Messages in this thread | | | Date | Thu, 23 Jun 2022 11:32:37 +0800 | Subject | Re: [RFC PATCH v2 2/3] mm: Add PUD level pagetable account | From | Baolin Wang <> |
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On 6/22/2022 10:38 PM, Mike Rapoport wrote: > On Wed, Jun 22, 2022 at 04:58:53PM +0800, Baolin Wang wrote: >> Now the PUD level ptes are always protected by mm->page_table_lock, >> which means no split pagetable lock needed. So the generic PUD level >> pagetable pages allocation will not call pgtable_pte_page_ctor/dtor(), >> that means we will miss to account PUD level pagetable pages. >> >> Adding pagetable account by calling pgtable_set_and_inc() or >> pgtable_clear_and_dec() when allocating or freeing PUD level pagetable >> pages to help to get an accurate pagetable accounting. >> >> Moreover this patch will also mark the PUD level pagetable with PG_table >> flag, which will help to do sanity validation in unpoison_memory() and >> get more accurate pagetable accounting by /proc/kpageflags interface. >> >> Meanwhile converting the architectures with using generic PUD pagatable >> allocation to add corresponding pgtable_set_and_inc() or pgtable_clear_and_dec() >> to account PUD level pagetable. >> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> arch/arm64/include/asm/tlb.h | 5 ++++- >> arch/loongarch/include/asm/pgalloc.h | 11 ++++++++--- >> arch/mips/include/asm/pgalloc.h | 11 ++++++++--- >> arch/s390/include/asm/tlb.h | 1 + >> arch/x86/mm/pgtable.c | 5 ++++- >> include/asm-generic/pgalloc.h | 12 ++++++++++-- >> 6 files changed, 35 insertions(+), 10 deletions(-) >> >> diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h >> index c995d1f..47e0623 100644 >> --- a/arch/arm64/include/asm/tlb.h >> +++ b/arch/arm64/include/asm/tlb.h >> @@ -94,7 +94,10 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, >> static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp, >> unsigned long addr) >> { >> - tlb_remove_table(tlb, virt_to_page(pudp)); >> + struct page *page = virt_to_page(pudp); >> + >> + pgtable_clear_and_dec(page); >> + tlb_remove_table(tlb, page); >> } >> #endif >> >> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h >> index b0a57b2..50a896f 100644 >> --- a/arch/loongarch/include/asm/pgalloc.h >> +++ b/arch/loongarch/include/asm/pgalloc.h >> @@ -89,10 +89,15 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) >> static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address) >> { >> pud_t *pud; >> + struct page *pg; > > struct page *page; > > looks better IMO.
Sure.
> >> + >> + pg = alloc_pages(GFP_KERNEL & ~__GFP_HIGHMEM, PUD_ORDER); >> + if (!pg) >> + return NULL; >> >> - pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_ORDER); >> - if (pud) >> - pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table); >> + pgtable_set_and_inc(pg); >> + pud = (pud_t *)page_address(pg); > > I don't think __get_free_pages() should be replaced with alloc_pages() > here, just call pgtable_set_and_inc() with virt_to_page(pud). > > The same applies for the cases below.
Sure. Will do in next version. Thanks.
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