segs back from disk (because
* that is done on-demand).
* Or, this page may be mapped elsewhere in the task's map,
* and we may have marked it for swap already.
*
* b) Or, the src c_seg is being filled by the compressor
* thread. We don't want the added latency of waiting for
* this c_seg in the freeze path and so we skip it.
*/
PAGE_REPLACEMENT_DISALLOWED(FALSE);
lck_mtx_unlock_always(&c_seg_src->c_lock);
c_seg_src = NULL;
goto out;
}
if (c_seg_src->c_busy) {
PAGE_REPLACEMENT_DISALLOWED(FALSE);
c_seg_wait_on_busy(c_seg_src);
c_seg_src = NULL;
PAGE_REPLACEMENT_DISALLOWED(TRUE);
goto Relookup_src;
}
C_SEG_BUSY(c_seg_src);
lck_mtx_unlock_always(&c_seg_src->c_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
/* find the c_slot */
c_indx = src_slot->s_cindx;
c_src = C_SEG_SLOT_FROM_INDEX(c_seg_src, c_indx);
c_size = UNPACK_C_SIZE(c_src);
assert(c_size);
int combined_size;
combined_size = c_size;
if (combined_size > (uint32_t)(c_seg_bufsize - C_SEG_OFFSET_TO_BYTES((int32_t)c_seg_dst->c_nextoffset))) {
/*
* This segment is full. We need a new one.
*/
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg_src->c_lock);
C_SEG_WAKEUP_DONE(c_seg_src);
lck_mtx_unlock_always(&c_seg_src->c_lock);
c_seg_src = NULL;
lck_mtx_lock_spin_always(&c_seg_dst->c_lock);
assert(c_seg_dst->c_busy);
assert(c_seg_dst->c_state == C_IS_FILLING);
assert(!c_seg_dst->c_on_minorcompact_q);
c_current_seg_filled(c_seg_dst, (c_segment_t *)current_chead);
assert(*current_chead == NULL);
C_SEG_WAKEUP_DONE(c_seg_dst);
lck_mtx_unlock_always(&c_seg_dst->c_lock);
c_seg_dst = NULL;
PAGE_REPLACEMENT_DISALLOWED(FALSE);
goto Relookup_dst;
}
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg_dst, c_seg_dst->c_nextslot);
memcpy(&c_seg_dst->c_store.c_buffer[c_seg_dst->c_nextoffset], &c_seg_src->c_store.c_buffer[c_src->c_offset], combined_size);
/*
* Is platform alignment actually necessary since wkdm aligns its output?
*/
c_rounded_size = (combined_size + C_SEG_OFFSET_ALIGNMENT_MASK) & ~C_SEG_OFFSET_ALIGNMENT_MASK;
cslot_copy(c_dst, c_src);
c_dst->c_offset = c_seg_dst->c_nextoffset;
if (c_seg_dst->c_firstemptyslot == c_seg_dst->c_nextslot) {
c_seg_dst->c_firstemptyslot++;
}
c_seg_dst->c_slots_used++;
c_seg_dst->c_nextslot++;
c_seg_dst->c_bytes_used += c_rounded_size;
c_seg_dst->c_nextoffset += C_SEG_BYTES_TO_OFFSET(c_rounded_size);
PACK_C_SIZE(c_src, 0);
c_seg_src->c_bytes_used -= c_rounded_size;
c_seg_src->c_bytes_unused += c_rounded_size;
assert(c_seg_src->c_slots_used);
c_seg_src->c_slots_used--;
if (!c_seg_src->c_swappedin) {
/* Pessimistically lose swappedin status when non-swappedin pages are added. */
c_seg_dst->c_swappedin = false;
}
if (c_indx < c_seg_src->c_firstemptyslot) {
c_seg_src->c_firstemptyslot = c_indx;
}
c_dst = C_SEG_SLOT_FROM_INDEX(c_seg_dst, dst_slot);
PAGE_REPLACEMENT_ALLOWED(TRUE);
slot_ptr = C_SLOT_UNPACK_PTR(c_dst);
/* <csegno=0,indx=0> would mean "empty slot", so use csegno+1 */
slot_ptr->s_cseg = c_seg_dst->c_mysegno + 1;
slot_ptr->s_cindx = dst_slot;
PAGE_REPLACEMENT_ALLOWED(FALSE);
out:
if (c_seg_src) {
lck_mtx_lock_spin_always(&c_seg_src->c_lock);
C_SEG_WAKEUP_DONE(c_seg_src);
if (c_seg_src->c_bytes_used == 0 && c_seg_src->c_state != C_IS_FILLING) {
if (!c_seg_src->c_on_minorcompact_q) {
c_seg_need_delayed_compaction(c_seg_src, FALSE);
}
}
lck_mtx_unlock_always(&c_seg_src->c_lock);
}
if (c_seg_dst) {
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg_dst->c_lock);
if (c_seg_dst->c_nextoffset >= c_seg_off_limit || c_seg_dst->c_nextslot >= C_SLOT_MAX_INDEX) {
/*
* Nearing or exceeded maximum slot and offset capacity.
