Messages in this thread Patch in this message | | | Date | Fri, 30 Sep 2022 15:31:35 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v3 1/2] mm: use update_mmu_tlb() on the second thread |
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On Fri, 30 Sep 2022 10:44:21 +0200 David Hildenbrand <david@redhat.com> wrote:
> > Oh, this is better. Hi Andrew, do I need to resend the v4? > > > > I assume he can squash it, most probably no need to resend. :)
From: Qi Zheng <zhengqi.arch@bytedance.com> Subject: mm: use update_mmu_tlb() on the second thread Date: Thu, 29 Sep 2022 19:23:17 +0800
As message in commit 7df676974359 ("mm/memory.c: Update local TLB if PTE entry exists") said, we should update local TLB only on the second thread. So in the do_anonymous_page() here, we should use update_mmu_tlb() instead of update_mmu_cache() on the second thread.
As David pointed out, this is a performance improvement, not a correctness fix.
Link: https://lkml.kernel.org/r/20220929112318.32393-2-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Huacai Chen <chenhuacai@loongson.cn> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> ---
mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memory.c~mm-use-update_mmu_tlb-on-the-second-thread +++ a/mm/memory.c @@ -4136,7 +4136,7 @@ static vm_fault_t do_anonymous_page(stru vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); if (!pte_none(*vmf->pte)) { - update_mmu_cache(vma, vmf->address, vmf->pte); + update_mmu_tlb(vma, vmf->address, vmf->pte); goto release; } _
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