I got "oom_reaper: unable to reap pid:" messages when the victim thread
was blocked inside free_pgtables() (which occurred after returning from
unmap_vmas() and setting MMF_OOM_SKIP). We don't need to complain when
__oom_reap_task_mm() returned true (by e.g. finding MMF_OOM_SKIP already
set) when oom_reap_task() was trying MAX_OOM_REAP_RETRIES'th attempt.
[ 663.593821] Killed process 7558 (a.out) total-vm:4176kB, anon-rss:84kB, file-rss:0kB, shmem-rss:0kB
[ 664.684801] oom_reaper: unable to reap pid:7558 (a.out)
[ 664.892292] a.out D13272 7558 6931 0x00100084
[ 664.895765] Call Trace:
[ 664.897574] ? __schedule+0x25f/0x780
[ 664.900099] schedule+0x2d/0x80
[ 664.902260] rwsem_down_write_failed+0x2bb/0x440
[ 664.905249] ? rwsem_down_write_failed+0x55/0x440
[ 664.908335] ? free_pgd_range+0x569/0x5e0
[ 664.911145] call_rwsem_down_write_failed+0x13/0x20
[ 664.914121] down_write+0x49/0x60
[ 664.916519] ? unlink_file_vma+0x28/0x50
[ 664.919255] unlink_file_vma+0x28/0x50
[ 664.922234] free_pgtables+0x36/0x100
[ 664.924797] exit_mmap+0xbb/0x180
[ 664.927220] mmput+0x50/0x110
[ 664.929504] copy_process.part.41+0xb61/0x1fe0
[ 664.932448] ? _do_fork+0xe6/0x560
[ 664.934902] ? _do_fork+0xe6/0x560
[ 664.937361] _do_fork+0xe6/0x560
[ 664.939742] ? syscall_trace_enter+0x1a9/0x240
[ 664.942693] ? retint_user+0x18/0x18
[ 664.945309] ? page_fault+0x2f/0x50
[ 664.947896] ? trace_hardirqs_on_caller+0x11f/0x1b0
[ 664.951075] do_syscall_64+0x74/0x230
[ 664.953747] entry_SYSCALL_64_after_hwframe+0x42/0xb7
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
---
mm/oom_kill.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 900300c..1cb2b98 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -588,11 +588,11 @@ static void oom_reap_task(struct task_struct *tsk)
struct mm_struct *mm = tsk->signal->oom_mm;
/* Retry the down_read_trylock(mmap_sem) a few times */
- while (attempts++ < MAX_OOM_REAP_RETRIES && !__oom_reap_task_mm(tsk, mm))
+ while (attempts++ < MAX_OOM_REAP_RETRIES) {
+ if (__oom_reap_task_mm(tsk, mm))
+ goto done;
schedule_timeout_idle(HZ/10);
-
- if (attempts <= MAX_OOM_REAP_RETRIES)
- goto done;
+ }
pr_info("oom_reaper: unable to reap pid:%d (%s)\n",
--
1.8.3.1
