From: Baolin Wang Date: Mon, 18 Sep 2023 06:31:42 +0000 (+0800) Subject: mm: add statistics for PUD level pagetable X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=55d2a0bd5eadaade850efa9d3a7ffbb0aeb67198;p=linux.git mm: add statistics for PUD level pagetable Recently, we found that cross-die access to pagetable pages on ARM64 machines can cause performance fluctuations in our business. Currently, there are no PMU events available to track this situation on our ARM64 machines, so accurate pagetable accounting can help to analyze this issue, but now the PUD level pagetable accounting is missed. So introduce pagetable_pud_ctor/dtor() to help to get accurate PUD pagetable accounting, as well as converting the architectures which use generic PUD pagetable allocation to add corresponding PUD pagetable accounting. Moreover this patch will mark the PUD level pagetable with PG_table flag, which will help to do sanity validation in unpoison_memory(). On my testing machine, I can see more pagetables statistics after the patch with page-types tool: Before patch: flags page-count MB symbolic-flags long-symbolic-flags 0x0000000004000000 27326 106 __________________________g_________________ pgtable After patch: 0x0000000004000000 27541 107 __________________________g_________________ pgtable Link: https://lkml.kernel.org/r/876c71c03a7e69c17722a690e3225a4f7b172fb2.1695017383.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang Acked-by: Mike Rapoport (IBM) Acked-by: Vishal Moola (Oracle) Cc: Andy Lutomirski Cc: Aneesh Kumar K.V Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Catalin Marinas Cc: Dave Hansen Cc: Huacai Chen Cc: Ingo Molnar Cc: Matthew Wilcox (Oracle) Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton --- diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h index 2c29239d05c3e..846c563689a81 100644 --- a/arch/arm64/include/asm/tlb.h +++ b/arch/arm64/include/asm/tlb.h @@ -96,7 +96,10 @@ 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_ptdesc(tlb, virt_to_ptdesc(pudp)); + struct ptdesc *ptdesc = virt_to_ptdesc(pudp); + + pagetable_pud_dtor(ptdesc); + tlb_remove_ptdesc(tlb, ptdesc); } #endif diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h index 79470f0b4f1d8..4e2d6b7ca2eeb 100644 --- a/arch/loongarch/include/asm/pgalloc.h +++ b/arch/loongarch/include/asm/pgalloc.h @@ -84,6 +84,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address) if (!ptdesc) return NULL; + pagetable_pud_ctor(ptdesc); pud = ptdesc_address(ptdesc); pud_init(pud); diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h index 40e40a7eb94af..f4440edcd8fe2 100644 --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -95,6 +95,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address) if (!ptdesc) return NULL; + pagetable_pud_ctor(ptdesc); pud = ptdesc_address(ptdesc); pud_init(pud); diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 9deadf517f14a..0cbc1b8e8e3d1 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -76,6 +76,9 @@ 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 ptdesc *ptdesc = virt_to_ptdesc(pud); + + pagetable_pud_dtor(ptdesc); paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); paravirt_tlb_remove_table(tlb, virt_to_page(pud)); } diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index c75d4a7538493..879e5f8aa5e92 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -169,6 +169,8 @@ static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr) ptdesc = pagetable_alloc(gfp, 0); if (!ptdesc) return NULL; + + pagetable_pud_ctor(ptdesc); return ptdesc_address(ptdesc); } @@ -190,8 +192,11 @@ 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 ptdesc *ptdesc = virt_to_ptdesc(pud); + BUG_ON((unsigned long)pud & (PAGE_SIZE-1)); - pagetable_free(virt_to_ptdesc(pud)); + pagetable_pud_dtor(ptdesc); + pagetable_free(ptdesc); } #ifndef __HAVE_ARCH_PUD_FREE diff --git a/include/linux/mm.h b/include/linux/mm.h index 31dc25d3f6b5a..126b54b454423 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3049,6 +3049,22 @@ static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud) return ptl; } +static inline void pagetable_pud_ctor(struct ptdesc *ptdesc) +{ + struct folio *folio = ptdesc_folio(ptdesc); + + __folio_set_pgtable(folio); + lruvec_stat_add_folio(folio, NR_PAGETABLE); +} + +static inline void pagetable_pud_dtor(struct ptdesc *ptdesc) +{ + struct folio *folio = ptdesc_folio(ptdesc); + + __folio_clear_pgtable(folio); + lruvec_stat_sub_folio(folio, NR_PAGETABLE); +} + extern void __init pagecache_init(void); extern void free_initmem(void);