Re: [PATCH v3 1/2] mm: use update_mmu_tlb() on the second thread

[Qi Zheng]

On 2022/9/30 16:30, David Hildenbrand wrote:
> On 29.09.22 13:23, Qi Zheng wrote:
> > 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.
>
> Maybe mention here "This only affects performance, but not correctness."

Oh, this is better. Hi Andrew, do I need to resend the v4?

> Acked-by: David Hildenbrand <david@xxxxxxxxxx>

Thanks.

> > Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> > Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > ---
> >   mm/memory.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/memory.c b/mm/memory.c
> > index 118e5f023597..9e11c783ba0e 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -4122,7 +4122,7 @@ static vm_fault_t do_anonymous_page(struct 
> > vm_fault *vmf)
> >       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;
> >       }

--
Thanks,
Qi