/**
* add_to_swap - allocate swap space for a page
* @page: page we want to move to swap
*
* Allocate swap space for the page and add the page to the
* swap cache. Caller needs to hold the page lock.
*/
int add_to_swap(struct page *page)
{
swp_entry_t entry;
int err;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(!PageUptodate(page));
#ifdef CONFIG_HSWAP
if (!current_is_kswapd())
entry = get_lowest_prio_swap_page();
else
#endif
entry = get_swap_page();
if (!entry.val)
return 0;
if (unlikely(PageTransHuge(page)))
if (unlikely(split_huge_page(page))) {
swapcache_free(entry, NULL);
return 0;
}
/*
* Radix-tree node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
* TODO: this could cause a theoretical memory reclaim
* deadlock in the swap out path.
*/
/*
* Add it to the swap cache and mark it dirty
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
if (!err) { /* Success */
SetPageDirty(page);
return 1;
} else { /* -ENOMEM radix-tree allocation failure */
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
* clear SWAP_HAS_CACHE flag.
*/
swapcache_free(entry, NULL);
return 0;
}
}
void tune_lmk_param(int *other_free, int *other_file, struct shrink_control *sc)
{
gfp_t gfp_mask;
struct zone *preferred_zone;
struct zonelist *zonelist;
enum zone_type high_zoneidx, classzone_idx;
unsigned long balance_gap;
gfp_mask = sc->gfp_mask;
zonelist = node_zonelist(0, gfp_mask);
high_zoneidx = gfp_zone(gfp_mask);
first_zones_zonelist(zonelist, high_zoneidx, NULL, &preferred_zone);
classzone_idx = zone_idx(preferred_zone);
balance_gap = min(low_wmark_pages(preferred_zone),
(preferred_zone->present_pages +
KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
KSWAPD_ZONE_BALANCE_GAP_RATIO);
if (likely(current_is_kswapd() && zone_watermark_ok(preferred_zone, 0,
high_wmark_pages(preferred_zone) + SWAP_CLUSTER_MAX +
balance_gap, 0, 0))) {
if (lmk_fast_run)
tune_lmk_zone_param(zonelist, classzone_idx, other_free,
other_file);
else
tune_lmk_zone_param(zonelist, classzone_idx, other_free,
NULL);
if (zone_watermark_ok(preferred_zone, 0, 0, ZONE_HIGHMEM, 0))
*other_free -=
preferred_zone->lowmem_reserve[ZONE_HIGHMEM];
else
*other_free -= zone_page_state(preferred_zone,
NR_FREE_PAGES);
lowmem_print(4, "lowmem_shrink of kswapd tunning for highmem "
"ofree %d, %d\n", *other_free, *other_file);
} else {
tune_lmk_zone_param(zonelist, classzone_idx, other_free,
other_file);
lowmem_print(4, "lowmem_shrink tunning for others ofree %d, "
"%d\n", *other_free, *other_file);
}
}
/*
* Attempt to release the private state associated with a page
* - Called if either PG_private or PG_fscache is set on the page
* - Caller holds page lock
* - Return true (may release page) or false (may not)
*/
static int nfs_release_page(struct page *page, gfp_t gfp)
{
struct address_space *mapping = page->mapping;
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
/* Only do I/O if gfp is a superset of GFP_KERNEL */
if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) {
int how = FLUSH_SYNC;
/* Don't let kswapd deadlock waiting for OOM RPC calls */
if (current_is_kswapd())
how = 0;
nfs_commit_inode(mapping->host, how);
}
/* If PagePrivate() is set, then the page is not freeable */
if (PagePrivate(page))
return 0;
return nfs_fscache_release_page(page, gfp);
}
static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
int rem = 0;
int tasksize;
int i;
int min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int selected_tasksize = 0;
int selected_oom_score_adj;
#ifdef CONFIG_SAMP_HOTNESS
int selected_hotness_adj = 0;
#endif
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free;
int other_file;
unsigned long nr_to_scan = sc->nr_to_scan;
#ifdef CONFIG_SEC_DEBUG_LMK_MEMINFO
static DEFINE_RATELIMIT_STATE(lmk_rs, DEFAULT_RATELIMIT_INTERVAL, 1);
