Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Jianfeng Wang <> | Subject | [PATCH] mm, oom: Add lru_add_drain() in __oom_reap_task_mm() | Date | Tue, 9 Jan 2024 01:15:11 -0800 |
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The oom_reaper tries to reclaim additional memory owned by the oom victim. In __oom_reap_task_mm(), it uses mmu_gather for batched page free. After oom_reaper was added, mmu_gather feature introduced CONFIG_MMU_GATHER_NO_GATHER (in 'commit 952a31c9e6fa ("asm-generic/tlb: Introduce CONFIG_HAVE_MMU_GATHER_NO_GATHER=y")', an option to skip batched page free. If set, tlb_batch_pages_flush(), which is responsible for calling lru_add_drain(), is skipped during tlb_finish_mmu(). Without it, pages could still be held by per-cpu fbatches rather than be freed.
This fix adds lru_add_drain() prior to mmu_gather. This makes the code consistent with other cases where mmu_gather is used for freeing pages.
Signed-off-by: Jianfeng Wang <jianfeng.w.wang@oracle.com> --- mm/oom_kill.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 9e6071fde34a..e2fcf4f062ea 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -537,6 +537,7 @@ static bool __oom_reap_task_mm(struct mm_struct *mm) struct mmu_notifier_range range; struct mmu_gather tlb; + lru_add_drain(); mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, mm, vma->vm_start, vma->vm_end); -- 2.42.1
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