Messages in this thread | | | Date | Thu, 29 Sep 2022 11:47:13 +0800 | Subject | Re: [PATCH v2] mm: use update_mmu_tlb() on the second thread | From | Qi Zheng <> |
| |
On 2022/9/29 11:27, maobibo wrote: > 在 2022/9/29 11:07, Qi Zheng 写道: >> >> >> On 2022/9/26 22:34, David Hildenbrand wrote: >>> On 26.09.22 13:56, 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. >>>> >>>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> >>>> Reviewed-by: Muchun Song <songmuchun@bytedance.com> >>>> --- >>>> v1: https://lore.kernel.org/lkml/20220924053239.91661-1-zhengqi.arch@bytedance.com/ >>>> >>>> Changelog in v1 -> v2: >>>> - change the subject and commit message (David) >>>> >>>> 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; >>>> } >>> >>> >>> Staring at 7df676974359, it indeed looks like an accidental use [nothing else in that patch uses update_mmu_cache]. >>> >>> So it looks good to me, but a confirmation from Bibo Mao might be good. >> >> Thanks, and Hi Bibo, any comments here? :) > > update_mmu_tlb is defined as empty on loongarch, maybe some lines should > be added in file arch/loongarch/include/asm/pgtable.h like this:
Seems like a bug? Because there are many other places where update_mmu_tlb() is called.
> > +#define __HAVE_ARCH_UPDATE_MMU_TLB > +#define update_mmu_tlb update_mmu_cache
If so, I can make the above as a separate fix patch.
Thanks, Qi
> > regards > bibo mao >> >>> >> >
-- Thanks, Qi
| |