From f340ff820345b179b697f66ec6743c70416bf93f Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 31 Jan 2018 16:18:36 -0800 Subject: [PATCH] mm, oom: avoid reaping only for mm's with blockable invalidate callbacks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- mm/oom_kill.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 29f855551efe..f2e7dfb81eee 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",