diff options
| -rw-r--r-- | include/linux/mmu_notifier.h | 5 | ||||
| -rw-r--r-- | mm/oom_kill.c | 16 |
2 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index a1a210d59961..25c0dc31f084 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -419,6 +419,11 @@ extern void mmu_notifier_synchronize(void); #else /* CONFIG_MMU_NOTIFIER */ +static inline int mm_has_notifiers(struct mm_struct *mm) +{ + return 0; +} + static inline void mmu_notifier_release(struct mm_struct *mm) { } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index ec9f11d4f094..d631d251c150 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -37,6 +37,7 @@ #include <linux/ratelimit.h> #include <linux/kthread.h> #include <linux/init.h> +#include <linux/mmu_notifier.h> #include <asm/tlb.h> #include "internal.h" @@ -491,6 +492,21 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) } /* + * If the mm has notifiers then we would need to invalidate them around + * unmap_page_range and that is risky because notifiers can sleep and + * what they do is basically undeterministic. So let's have a short + * sleep to give the oom victim some more time. + * TODO: we really want to get rid of this ugly hack and make sure that + * notifiers cannot block for unbounded amount of time and add + * mmu_notifier_invalidate_range_{start,end} around unmap_page_range + */ + if (mm_has_notifiers(mm)) { + up_read(&mm->mmap_sem); + schedule_timeout_idle(HZ); + goto unlock_oom; + } + + /* * increase mm_users only after we know we will reap something so * that the mmput_async is called only when we have reaped something * and delayed __mmput doesn't matter that much |