#endif
unsigned long nr_cma_free;
struct reclaim_state *reclaim_state = current->reclaim_state;
#if defined(CONFIG_CMA_PAGE_COUNTING)
unsigned long nr_cma_inactive_file;
unsigned long nr_cma_active_file;
unsigned long cma_page_ratio;
bool is_active_high;
bool flag = 0;
#endif
if (nr_to_scan > 0) {
if (mutex_lock_interruptible(&scan_mutex) < 0)
return 0;
}
other_free = global_page_state(NR_FREE_PAGES);
nr_cma_free = global_page_state(NR_FREE_CMA_PAGES);
#ifdef CONFIG_ZSWAP
if (!current_is_kswapd() || sc->priority <= 6)
#endif
other_free -= nr_cma_free;
#if defined(CONFIG_CMA_PAGE_COUNTING)
nr_cma_inactive_file = global_page_state(NR_CMA_INACTIVE_FILE);
nr_cma_active_file = global_page_state(NR_CMA_ACTIVE_FILE);
cma_page_ratio = 100 * global_page_state(NR_CMA_INACTIVE_FILE) /
global_page_state(NR_INACTIVE_FILE);
is_active_high = (global_page_state(NR_ACTIVE_FILE) >
global_page_state(NR_INACTIVE_FILE)) ? 1 : 0;
#endif
other_file = global_page_state(NR_FILE_PAGES);
#if defined(CONFIG_CMA_PAGE_COUNTING) && defined(CONFIG_EXCLUDE_LRU_LIVING_IN_CMA)
if (get_nr_swap_pages() < SSWAP_LMK_THRESHOLD && cma_page_ratio >= CMA_PAGE_RATIO
&& !is_active_high) {
other_file = other_file - (nr_cma_inactive_file + nr_cma_active_file);
flag = 1;
}
#endif
if (global_page_state(NR_SHMEM) + total_swapcache_pages < other_file)
other_file -= global_page_state(NR_SHMEM) + total_swapcache_pages;
else
other_file = 0;
if (lowmem_adj_size < array_size)
array_size = lowmem_adj_size;
if (lowmem_minfree_size < array_size)
array_size = lowmem_minfree_size;
for (i = 0; i < array_size; i++) {
if (other_free < lowmem_minfree[i] &&
other_file < lowmem_minfree[i]) {
min_score_adj = lowmem_adj[i];
break;
}
}
if (nr_to_scan > 0)
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj);
rem = global_page_state(NR_ACTIVE_ANON) +
global_page_state(NR_ACTIVE_FILE) +
global_page_state(NR_INACTIVE_ANON) +
global_page_state(NR_INACTIVE_FILE);
if (nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
if (nr_to_scan > 0)
mutex_unlock(&scan_mutex);
return rem;
}
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
int oom_score_adj;
#ifdef CONFIG_SAMP_HOTNESS
int hotness_adj = 0;
#endif
if (tsk->flags & PF_KTHREAD)
continue;
/* if task no longer has any memory ignore it */
if (test_task_flag(tsk, TIF_MM_RELEASED))
continue;
if (time_before_eq(jiffies, lowmem_deathpending_timeout)) {
if (test_task_flag(tsk, TIF_MEMDIE)) {
rcu_read_unlock();
/* give the system time to free up the memory */
msleep_interruptible(20);
mutex_unlock(&scan_mutex);
return 0;
}
}
p = find_lock_task_mm(tsk);
if (!p)
continue;
oom_score_adj = p->signal->oom_score_adj;
if (oom_score_adj < min_score_adj) {
task_unlock(p);
continue;
}
tasksize = get_mm_rss(p->mm);
#if defined(CONFIG_ZSWAP)
if (atomic_read(&zswap_stored_pages)) {
lowmem_print(3, "shown tasksize : %d\n", tasksize);
tasksize += atomic_read(&zswap_pool_pages) * get_mm_counter(p->mm, MM_SWAPENTS)
/ atomic_read(&zswap_stored_pages);
lowmem_print(3, "real tasksize : %d\n", tasksize);
}
#endif
#ifdef CONFIG_SAMP_HOTNESS
hotness_adj = p->signal->hotness_adj;
#endif
task_unlock(p);
if (tasksize <= 0)
continue;
if (selected) {
#ifdef CONFIG_SAMP_HOTNESS
if (min_score_adj <= lowmem_adj[4]) {
#endif
if (oom_score_adj < selected_oom_score_adj)
continue;
if (oom_score_adj == selected_oom_score_adj &&
tasksize <= selected_tasksize)
continue;
#ifdef CONFIG_SAMP_HOTNESS
} else {
if (hotness_adj > selected_hotness_adj)
continue;
if (hotness_adj == selected_hotness_adj && tasksize <= selected_tasksize)
continue;
}
#endif
}
selected = p;
selected_tasksize = tasksize;
selected_oom_score_adj = oom_score_adj;
#ifdef CONFIG_SAMP_HOTNESS
selected_hotness_adj = hotness_adj;
#endif
lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n",
p->pid, p->comm, oom_score_adj, tasksize);
}
if (selected) {
#if defined(CONFIG_CMA_PAGE_COUNTING)
#ifdef CONFIG_SAMP_HOTNESS
lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d, "
"ofree %d, ofile %d(%c), is_kswapd %d - "
"cma_free %lu priority %d cma_i_file %lu cma_a_file %lu, hotness %d\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize,
other_free, other_file, flag ? '-' : '+',
!!current_is_kswapd(),
nr_cma_free, sc->priority,
nr_cma_inactive_file, nr_cma_active_file, selected_hotness_adj);
#else
lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d, "
"ofree %d, ofile %d(%c), is_kswapd %d - "
"cma_free %lu priority %d cma_i_file %lu cma_a_file %lu\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize,
other_free, other_file, flag ? '-' : '+',
!!current_is_kswapd(),
nr_cma_free, sc->priority,
nr_cma_inactive_file, nr_cma_active_file);
#endif
#else
#ifdef CONFIG_SAMP_HOTNESS
lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d, "
"free memory = %d, reclaimable memory = %d "
"is_kswapd %d cma_free %lu priority %d, hotness %d\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize,
other_free, other_file,
!!current_is_kswapd(),
nr_cma_free, sc->priority, selected_hotness_adj);
#else
lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d, "
"free memory = %d, reclaimable memory = %d "
"is_kswapd %d cma_free %lu priority %d\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize,
other_free, other_file,
!!current_is_kswapd(),
nr_cma_free, sc->priority);
#endif
#endif
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
rem -= selected_tasksize;
rcu_read_unlock();
#ifdef LMK_COUNT_READ
lmk_count++;
#endif
#ifdef CONFIG_SEC_DEBUG_LMK_MEMINFO
if ((selected_oom_score_adj < lowmem_adj[5]) && __ratelimit(&lmk_rs)) {
lowmem_print(1, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj);
show_mem(SHOW_MEM_FILTER_NODES);
dump_tasks_info();
}
#endif
/* give the system time to free up the memory */
msleep_interruptible(20);
if(reclaim_state)
reclaim_state->reclaimed_slab = selected_tasksize;
} else
rcu_read_unlock();
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
mutex_unlock(&scan_mutex);
return rem;
}
static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
int rem = 0;
int tasksize;
int i;
int min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int selected_tasksize = 0;
int selected_oom_score_adj;
int selected_oom_adj = 0;
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free;
int other_file;
int reserved_free = 0;
int cma_free = 0;
unsigned long nr_to_scan = sc->nr_to_scan;
struct zone *zone;
int use_cma = can_use_cma_pages(sc->gfp_mask);
if (nr_to_scan > 0) {
if (!mutex_trylock(&scan_mutex)) {
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd())) {
msleep_interruptible(lowmem_sleep_ms);
}
return 0;
}
}
for_each_zone(zone)
{
if (is_normal(zone))
reserved_free = zone->watermark[WMARK_MIN] + zone->lowmem_reserve[_ZONE];
cma_free += zone_page_state(zone, NR_FREE_CMA_PAGES);
}
other_free = global_page_state(NR_FREE_PAGES);
if (global_page_state(NR_SHMEM) + global_page_state(NR_MLOCK) + total_swapcache_pages <
global_page_state(NR_FILE_PAGES))
other_file = global_page_state(NR_FILE_PAGES) -
global_page_state(NR_SHMEM) -
global_page_state(NR_MLOCK) -
total_swapcache_pages;
else
other_file = 0;
if (lowmem_adj_size < array_size)
array_size = lowmem_adj_size;
if (lowmem_minfree_size < array_size)
array_size = lowmem_minfree_size;
for (i = 0; i < array_size; i++) {
if ((other_free - reserved_free - (use_cma ? 0 : cma_free)) < lowmem_minfree[i] &&
other_file < lowmem_minfree[i]) {
min_score_adj = lowmem_adj[i];
break;
}
}
if (nr_to_scan > 0)
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d, rfree %d\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj, reserved_free);
