mm, oom: avoid reaping only for mm's with blockable invalidate callbacks (f340ff82) · Commits · 戴 / test

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 <rientjes@google.com> Acked-by:

Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Christian König <christian.koenig@amd.com> Cc: Dimitri Sivanich <sivanich@hpe.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Oded Gabbay <oded.gabbay@gmail.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Joerg Roedel <joro@8bytes.org> Cc: Doug Ledford <dledford@redhat.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/oom_kill.c

+11 −10

Original line number	Diff line number	Diff line
		@@ -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",

Admin message