From 55d2a0bd5eadaade850efa9d3a7ffbb0aeb67198 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 18 Sep 2023 14:31:42 +0800 Subject: 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 --- arch/loongarch/include/asm/pgalloc.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/loongarch') diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h index 79470f0b4f1d..4e2d6b7ca2ee 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); -- cgit v1.2.3