rem = global_page_state(NR_ACTIVE_ANON) +
global_page_state(NR_ACTIVE_FILE) +
global_page_state(NR_INACTIVE_ANON) +
global_page_state(NR_INACTIVE_FILE);
if (nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
if (nr_to_scan > 0)
mutex_unlock(&scan_mutex);
return rem;
}
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
int oom_score_adj;
if (tsk->flags & PF_KTHREAD)
continue;
if (test_task_flag(tsk, TIF_MM_RELEASED))
continue;
if (time_before_eq(jiffies, lowmem_deathpending_timeout)) {
if (test_task_flag(tsk, TIF_MEMDIE)) {
lowmem_print(2, "skipping , waiting for process %d (%s) dead\n",
tsk->pid, tsk->comm);
rcu_read_unlock();
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd())) {
msleep_interruptible(lowmem_sleep_ms);
}
mutex_unlock(&scan_mutex);
return 0;
}
}
p = find_lock_task_mm(tsk);
if (!p)
continue;
oom_score_adj = p->signal->oom_score_adj;
if (oom_score_adj < min_score_adj) {
task_unlock(p);
continue;
}
tasksize = get_mm_rss(p->mm);
task_unlock(p);
if (tasksize <= 0)
continue;
if (selected) {
if (oom_score_adj < selected_oom_score_adj)
continue;
if (oom_score_adj == selected_oom_score_adj &&
tasksize <= selected_tasksize)
continue;
}
selected = p;
selected_tasksize = tasksize;
selected_oom_score_adj = oom_score_adj;
selected_oom_adj = p->signal->oom_adj;
lowmem_print(2, "select %d (%s), oom_adj %d score_adj %d, size %d, to kill\n",
p->pid, p->comm, selected_oom_adj, oom_score_adj, tasksize);
}
if (selected) {
bool should_dump_meminfo = false;
lowmem_print(1, "[%s] send sigkill to %d (%s), oom_adj %d, score_adj %d,"
" min_score_adj %d, size %dK, free %dK, file %dK, "
" reserved_free %dK, cma_free %dK, use_cma %d\n",
current->comm, selected->pid, selected->comm,
selected_oom_adj, selected_oom_score_adj,
min_score_adj, selected_tasksize << 2,
other_free << 2, other_file << 2, reserved_free << 2, cma_free << 2, use_cma);
if (!current_is_kswapd() && current->reclaim_state)
current->reclaim_state->trigger_lmk++;
lowmem_deathpending_timeout = jiffies + HZ;
#ifdef CONFIG_ANDROID_LOW_MEMORY_KILLER_AUTODETECT_OOM_ADJ_VALUES
#define DUMP_INFO_OOM_SCORE_ADJ_THRESHOLD ((7 * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE)
if (selected_oom_score_adj < DUMP_INFO_OOM_SCORE_ADJ_THRESHOLD)
#else
if (selected->signal->oom_adj < 7)
#endif
should_dump_meminfo = true;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
rem -= selected_tasksize;
rcu_read_unlock();
if (should_dump_meminfo) {
show_meminfo();
dump_tasks();
}
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd()))
msleep_interruptible(lowmem_sleep_ms);
} else
rcu_read_unlock();
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
mutex_unlock(&scan_mutex);
return rem;
}
static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
int rem = 0;
int tasksize;
int i;
int min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int selected_tasksize = 0;
int selected_oom_score_adj;
int selected_oom_adj = 0;
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free;
int other_file;
int reserved_free = 0;
unsigned long nr_to_scan = sc->nr_to_scan;
int fork_boost = 0;
size_t *min_array;
struct zone *zone;
if (nr_to_scan > 0) {
if (!mutex_trylock(&scan_mutex)) {
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd())) {
msleep_interruptible(lowmem_sleep_ms);
}
return 0;
}
}
for_each_zone(zone)
{
if(is_normal(zone))
{
reserved_free = zone->watermark[WMARK_MIN] + zone->lowmem_reserve[_ZONE];
break;
}
}
other_free = global_page_state(NR_FREE_PAGES);
other_file = global_page_state(NR_FILE_PAGES) -
global_page_state(NR_SHMEM) - global_page_state(NR_MLOCK) ;
if (lowmem_fork_boost &&
time_before_eq(jiffies, lowmem_fork_boost_timeout)) {
for (i = 0; i < lowmem_minfree_size; i++)
