Revert "oom_kill.c: futex: delay the OOM reaper to allow time for proper futex cleanup"

This reverts commit 0441d3e95b.  It breaks
the abi and is not needed for Android devices.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I0d9f161b4250bb6ec960e2a5ee2f425f6f8dbf4e
This commit is contained in:
Greg Kroah-Hartman 2022-04-27 15:23:14 +02:00
parent 36dda9143f
commit 84c84ac7a3
2 changed files with 15 additions and 42 deletions

View File

@ -1271,7 +1271,6 @@ struct task_struct {
int pagefault_disabled;
#ifdef CONFIG_MMU
struct task_struct *oom_reaper_list;
struct timer_list oom_reaper_timer;
#endif
#ifdef CONFIG_VMAP_STACK
struct vm_struct *stack_vm_area;

View File

@ -631,7 +631,7 @@ done:
*/
set_bit(MMF_OOM_SKIP, &mm->flags);
/* Drop a reference taken by queue_oom_reaper */
/* Drop a reference taken by wake_oom_reaper */
put_task_struct(tsk);
}
@ -641,12 +641,12 @@ static int oom_reaper(void *unused)
struct task_struct *tsk = NULL;
wait_event_freezable(oom_reaper_wait, oom_reaper_list != NULL);
spin_lock_irq(&oom_reaper_lock);
spin_lock(&oom_reaper_lock);
if (oom_reaper_list != NULL) {
tsk = oom_reaper_list;
oom_reaper_list = tsk->oom_reaper_list;
}
spin_unlock_irq(&oom_reaper_lock);
spin_unlock(&oom_reaper_lock);
if (tsk)
oom_reap_task(tsk);
@ -655,46 +655,20 @@ static int oom_reaper(void *unused)
return 0;
}
static void wake_oom_reaper(struct timer_list *timer)
{
struct task_struct *tsk = container_of(timer, struct task_struct,
oom_reaper_timer);
struct mm_struct *mm = tsk->signal->oom_mm;
unsigned long flags;
/* The victim managed to terminate on its own - see exit_mmap */
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
put_task_struct(tsk);
return;
}
spin_lock_irqsave(&oom_reaper_lock, flags);
tsk->oom_reaper_list = oom_reaper_list;
oom_reaper_list = tsk;
spin_unlock_irqrestore(&oom_reaper_lock, flags);
trace_wake_reaper(tsk->pid);
wake_up(&oom_reaper_wait);
}
/*
* Give the OOM victim time to exit naturally before invoking the oom_reaping.
* The timers timeout is arbitrary... the longer it is, the longer the worst
* case scenario for the OOM can take. If it is too small, the oom_reaper can
* get in the way and release resources needed by the process exit path.
* e.g. The futex robust list can sit in Anon|Private memory that gets reaped
* before the exit path is able to wake the futex waiters.
*/
#define OOM_REAPER_DELAY (2*HZ)
static void queue_oom_reaper(struct task_struct *tsk)
static void wake_oom_reaper(struct task_struct *tsk)
{
/* mm is already queued? */
if (test_and_set_bit(MMF_OOM_REAP_QUEUED, &tsk->signal->oom_mm->flags))
return;
get_task_struct(tsk);
timer_setup(&tsk->oom_reaper_timer, wake_oom_reaper, 0);
tsk->oom_reaper_timer.expires = jiffies + OOM_REAPER_DELAY;
add_timer(&tsk->oom_reaper_timer);
spin_lock(&oom_reaper_lock);
tsk->oom_reaper_list = oom_reaper_list;
oom_reaper_list = tsk;
spin_unlock(&oom_reaper_lock);
trace_wake_reaper(tsk->pid);
wake_up(&oom_reaper_wait);
}
static int __init oom_init(void)
@ -704,7 +678,7 @@ static int __init oom_init(void)
}
subsys_initcall(oom_init)
#else
static inline void queue_oom_reaper(struct task_struct *tsk)
static inline void wake_oom_reaper(struct task_struct *tsk)
{
}
#endif /* CONFIG_MMU */
@ -953,7 +927,7 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
rcu_read_unlock();
if (can_oom_reap)
queue_oom_reaper(victim);
wake_oom_reaper(victim);
mmdrop(mm);
put_task_struct(victim);
@ -989,7 +963,7 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
task_lock(victim);
if (task_will_free_mem(victim)) {
mark_oom_victim(victim);
queue_oom_reaper(victim);
wake_oom_reaper(victim);
task_unlock(victim);
put_task_struct(victim);
return;
@ -1087,7 +1061,7 @@ bool out_of_memory(struct oom_control *oc)
*/
if (task_will_free_mem(current)) {
mark_oom_victim(current);
queue_oom_reaper(current);
wake_oom_reaper(current);
return true;
}