*/
assert(c_seg_dst->c_busy);
assert(c_seg_dst->c_state == C_IS_FILLING);
assert(!c_seg_dst->c_on_minorcompact_q);
c_current_seg_filled(c_seg_dst, (c_segment_t *)current_chead);
assert(*current_chead == NULL);
}
C_SEG_WAKEUP_DONE(c_seg_dst);
lck_mtx_unlock_always(&c_seg_dst->c_lock);
c_seg_dst = NULL;
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
return kr;
}
#endif /* CONFIG_FREEZE */
#if DEVELOPMENT || DEBUG
void
vm_compressor_inject_error(int *slot)
{
c_slot_mapping_t slot_ptr = (c_slot_mapping_t)slot;
/* No error detection for single-value compression. */
if (slot_ptr->s_cseg == C_SV_CSEG_ID) {
printf("%s(): cannot inject errors in SV-compressed pages\n", __func__ );
return;
}
/* s_cseg is actually "segno+1" */
const uint32_t c_segno = slot_ptr->s_cseg - 1;
assert(c_segno < c_segments_available);
assert(c_segments[c_segno].c_segno >= c_segments_available);
const c_segment_t c_seg = c_segments[c_segno].c_seg;
PAGE_REPLACEMENT_DISALLOWED(TRUE);
lck_mtx_lock_spin_always(&c_seg->c_lock);
assert(c_seg->c_state != C_IS_EMPTY && c_seg->c_state != C_IS_FREE);
const uint16_t c_indx = slot_ptr->s_cindx;
assert(c_indx < c_seg->c_nextslot);
/*
* To safely make this segment temporarily writable, we need to mark
* the segment busy, which allows us to release the segment lock.
*/
while (c_seg->c_busy) {
c_seg_wait_on_busy(c_seg);
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
C_SEG_BUSY(c_seg);
bool already_writable = (c_seg->c_state == C_IS_FILLING);
if (!already_writable) {
/*
* Protection update must be performed preemptibly, so temporarily drop
* the lock. Having set c_busy will prevent most other concurrent
* operations.
*/
lck_mtx_unlock_always(&c_seg->c_lock);
C_SEG_MAKE_WRITEABLE(c_seg);
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
/*
* Once we've released the lock following our c_state == C_IS_FILLING check,
* c_current_seg_filled() can (re-)write-protect the segment. However, it
* will transition from C_IS_FILLING before releasing the c_seg lock, so we
* can detect this by re-checking after we've reobtained the lock.
*/
if (already_writable && c_seg->c_state != C_IS_FILLING) {
lck_mtx_unlock_always(&c_seg->c_lock);
C_SEG_MAKE_WRITEABLE(c_seg);
lck_mtx_lock_spin_always(&c_seg->c_lock);
already_writable = false;
/* Segment can't be freed while c_busy is set. */
assert(c_seg->c_state != C_IS_FILLING);
}
/*
* Skip if the segment is on disk. This check can only be performed after
* the final acquisition of the segment lock before we attempt to write to
* the segment.
*/
if (!C_SEG_IS_ON_DISK_OR_SOQ(c_seg)) {
c_slot_t cs = C_SEG_SLOT_FROM_INDEX(c_seg, c_indx);
int32_t *data = &c_seg->c_store.c_buffer[cs->c_offset];
/* assume that the compressed data holds at least one int32_t */
assert(UNPACK_C_SIZE(cs) > sizeof(*data));
/*
* This bit is known to be in the payload of a MISS packet resulting from
* the pattern used in the test pattern from decompression_failure.c.
* Flipping it should result in many corrupted bits in the test page.
