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-rw-r--r--include/linux/sched.h3
-rw-r--r--mm/oom_kill.c36
2 files changed, 22 insertions, 17 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 478b41de7f7d..788f223f8f8f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1849,6 +1849,9 @@ struct task_struct {
unsigned long task_state_change;
#endif
int pagefault_disabled;
+#ifdef CONFIG_MMU
+ struct list_head oom_reaper_list;
+#endif
/* CPU-specific state of this task */
struct thread_struct thread;
/*
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 30a60991173a..f6d4ae9f1c69 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -418,8 +418,10 @@ bool oom_killer_disabled __read_mostly;
* victim (if that is possible) to help the OOM killer to move on.
*/
static struct task_struct *oom_reaper_th;
-static struct task_struct *task_to_reap;
static DECLARE_WAIT_QUEUE_HEAD(oom_reaper_wait);
+static LIST_HEAD(oom_reaper_list);
+static DEFINE_SPINLOCK(oom_reaper_lock);
+
static bool __oom_reap_task(struct task_struct *tsk)
{
@@ -524,12 +526,20 @@ static void oom_reap_task(struct task_struct *tsk)
static int oom_reaper(void *unused)
{
while (true) {
- struct task_struct *tsk;
+ struct task_struct *tsk = NULL;
wait_event_freezable(oom_reaper_wait,
- (tsk = READ_ONCE(task_to_reap)));
- oom_reap_task(tsk);
- WRITE_ONCE(task_to_reap, NULL);
+ (!list_empty(&oom_reaper_list)));
+ spin_lock(&oom_reaper_lock);
+ if (!list_empty(&oom_reaper_list)) {
+ tsk = list_first_entry(&oom_reaper_list,
+ struct task_struct, oom_reaper_list);
+ list_del(&tsk->oom_reaper_list);
+ }
+ spin_unlock(&oom_reaper_lock);
+
+ if (tsk)
+ oom_reap_task(tsk);
}
return 0;
@@ -537,23 +547,15 @@ static int oom_reaper(void *unused)
static void wake_oom_reaper(struct task_struct *tsk)
{
- struct task_struct *old_tsk;
-
if (!oom_reaper_th)
return;
get_task_struct(tsk);
- /*
- * Make sure that only a single mm is ever queued for the reaper
- * because multiple are not necessary and the operation might be
- * disruptive so better reduce it to the bare minimum.
- */
- old_tsk = cmpxchg(&task_to_reap, NULL, tsk);
- if (!old_tsk)
- wake_up(&oom_reaper_wait);
- else
- put_task_struct(tsk);
+ spin_lock(&oom_reaper_lock);
+ list_add(&tsk->oom_reaper_list, &oom_reaper_list);
+ spin_unlock(&oom_reaper_lock);
+ wake_up(&oom_reaper_wait);
}
static int __init oom_init(void)