Messages in this thread | | | Date | Sat, 1 Oct 2022 07:09:50 +0800 | Subject | Re: [PATCH v3 1/2] mm: use update_mmu_tlb() on the second thread | From | Qi Zheng <> |
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On 2022/10/1 06:31, Andrew Morton wrote: > 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; > } > > _
Thank you very much! :)
>
-- Thanks, Qi
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