*/
data[0] ^= 0x00000100;
}
if (!already_writable) {
lck_mtx_unlock_always(&c_seg->c_lock);
C_SEG_WRITE_PROTECT(c_seg);
lck_mtx_lock_spin_always(&c_seg->c_lock);
}
C_SEG_WAKEUP_DONE(c_seg);
lck_mtx_unlock_always(&c_seg->c_lock);
PAGE_REPLACEMENT_DISALLOWED(FALSE);
}
/*
* Serialize information about a specific segment
* returns true if the segment was written or there's nothing to write for the segno
* false if there's not enough space
* argument size input - the size of the input buffer, output - the size written, set to 0 on failure
*/
kern_return_t
vm_compressor_serialize_segment_debug_info(int segno, char *buf, size_t *size)
{
size_t insize = *size;
size_t offset = 0;
*size = 0;
if (c_segments[segno].c_segno < c_segments_available) {
/* This check means there's no pointer assigned here so it must be an index in the free list.
* if this was an active c_segment, .c_seg would be assigned to, which is a pointer, interpreted as an int it
* would be higher than c_segments_available. See also assert to this effect right after assigning to c_seg in
* c_seg_allocate()
*/
return KERN_SUCCESS;
}
if (c_segments[segno].c_segno == (uint32_t)-1) {
/* c_segno of the end of the free-list */
return KERN_SUCCESS;
}
const struct c_segment* c_seg = c_segments[segno].c_seg;
if (c_seg->c_state == C_IS_FREE) {
return KERN_SUCCESS; /* nothing needs to be done */
}
int nslots = c_seg->c_nextslot;
/* do we have enough space? */
if (sizeof(struct c_segment_info) + (nslots * sizeof(struct c_slot_info)) > insize) {
return KERN_NO_SPACE; /* not enough space, please call me again */
}
struct c_segment_info* csi = (struct c_segment_info*)buf;
offset += sizeof(struct c_segment_info);
csi->csi_mysegno = c_seg->c_mysegno;
csi->csi_creation_ts = c_seg->c_creation_ts;
csi->csi_swappedin_ts = c_seg->c_swappedin_ts;
csi->csi_bytes_unused = c_seg->c_bytes_unused;
csi->csi_bytes_used = c_seg->c_bytes_used;
csi->csi_populated_offset = c_seg->c_populated_offset;
csi->csi_state = c_seg->c_state;
csi->csi_swappedin = c_seg->c_swappedin;
csi->csi_on_minor_compact_q = c_seg->c_on_minorcompact_q;
csi->csi_has_donated_pages = c_seg->c_has_donated_pages;
csi->csi_slots_used = (uint16_t)c_seg->c_slots_used;
csi->csi_slot_var_array_len = c_seg->c_slot_var_array_len;
csi->csi_slots_len = (uint16_t)nslots;
#if TRACK_C_SEGMENT_UTILIZATION
csi->csi_decompressions_since_swapin = c_seg->c_decompressions_since_swapin;
#else
csi->csi_decompressions_since_swapin = 0;
#endif /* TRACK_C_SEGMENT_UTILIZATION */
for (int si = 0; si < nslots; ++si) {
/* see also c_seg_validate() for some of the details */
const struct c_slot* cs = C_SEG_SLOT_FROM_INDEX(c_seg, si);
struct c_slot_info* ssi = (struct c_slot_info*)(buf + offset);
ssi->csi_size = UNPACK_C_SIZE(cs);
offset += sizeof(struct c_slot_info);
}
*size = offset;
return KERN_SUCCESS;
}
#endif /* DEVELOPMENT || DEBUG */
#if CONFIG_TRACK_UNMODIFIED_ANON_PAGES
struct vnode;
extern void vm_swapfile_open(const char *path, struct vnode **vp);
extern int vm_swapfile_preallocate(struct vnode *vp, uint64_t *size, boolean_t *pin);
struct vnode *uncompressed_vp0 = NULL;
struct vnode *uncompressed_vp1 = NULL;
