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 ret = 0;
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 = global_page_state(NR_FREE_PAGES);
int other_file = global_page_state(NR_FILE_PAGES) -
global_page_state(NR_SHMEM);
struct reclaim_state *reclaim_state = current->reclaim_state;
#ifdef CONFIG_ZSWAP
/* to prevent other_file underflow and then be negative */
if (other_file > total_swapcache_pages())
other_file -= total_swapcache_pages();
else
other_file = 0;
#endif
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 (sc->nr_to_scan > 0) {
ret = adjust_minadj(&min_score_adj);
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
sc->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 (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
if ((min_score_adj == OOM_SCORE_ADJ_MAX + 1) &&
(sc->nr_to_scan > 0))
trace_almk_shrink(0, ret, other_free, other_file, 0);
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)
continue;
p = find_lock_task_mm(tsk);
if (!p)
continue;
if (test_tsk_thread_flag(p, TIF_MEMDIE) &&
time_before_eq(jiffies, lowmem_deathpending_timeout)) {
task_unlock(p);
rcu_read_unlock();
/* give the system time to free up the memory */
msleep_interruptible(20);
return 0;
}
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 += (int)zswap_pool_pages * get_mm_counter(p->mm, MM_SWAPENTS)
/ atomic_read(&zswap_stored_pages);
lowmem_print(3, "real tasksize : %d\n", tasksize);
}
#endif
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(2, "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",
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));
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
rem -= selected_tasksize;
rcu_read_unlock();
lowmem_lmkcount++;
/* give the system time to free up the memory */
msleep_interruptible(20);
if(reclaim_state)
reclaim_state->reclaimed_slab += selected_tasksize;
trace_almk_shrink(selected_tasksize, ret,
other_free, other_file, selected_oom_score_adj);
} else {
trace_almk_shrink(1, ret, other_free, other_file, 0);
rcu_read_unlock();
}
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
return rem;
}
static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected[MANAGED_PROCESS_TYPES] = {NULL};
int rem = 0;
int ret = 0;
int tasksize;
int i;
short min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int minfree = 0;
enum lowmem_process_type proc_type = KILLABLE_PROCESS;
int selected_tasksize[MANAGED_PROCESS_TYPES] = {0};
int selected_oom_score_adj[MANAGED_PROCESS_TYPES];
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
int other_file = global_page_state(NR_FILE_PAGES) -
global_page_state(NR_SHMEM);
struct reclaim_state *reclaim_state = current->reclaim_state;
#ifdef CONFIG_ZSWAP
/* to prevent other_file underflow and then be negative */
if (other_file > total_swapcache_pages())
other_file -= total_swapcache_pages();
else
other_file = 0;
#endif
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 (sc->nr_to_scan > 0) {
ret = adjust_minadj(&min_score_adj);
lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
sc->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 (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
if ((min_score_adj == OOM_SCORE_ADJ_MAX + 1) &&
(sc->nr_to_scan > 0))
trace_almk_shrink(0, ret, other_free, other_file, 0);
return rem;
}
/* Set the initial oom_score_adj for each managed process type */
for (proc_type = KILLABLE_PROCESS; proc_type < MANAGED_PROCESS_TYPES; proc_type++)
selected_oom_score_adj[proc_type] = min_score_adj;
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
short oom_score_adj;
if (tsk->flags & PF_KTHREAD)
continue;
p = find_lock_task_mm(tsk);
if (!p)
continue;
if (test_tsk_thread_flag(p, TIF_MEMDIE) &&
time_before_eq(jiffies, lowmem_deathpending_timeout)) {
task_unlock(p);
rcu_read_unlock();
/* give the system time to free up the memory */
msleep_interruptible(20);
return 0;
}
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
task_unlock(p);
if (tasksize <= 0)
continue;
#ifdef CONFIG_ANDROID_LOW_MEMORY_KILLER_DO_NOT_KILL_PROCESS
/* Check if the process name is contained inside the process to be preserved lists */
if (is_in_donotkill_proc_list(p->comm)) {
/* This user process must be preserved from killing */
proc_type = DO_NOT_KILL_PROCESS;
lowmem_print(2, "The process '%s' is inside the donotkill_proc_names", p->comm);
} else if (is_in_donotkill_sysproc_list(p->comm)) {
/* This system process must be preserved from killing */
proc_type = DO_NOT_KILL_SYSTEM_PROCESS;
lowmem_print(2, "The process '%s' is inside the donotkill_sysproc_names", p->comm);
}
#endif
if (selected[proc_type]) {
if (oom_score_adj < selected_oom_score_adj[proc_type])
continue;
if (oom_score_adj == selected_oom_score_adj[proc_type] &&
tasksize <= selected_tasksize[proc_type])
continue;
}
selected[proc_type] = p;
selected_tasksize[proc_type] = tasksize;
selected_oom_score_adj[proc_type] = oom_score_adj;
lowmem_print(2, "select '%s' (%d), adj %hd, size %d, to kill\n",
p->comm, p->pid, oom_score_adj, tasksize);
}
/* For each managed process type check if a process to be killed has been found:
* - check first if a standard killable process has been found, if so kill it
* - if there is no killable process, then check if a user process has been found,
* if so kill it to prevent system slowdowns, hangs, etc.
* - if there is no killable and user process, then check if a system process has been found,
* if so kill it to prevent system slowdowns, hangs, etc. */
for (proc_type = KILLABLE_PROCESS; proc_type < MANAGED_PROCESS_TYPES; proc_type++) {
if (selected[proc_type]) {
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",
selected[proc_type]->comm, selected[proc_type]->pid,
selected_oom_score_adj[proc_type],
selected_tasksize[proc_type] * (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));
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected[proc_type], 0);
set_tsk_thread_flag(selected[proc_type], TIF_MEMDIE);
rem -= selected_tasksize[proc_type];
break;
} else {
trace_almk_shrink(1, ret, other_free, other_file, 0);
rcu_read_unlock();
}
}
trace_almk_shrink(1, ret, other_free, other_file, 0);
rcu_read_unlock();
lowmem_lmkcount++;
lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
return rem;
}