minfree_tmp[i] = lowmem_minfree[i] + lowmem_fork_boost_minfree[i];
min_array = minfree_tmp;
}
else
min_array = lowmem_minfree;
if (lowmem_adj_size < array_size)
array_size = lowmem_adj_size;
if (lowmem_minfree_size < array_size)
array_size = lowmem_minfree_size;
for (i = 0; i < array_size; i++) {
if ((other_free - reserved_free) < min_array[i] &&
other_file < min_array[i]) {
min_score_adj = lowmem_adj[i];
fork_boost = lowmem_fork_boost_minfree[i];
break;
}
}
if (nr_to_scan > 0)
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d, rfree %d\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj, reserved_free);
rem = global_page_state(NR_ACTIVE_ANON) +
global_page_state(NR_ACTIVE_FILE) +
global_page_state(NR_INACTIVE_ANON) +
global_page_state(NR_INACTIVE_FILE);
if (nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
if (nr_to_scan > 0)
mutex_unlock(&scan_mutex);
return rem;
}
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
int oom_score_adj;
if (tsk->flags & PF_KTHREAD)
continue;
if (time_before_eq(jiffies, lowmem_deathpending_timeout)) {
if (test_task_flag(tsk, TIF_MEMDIE)) {
lowmem_print(2, "skipping , waiting for process %d (%s) dead\n",
tsk->pid, tsk->comm);
rcu_read_unlock();
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd())) {
msleep_interruptible(lowmem_sleep_ms);
}
mutex_unlock(&scan_mutex);
return 0;
}
}
p = find_lock_task_mm(tsk);
if (!p)
continue;
oom_score_adj = p->signal->oom_score_adj;
if (oom_score_adj < selected_oom_score_adj) {
task_unlock(p);
continue;
}
tasksize = get_mm_rss(p->mm);
task_unlock(p);
if (tasksize <= 0)
continue;
if (selected && oom_score_adj == selected_oom_score_adj &&
tasksize <= selected_tasksize)
continue;
selected = p;
selected_tasksize = tasksize;
selected_oom_score_adj = oom_score_adj;
selected_oom_adj = p->signal->oom_adj;
lowmem_print(2, "select %d (%s), oom_adj %d score_adj %d, size %d, to kill\n",
p->pid, p->comm, selected_oom_adj, oom_score_adj, tasksize);
}
if (selected) {
lowmem_print(1, "[%s] send sigkill to %d (%s), oom_adj %d, score_adj %d,"
" min_score_adj %d, size %dK, free %dK, file %dK, fork_boost %dK,"
" reserved_free %dK\n",
current->comm, selected->pid, selected->comm,
selected_oom_adj, selected_oom_score_adj,
min_score_adj, selected_tasksize << 2,
other_free << 2, other_file << 2, fork_boost << 2, reserved_free << 2);
lowmem_deathpending_timeout = jiffies + HZ;
if (selected_oom_adj < 7)
{
show_meminfo();
dump_tasks();
}
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
rem -= selected_tasksize;
rcu_read_unlock();
if (!(lowmem_only_kswapd_sleep && !current_is_kswapd())) {
msleep_interruptible(lowmem_sleep_ms);
}
}
else
rcu_read_unlock();
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
mutex_unlock(&scan_mutex);
return rem;
}
static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
int rem = 0;
int tasksize;
int i;
short min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int minfree = 0;
int selected_tasksize = 0;
short selected_oom_score_adj;
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free;
int other_file;
unsigned long nr_to_scan = sc->nr_to_scan;
#ifdef CONFIG_SEC_DEBUG_LMK_MEMINFO
static DEFINE_RATELIMIT_STATE(lmk_rs, DEFAULT_RATELIMIT_INTERVAL, 1);
#endif
unsigned long nr_cma_free;
if (nr_to_scan > 0) {
if (mutex_lock_interruptible(&scan_mutex) < 0)
return 0;
}
other_free = global_page_state(NR_FREE_PAGES);
nr_cma_free = global_page_state(NR_FREE_CMA_PAGES);
if (!current_is_kswapd() || sc->priority <= 6)
other_free -= nr_cma_free;
if (global_page_state(NR_SHMEM) + total_swapcache_pages() <
global_page_state(NR_FILE_PAGES))
other_file = global_page_state(NR_FILE_PAGES) -
global_page_state(NR_SHMEM) -
total_swapcache_pages();
else
other_file = 0;
if (lowmem_adj_size < array_size)
