From: David Rientjes Date: Thu, 1 Feb 2018 00:18:36 +0000 (-0800) Subject: mm, oom: avoid reaping only for mm's with blockable invalidate callbacks X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f340ff820345b179b697f66ec6743c70416bf93f;p=linux.git mm, oom: avoid reaping only for mm's with blockable invalidate callbacks This uses the new annotation to determine if an mm has mmu notifiers with blockable invalidate range callbacks to avoid oom reaping. Otherwise, the callbacks are used around unmap_page_range(). Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141330120.74052@chino.kir.corp.google.com Signed-off-by: David Rientjes Acked-by: Michal Hocko Cc: Paolo Bonzini Cc: Christian König Cc: Dimitri Sivanich Cc: Andrea Arcangeli Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Oded Gabbay Cc: Alex Deucher Cc: David Airlie Cc: Joerg Roedel Cc: Doug Ledford Cc: Jani Nikula Cc: Mike Marciniszyn Cc: Sean Hefty Cc: Boris Ostrovsky Cc: Jérôme Glisse Cc: Radim Krčmář Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 29f855551efef..f2e7dfb81eeee 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -514,15 +514,12 @@ 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 + * If the mm has invalidate_{start,end}() notifiers that could block, * 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 + * notifiers cannot block for unbounded amount of time */ - if (mm_has_notifiers(mm)) { + if (mm_has_blockable_invalidate_notifiers(mm)) { up_read(&mm->mmap_sem); schedule_timeout_idle(HZ); goto unlock_oom; @@ -565,10 +562,14 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) * count elevated without a good reason. */ if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) { - tlb_gather_mmu(&tlb, mm, vma->vm_start, vma->vm_end); - unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end, - NULL); - tlb_finish_mmu(&tlb, vma->vm_start, vma->vm_end); + const unsigned long start = vma->vm_start; + const unsigned long end = vma->vm_end; + + tlb_gather_mmu(&tlb, mm, start, end); + mmu_notifier_invalidate_range_start(mm, start, end); + unmap_page_range(&tlb, vma, start, end, NULL); + mmu_notifier_invalidate_range_end(mm, start, end); + tlb_finish_mmu(&tlb, start, end); } } pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",