Messages in this thread | | | Date | Mon, 31 Jul 2023 19:20:03 +0800 | Subject | Re: [PATCH 2/4] mm: mremap: use flush_pmd_tlb_range() in move_normal_pmd() | From | Kefeng Wang <> |
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On 2023/7/31 19:05, Catalin Marinas wrote: > On Mon, Jul 31, 2023 at 03:48:27PM +0800, Kefeng Wang wrote: >> Archs may need to do special things when flushing thp tlb, >> so use the more applicable flush_pud_tlb_range() instead of >> flush_tlb_range(). >> >> Fixes: 2c91bd4a4e2e ("mm: speed up mremap by 20x on large regions") >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> mm/mremap.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/mremap.c b/mm/mremap.c >> index 11e06e4ab33b..1883205fa22b 100644 >> --- a/mm/mremap.c >> +++ b/mm/mremap.c >> @@ -284,7 +284,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, >> VM_BUG_ON(!pmd_none(*new_pmd)); >> >> pmd_populate(mm, new_pmd, pmd_pgtable(pmd)); >> - flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); >> + flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); > > I don't think that's correct for arm64. The assumption in the > flush_p*d_tlb_range() was that they are called only for block mappings > at that p*d level (and we use FEAT_TTL on arm64 indicating that the leaf > level is level 2 for pmd, 1 for pud). IIUC move_normal_pmd() is only > called for table pmds which would have a leaf level of 3 (the pte).
oops, yes, this is for NORMAL_PMD case, not HPAGE_PMD, please ignore patch 2/3.
> > Same for the next patch doing the equivalent for the pud. >
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