uint32_t uncompressed_file0_free_pages = 0, uncompressed_file1_free_pages = 0;
uint64_t uncompressed_file0_free_offset = 0, uncompressed_file1_free_offset = 0;
uint64_t compressor_ro_uncompressed = 0;
uint64_t compressor_ro_uncompressed_total_returned = 0;
uint64_t compressor_ro_uncompressed_skip_returned = 0;
uint64_t compressor_ro_uncompressed_get = 0;
uint64_t compressor_ro_uncompressed_put = 0;
uint64_t compressor_ro_uncompressed_swap_usage = 0;
extern void vnode_put(struct vnode* vp);
extern int vnode_getwithref(struct vnode* vp);
extern int vm_swapfile_io(struct vnode *vp, uint64_t offset, uint64_t start, int npages, int flags, void *upl_ctx);
#define MAX_OFFSET_PAGES (255)
uint64_t uncompressed_file0_space_bitmap[MAX_OFFSET_PAGES];
uint64_t uncompressed_file1_space_bitmap[MAX_OFFSET_PAGES];
#define UNCOMPRESSED_FILEIDX_OFFSET_MASK (((uint32_t)1<<31ull) - 1)
#define UNCOMPRESSED_FILEIDX_SHIFT (29)
#define UNCOMPRESSED_FILEIDX_MASK (3)
#define UNCOMPRESSED_OFFSET_SHIFT (29)
#define UNCOMPRESSED_OFFSET_MASK (7)
static uint32_t
vm_uncompressed_extract_swap_file(int slot)
{
uint32_t fileidx = (((uint32_t)slot & UNCOMPRESSED_FILEIDX_OFFSET_MASK) >> UNCOMPRESSED_FILEIDX_SHIFT) & UNCOMPRESSED_FILEIDX_MASK;
return fileidx;
}
static uint32_t
vm_uncompressed_extract_swap_offset(int slot)
{
return slot & (uint32_t)(~(UNCOMPRESSED_OFFSET_MASK << UNCOMPRESSED_OFFSET_SHIFT));
}
static void
vm_uncompressed_return_space_to_swap(int slot)
{
PAGE_REPLACEMENT_ALLOWED(TRUE);
uint32_t fileidx = vm_uncompressed_extract_swap_file(slot);
if (fileidx == 1) {
uint32_t free_offset = vm_uncompressed_extract_swap_offset(slot);
uint64_t pgidx = free_offset / PAGE_SIZE_64;
uint64_t chunkidx = pgidx / 64;
uint64_t chunkoffset = pgidx % 64;
#if DEVELOPMENT || DEBUG
uint64_t vaddr = (uint64_t)&uncompressed_file0_space_bitmap[chunkidx];
uint64_t maxvaddr = (uint64_t)&uncompressed_file0_space_bitmap[MAX_OFFSET_PAGES];
assertf(vaddr < maxvaddr, "0x%llx 0x%llx", vaddr, maxvaddr);
#endif /*DEVELOPMENT || DEBUG*/
assertf((uncompressed_file0_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)),
"0x%x %llu %llu", slot, chunkidx, chunkoffset);
uncompressed_file0_space_bitmap[chunkidx] &= ~((uint64_t)1 << chunkoffset);
assertf(!(uncompressed_file0_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)),
"0x%x %llu %llu", slot, chunkidx, chunkoffset);
uncompressed_file0_free_pages++;
} else {
uint32_t free_offset = vm_uncompressed_extract_swap_offset(slot);
uint64_t pgidx = free_offset / PAGE_SIZE_64;
uint64_t chunkidx = pgidx / 64;
uint64_t chunkoffset = pgidx % 64;
assertf((uncompressed_file1_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)),
"%llu %llu", chunkidx, chunkoffset);
uncompressed_file1_space_bitmap[chunkidx] &= ~((uint64_t)1 << chunkoffset);
uncompressed_file1_free_pages++;
}
compressor_ro_uncompressed_swap_usage--;
PAGE_REPLACEMENT_ALLOWED(FALSE);
}
static int
vm_uncompressed_reserve_space_in_swap()
{
int slot = 0;
if (uncompressed_file0_free_pages == 0 && uncompressed_file1_free_pages == 0) {
return -1;
}
PAGE_REPLACEMENT_ALLOWED(TRUE);
if (uncompressed_file0_free_pages) {
