Messages in this thread |  | | Date | Fri, 1 Jul 2022 16:04:21 +0800 | Subject | Re: [RFC PATCH v3 2/3] mm: Add PUD level pagetable account | From | Baolin Wang <> |
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On 6/30/2022 10:17 PM, Mike Rapoport wrote: > On Thu, Jun 30, 2022 at 07:11:15PM +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_page_inc() or >> pgtable_page_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_page_inc() or pgtable_page_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..1772df9 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_page_dec(page); > > Using pgtable_pud_page_ctor() and pgtable_pud_page_dtor() would be > consistent with what we currently have for PTEs and PMDs. > > This applies to all the additions of pgtable_page_dec() and > pgtable_page_inc().
OK. I can add pgtable_pud_page_ctor() and pgtable_pud_page_dtor() helpers to keep consistent, which are just wrappers of pgtable_page_inc() and pgtable_page_dec().
> >> + tlb_remove_table(tlb, page); >> } >> #endif >> >> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h >> index b0a57b2..19bfe14 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 *page; >> >> - pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_ORDER); >> - if (pud) >> - pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table); >> + page = alloc_pages(GFP_KERNEL, PUD_ORDER); >> + if (!page) >> + return NULL; >> + >> + pgtable_page_inc(page); >> + pud = (pud_t *)page_address(page); >> + pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table); >> return pud; >> } >> >> diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h >> index 867e9c3..990f614 100644 >> --- a/arch/mips/include/asm/pgalloc.h >> +++ b/arch/mips/include/asm/pgalloc.h >> @@ -89,11 +89,16 @@ 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) >> { >> + struct page *page; >> pud_t *pud; >> >> - pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_ORDER); >> - if (pud) >> - pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table); >> + page = alloc_pages(GFP_KERNEL, PUD_ORDER); >> + if (!page) >> + return NULL; >> + >> + pgtable_page_inc(page); >> + pud = (pud_t *)page_address(page); >> + pud_init((unsigned long)pud, (unsigned long)invalid_pmd_table); >> return pud; >> } >> >> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h >> index fe6407f..744e2d7 100644 >> --- a/arch/s390/include/asm/tlb.h >> +++ b/arch/s390/include/asm/tlb.h >> @@ -125,6 +125,7 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, >> { >> if (mm_pud_folded(tlb->mm)) >> return; >> + pgtable_page_dec(virt_to_page(pud)); >> tlb->mm->context.flush_mm = 1; >> tlb->freed_tables = 1; >> tlb->cleared_p4ds = 1; >> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c >> index a932d77..5e46e31 100644 >> --- a/arch/x86/mm/pgtable.c >> +++ b/arch/x86/mm/pgtable.c >> @@ -76,8 +76,11 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) >> #if CONFIG_PGTABLE_LEVELS > 3 >> void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) >> { >> + struct page *page = virt_to_page(pud); >> + >> + pgtable_page_dec(page); >> paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); >> - paravirt_tlb_remove_table(tlb, virt_to_page(pud)); >> + paravirt_tlb_remove_table(tlb, page); >> } >> >> #if CONFIG_PGTABLE_LEVELS > 4 >> diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h >> index 977bea1..11350f7 100644 >> --- a/include/asm-generic/pgalloc.h >> +++ b/include/asm-generic/pgalloc.h >> @@ -149,11 +149,16 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) >> >> static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr) >> { >> + struct page *page; >> gfp_t gfp = GFP_PGTABLE_USER; >> >> if (mm == &init_mm) >> gfp = GFP_PGTABLE_KERNEL; >> - return (pud_t *)get_zeroed_page(gfp); >> + page = alloc_pages(gfp, 0); >> + if (!page) >> + return NULL; >> + pgtable_page_inc(page); >> + return (pud_t *)page_address(page); >> } >> >> #ifndef __HAVE_ARCH_PUD_ALLOC_ONE >> @@ -174,8 +179,11 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) >> >> static inline void __pud_free(struct mm_struct *mm, pud_t *pud) >> { >> + struct page *page = virt_to_page(pud); >> + >> BUG_ON((unsigned long)pud & (PAGE_SIZE-1)); >> - free_page((unsigned long)pud); >> + pgtable_page_dec(page); >> + __free_page(page); >> } >> >> #ifndef __HAVE_ARCH_PUD_FREE >> -- >> 1.8.3.1 >> >
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