static int show_mem_notifier_get(void *dat, u64 *val)
{
show_mem_call_notifiers();
*val = 0;
return 0;
}
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;
}