uint64_t chunkidx = 0;
uint64_t chunkoffset = 0;
while (uncompressed_file0_space_bitmap[chunkidx] == 0xffffffffffffffff) {
chunkidx++;
}
while (uncompressed_file0_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)) {
chunkoffset++;
}
assertf((uncompressed_file0_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)) == 0,
"%llu %llu", chunkidx, chunkoffset);
#if DEVELOPMENT || DEBUG
uint64_t vaddr = (uint64_t)&uncompressed_file0_space_bitmap[chunkidx];
uint64_t maxvaddr = (uint64_t)&uncompressed_file0_space_bitmap[MAX_OFFSET_PAGES];
assertf(vaddr < maxvaddr, "0x%llx 0x%llx", vaddr, maxvaddr);
#endif /*DEVELOPMENT || DEBUG*/
uncompressed_file0_space_bitmap[chunkidx] |= ((uint64_t)1 << chunkoffset);
uncompressed_file0_free_offset = ((chunkidx * 64) + chunkoffset) * PAGE_SIZE_64;
assertf((uncompressed_file0_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)),
"%llu %llu", chunkidx, chunkoffset);
assert(uncompressed_file0_free_offset <= (1 << UNCOMPRESSED_OFFSET_SHIFT));
slot = (int)((1 << UNCOMPRESSED_FILEIDX_SHIFT) + uncompressed_file0_free_offset);
uncompressed_file0_free_pages--;
} else {
uint64_t chunkidx = 0;
uint64_t chunkoffset = 0;
while (uncompressed_file1_space_bitmap[chunkidx] == 0xFFFFFFFFFFFFFFFF) {
chunkidx++;
}
while (uncompressed_file1_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)) {
chunkoffset++;
}
assert((uncompressed_file1_space_bitmap[chunkidx] & ((uint64_t)1 << chunkoffset)) == 0);
uncompressed_file1_space_bitmap[chunkidx] |= ((uint64_t)1 << chunkoffset);
uncompressed_file1_free_offset = ((chunkidx * 64) + chunkoffset) * PAGE_SIZE_64;
slot = (int)((2 << UNCOMPRESSED_FILEIDX_SHIFT) + uncompressed_file1_free_offset);
uncompressed_file1_free_pages--;
}
compressor_ro_uncompressed_swap_usage++;
PAGE_REPLACEMENT_ALLOWED(FALSE);
return slot;
}
#define MAX_IO_REQ (16)
struct _uncompressor_io_req {
uint64_t addr;
bool inuse;
} uncompressor_io_req[MAX_IO_REQ];
int
vm_uncompressed_put(ppnum_t pn, int *slot)
{
int retval = 0;
struct vnode *uncompressed_vp = NULL;
uint64_t uncompress_offset = 0;
again:
if (uncompressed_vp0 == NULL) {
PAGE_REPLACEMENT_ALLOWED(TRUE);
if (uncompressed_vp0 == NULL) {
uint64_t size = (MAX_OFFSET_PAGES * 1024 * 1024ULL);
vm_swapfile_open("/private/var/vm/uncompressedswap0", &uncompressed_vp0);
if (uncompressed_vp0 == NULL) {
PAGE_REPLACEMENT_ALLOWED(FALSE);
return KERN_NO_ACCESS;
}
vm_swapfile_preallocate(uncompressed_vp0, &size, NULL);
uncompressed_file0_free_pages = (uint32_t)atop(size);
bzero(uncompressed_file0_space_bitmap, sizeof(uint64_t) * MAX_OFFSET_PAGES);
int i = 0;
for (; i < MAX_IO_REQ; i++) {
kmem_alloc(kernel_map, (vm_offset_t*)&uncompressor_io_req[i].addr, PAGE_SIZE_64, KMA_NOFAIL | KMA_KOBJECT, VM_KERN_MEMORY_COMPRESSOR);
uncompressor_io_req[i].inuse = false;
}
vm_swapfile_open("/private/var/vm/uncompressedswap1", &uncompressed_vp1);
assert(uncompressed_vp1);
vm_swapfile_preallocate(uncompressed_vp1, &size, NULL);
uncompressed_file1_free_pages = (uint32_t)atop(size);
bzero(uncompressed_file1_space_bitmap, sizeof(uint64_t) * MAX_OFFSET_PAGES);
PAGE_REPLACEMENT_ALLOWED(FALSE);
} else {
PAGE_REPLACEMENT_ALLOWED(FALSE);
delay(100);