array_size = lowmem_adj_size;
if (lowmem_minfree_size < array_size)
array_size = lowmem_minfree_size;
for (i = 0; i < array_size; i++) {
minfree = lowmem_minfree[i];
if (other_free < minfree && other_file < minfree) {
min_score_adj = lowmem_adj[i];
break;
}
}
if (nr_to_scan > 0)
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj);
rem = global_page_state(NR_ACTIVE_ANON) +
global_page_state(NR_ACTIVE_FILE) +
global_page_state(NR_INACTIVE_ANON) +
global_page_state(NR_INACTIVE_FILE);
if (nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
if (nr_to_scan > 0)
mutex_unlock(&scan_mutex);
return rem;
}
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
short oom_score_adj;
if (tsk->flags & PF_KTHREAD ||
tsk->state & TASK_UNINTERRUPTIBLE)
continue;
/* if task no longer has any memory ignore it */
if (test_task_flag(tsk, TIF_MM_RELEASED))
continue;
if (time_before_eq(jiffies, lowmem_deathpending_timeout)) {
if (test_task_flag(tsk, TIF_MEMDIE)) {
rcu_read_unlock();
/* give the system time to free up the memory */
msleep_interruptible(20);
mutex_unlock(&scan_mutex);
return 0;
}
}
p = find_lock_task_mm(tsk);
if (!p)
continue;
oom_score_adj = p->signal->oom_score_adj;
if (oom_score_adj < min_score_adj) {
task_unlock(p);
continue;
}
tasksize = get_mm_rss(p->mm);
task_unlock(p);
if (tasksize <= 0)
continue;
if (selected) {
if (oom_score_adj < selected_oom_score_adj)
continue;
if (oom_score_adj == selected_oom_score_adj &&
tasksize <= selected_tasksize)
continue;
}
selected = p;
selected_tasksize = tasksize;
selected_oom_score_adj = oom_score_adj;
lowmem_print(3, "select '%s' (%d), adj %hd, size %d, to kill\n",
p->comm, p->pid, oom_score_adj, tasksize);
}
if (selected) {
lowmem_print(1, "Killing '%s' (%d), adj %hd,\n" \
" to free %ldkB on behalf of '%s' (%d) because\n" \
" cache %ldkB is below limit %ldkB for oom_score_adj %hd\n" \
" Free memory is %ldkB above reserved.\n" \
" is_kswapd %d priority %d\n" \
" Free CMA is %ldkB\n" \
" Total reserve is %ldkB\n" \
" Total free pages is %ldkB\n" \
" Total file cache is %ldkB\n" \
" Slab Reclaimable is %ldkB\n" \
" Slab UnReclaimable is %ldkB\n" \
" Total Slab is %ldkB\n" \
" GFP mask is 0x%x\n",
selected->comm, selected->pid,
selected_oom_score_adj,
selected_tasksize * (long)(PAGE_SIZE / 1024),
current->comm, current->pid,
other_file * (long)(PAGE_SIZE / 1024),
minfree * (long)(PAGE_SIZE / 1024),
min_score_adj,
other_free * (long)(PAGE_SIZE / 1024),
!!current_is_kswapd(),
sc->priority,
nr_cma_free *
(long)(PAGE_SIZE / 1024),
totalreserve_pages * (long)(PAGE_SIZE / 1024),
global_page_state(NR_FREE_PAGES) *
(long)(PAGE_SIZE / 1024),
global_page_state(NR_FILE_PAGES) *
(long)(PAGE_SIZE / 1024),
global_page_state(NR_SLAB_RECLAIMABLE) *
(long)(PAGE_SIZE / 1024),
global_page_state(NR_SLAB_UNRECLAIMABLE) *
(long)(PAGE_SIZE / 1024),
global_page_state(NR_SLAB_RECLAIMABLE) *
(long)(PAGE_SIZE / 1024) +
global_page_state(NR_SLAB_UNRECLAIMABLE) *
(long)(PAGE_SIZE / 1024),
sc->gfp_mask);
if (lowmem_debug_level >= 2 && selected_oom_score_adj == 0) {
show_mem(SHOW_MEM_FILTER_NODES);
dump_tasks(NULL, NULL);
show_mem_call_notifiers();
}
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
rem -= selected_tasksize;
rcu_read_unlock();
#ifdef LMK_COUNT_READ
lmk_count++;
#endif
#ifdef CONFIG_SEC_DEBUG_LMK_MEMINFO
if (__ratelimit(&lmk_rs)) {
lowmem_print(1, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n",
nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj);
show_mem(SHOW_MEM_FILTER_NODES);
dump_tasks_info();
}
#endif
/* give the system time to free up the memory */
msleep_interruptible(20);
} else
rcu_read_unlock();
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
nr_to_scan, sc->gfp_mask, rem);
mutex_unlock(&scan_mutex);
return rem;
}
