[PATCH] arm64: mm: enable per pmd page table lock
From: Yu Zhao <hidden>
Date: 2019-02-14 21:16:57
Also in:
linux-arch, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), mmu gather and tlb invalidation, the rest · Maintainers:
Catalin Marinas, Will Deacon, "Aneesh Kumar K.V", Andrew Morton, Nick Piggin, Peter Zijlstra, Linus Torvalds
Switch from per mm_struct to per pmd page table lock by enabling ARCH_ENABLE_SPLIT_PMD_PTLOCK. This provides better granularity for large system. I'm not sure if there is contention on mm->page_table_lock. Given the option comes at no cost (apart from initializing more spin locks), why not enable it now. Signed-off-by: Yu Zhao <redacted> --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/pgalloc.h | 12 +++++++++++- arch/arm64/include/asm/tlb.h | 5 ++++- 3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a4168d366127..104325a1ffc3 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -872,6 +872,9 @@ config ARCH_WANT_HUGE_PMD_SHARE config ARCH_HAS_CACHE_LINE_SIZE def_bool y +config ARCH_ENABLE_SPLIT_PMD_PTLOCK + def_bool y + config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" ---help---
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 52fa47c73bf0..dabba4b2c61f 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h@@ -33,12 +33,22 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr) { - return (pmd_t *)__get_free_page(PGALLOC_GFP); + struct page *page; + + page = alloc_page(PGALLOC_GFP); + if (!page) + return NULL; + if (!pgtable_pmd_page_ctor(page)) { + __free_page(page); + return NULL; + } + return page_address(page); } static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp) { BUG_ON((unsigned long)pmdp & (PAGE_SIZE-1)); + pgtable_pmd_page_dtor(virt_to_page(pmdp)); free_page((unsigned long)pmdp); }
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 106fdc951b6e..4e3becfed387 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h@@ -62,7 +62,10 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) { - tlb_remove_table(tlb, virt_to_page(pmdp)); + struct page *page = virt_to_page(pmdp); + + pgtable_pmd_page_dtor(page); + tlb_remove_table(tlb, page); } #endif
--
2.21.0.rc0.258.g878e2cd30e-goog
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