goto again;
}
}
int swapinfo = vm_uncompressed_reserve_space_in_swap();
if (swapinfo == -1) {
*slot = 0;
return KERN_RESOURCE_SHORTAGE;
}
if (vm_uncompressed_extract_swap_file(swapinfo) == 1) {
uncompressed_vp = uncompressed_vp0;
} else {
uncompressed_vp = uncompressed_vp1;
}
uncompress_offset = vm_uncompressed_extract_swap_offset(swapinfo);
if ((retval = vnode_getwithref(uncompressed_vp)) != 0) {
os_log_error_with_startup_serial(OS_LOG_DEFAULT, "vm_uncompressed_put: vnode_getwithref on swapfile failed with %d\n", retval);
} else {
int i = 0;
retry:
PAGE_REPLACEMENT_ALLOWED(TRUE);
for (i = 0; i < MAX_IO_REQ; i++) {
if (uncompressor_io_req[i].inuse == false) {
uncompressor_io_req[i].inuse = true;
break;
}
}
if (i == MAX_IO_REQ) {
assert_wait((event_t)&uncompressor_io_req, THREAD_UNINT);
PAGE_REPLACEMENT_ALLOWED(FALSE);
thread_block(THREAD_CONTINUE_NULL);
goto retry;
}
PAGE_REPLACEMENT_ALLOWED(FALSE);
void *addr = pmap_map_compressor_page(pn);
memcpy((void*)uncompressor_io_req[i].addr, addr, PAGE_SIZE_64);
pmap_unmap_compressor_page(pn, addr);
retval = vm_swapfile_io(uncompressed_vp, uncompress_offset, (uint64_t)uncompressor_io_req[i].addr, 1, SWAP_WRITE, NULL);
if (retval) {
*slot = 0;
} else {
*slot = (int)swapinfo;
((c_slot_mapping_t)(slot))->s_uncompressed = 1;
}
vnode_put(uncompressed_vp);
PAGE_REPLACEMENT_ALLOWED(TRUE);
uncompressor_io_req[i].inuse = false;
thread_wakeup((event_t)&uncompressor_io_req);
PAGE_REPLACEMENT_ALLOWED(FALSE);
}
return retval;
}
int
vm_uncompressed_get(ppnum_t pn, int *slot, __unused vm_compressor_options_t flags)
{
int retval = 0;
struct vnode *uncompressed_vp = NULL;
uint32_t fileidx = vm_uncompressed_extract_swap_file(*slot);
uint64_t uncompress_offset = vm_uncompressed_extract_swap_offset(*slot);
if (__improbable(flags & C_KDP)) {
return -2;
}
if (fileidx == 1) {
uncompressed_vp = uncompressed_vp0;
} else {
uncompressed_vp = uncompressed_vp1;
}
if ((retval = vnode_getwithref(uncompressed_vp)) != 0) {
os_log_error_with_startup_serial(OS_LOG_DEFAULT, "vm_uncompressed_put: vnode_getwithref on swapfile failed with %d\n", retval);
} else {
int i = 0;
retry:
PAGE_REPLACEMENT_ALLOWED(TRUE);
for (i = 0; i < MAX_IO_REQ; i++) {
if (uncompressor_io_req[i].inuse == false) {
uncompressor_io_req[i].inuse = true;
break;
}
}
if (i == MAX_IO_REQ) {
assert_wait((event_t)&uncompressor_io_req, THREAD_UNINT);
PAGE_REPLACEMENT_ALLOWED(FALSE);
thread_block(THREAD_CONTINUE_NULL);
goto retry;
}
PAGE_REPLACEMENT_ALLOWED(FALSE);
retval = vm_swapfile_io(uncompressed_vp, uncompress_offset, (uint64_t)uncompressor_io_req[i].addr, 1, SWAP_READ, NULL);
vnode_put(uncompressed_vp);
void *addr = pmap_map_compressor_page(pn);
memcpy(addr, (void*)uncompressor_io_req[i].addr, PAGE_SIZE_64);
pmap_unmap_compressor_page(pn, addr);
PAGE_REPLACEMENT_ALLOWED(TRUE);
uncompressor_io_req[i].inuse = false;
thread_wakeup((event_t)&uncompressor_io_req);
PAGE_REPLACEMENT_ALLOWED(FALSE);
}
return retval;
}
int
vm_uncompressed_free(int *slot, __unused vm_compressor_options_t flags)
{
vm_uncompressed_return_space_to_swap(*slot);
*slot = 0;
return 0;
}
#endif /*CONFIG_TRACK_UNMODIFIED_ANON_PAGES*/