Subject: + xtensa-use-buddy-allocator-for-pte-table.patch added to -mm tree To: kirill.shutemov@xxxxxxxxxxxxxxx,chris@xxxxxxxxxx,jcmvbkbc@xxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 14 Oct 2013 15:50:02 -0700 The patch titled Subject: Re: xtensa: use buddy allocator for PTE table has been added to the -mm tree. Its filename is xtensa-use-buddy-allocator-for-pte-table.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/xtensa-use-buddy-allocator-for-pte-table.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/xtensa-use-buddy-allocator-for-pte-table.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Subject: Re: xtensa: use buddy allocator for PTE table At the moment xtensa uses slab allocator for PTE table. It doesn't work with enabled split page table lock: slab uses page->slab_cache and page->first_page for its pages. These fields share stroage with page->ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Chris Zankel <chris@xxxxxxxxxx> Cc: Max Filippov <jcmvbkbc@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/xtensa/include/asm/pgalloc.h | 20 ++++++++++++-------- arch/xtensa/include/asm/pgtable.h | 3 +-- arch/xtensa/mm/mmu.c | 20 -------------------- 3 files changed, 13 insertions(+), 30 deletions(-) diff -puN arch/xtensa/include/asm/pgalloc.h~xtensa-use-buddy-allocator-for-pte-table arch/xtensa/include/asm/pgalloc.h --- a/arch/xtensa/include/asm/pgalloc.h~xtensa-use-buddy-allocator-for-pte-table +++ a/arch/xtensa/include/asm/pgalloc.h @@ -38,14 +38,18 @@ static inline void pgd_free(struct mm_st free_page((unsigned long)pgd); } -/* Use a slab cache for the pte pages (see also sparc64 implementation) */ - -extern struct kmem_cache *pgtable_cache; - static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) { - return kmem_cache_alloc(pgtable_cache, GFP_KERNEL|__GFP_REPEAT); + pte_t *ptep; + int i; + + ptep = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); + if (!ptep) + return NULL; + for (i = 0; i < 1024; i++) + pte_clear(NULL, 0, ptep + i); + return ptep; } static inline pgtable_t pte_alloc_one(struct mm_struct *mm, @@ -59,7 +63,7 @@ static inline pgtable_t pte_alloc_one(st return NULL; page = virt_to_page(pte); if (!pgtable_page_ctor(page)) { - kmem_cache_free(pgtable_cache, pte); + __free_page(page); return NULL; } return page; @@ -67,13 +71,13 @@ static inline pgtable_t pte_alloc_one(st static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) { - kmem_cache_free(pgtable_cache, pte); + free_page((unsigned long)pte); } static inline void pte_free(struct mm_struct *mm, pgtable_t pte) { pgtable_page_dtor(pte); - kmem_cache_free(pgtable_cache, page_address(pte)); + __free_page(pte); } #define pmd_pgtable(pmd) pmd_page(pmd) diff -puN arch/xtensa/include/asm/pgtable.h~xtensa-use-buddy-allocator-for-pte-table arch/xtensa/include/asm/pgtable.h --- a/arch/xtensa/include/asm/pgtable.h~xtensa-use-buddy-allocator-for-pte-table +++ a/arch/xtensa/include/asm/pgtable.h @@ -220,12 +220,11 @@ extern unsigned long empty_zero_page[102 #ifdef CONFIG_MMU extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)]; extern void paging_init(void); -extern void pgtable_cache_init(void); #else # define swapper_pg_dir NULL static inline void paging_init(void) { } -static inline void pgtable_cache_init(void) { } #endif +static inline void pgtable_cache_init(void) { } /* * The pmd contains the kernel virtual address of the pte page. diff -puN arch/xtensa/mm/mmu.c~xtensa-use-buddy-allocator-for-pte-table arch/xtensa/mm/mmu.c --- a/arch/xtensa/mm/mmu.c~xtensa-use-buddy-allocator-for-pte-table +++ a/arch/xtensa/mm/mmu.c @@ -50,23 +50,3 @@ void __init init_mmu(void) */ set_ptevaddr_register(PGTABLE_START); } - -struct kmem_cache *pgtable_cache __read_mostly; - -static void pgd_ctor(void *addr) -{ - pte_t *ptep = (pte_t *)addr; - int i; - - for (i = 0; i < 1024; i++, ptep++) - pte_clear(NULL, 0, ptep); - -} - -void __init pgtable_cache_init(void) -{ - pgtable_cache = kmem_cache_create("pgd", - PAGE_SIZE, PAGE_SIZE, - SLAB_HWCACHE_ALIGN, - pgd_ctor); -} _ Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are mm-huge_memoryc-fix-stale-comments-of-transparent_hugepage_flags.patch mm-thp-cleanup-mv-alloc_hugepage-to-better-place.patch mm-thp-khugepaged-add-policy-for-finding-target-node.patch mm-thp-khugepaged-add-policy-for-finding-target-node-fix.patch mm-avoid-increase-sizeofstruct-page-due-to-split-page-table-lock.patch mm-rename-use_split_ptlocks-to-use_split_pte_ptlocks.patch mm-convert-mm-nr_ptes-to-atomic_long_t.patch mm-introduce-api-for-split-page-table-lock-for-pmd-level.patch mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch mm-thp-move-ptl-taking-inside-page_check_address_pmd.patch mm-thp-do-not-access-mm-pmd_huge_pte-directly.patch mm-hugetlb-convert-hugetlbfs-to-use-split-pmd-lock.patch mm-hugetlb-convert-hugetlbfs-to-use-split-pmd-lock-checkpatch-fixes.patch mm-convert-the-rest-to-new-page-table-lock-api.patch mm-implement-split-page-table-lock-for-pmd-level.patch x86-mm-enable-split-page-table-lock-for-pmd-level.patch x86-mm-enable-split-page-table-lock-for-pmd-level-checkpatch-fixes.patch x86-add-missed-pgtable_pmd_page_ctor-dtor-calls-for-preallocated-pmds.patch cris-fix-potential-null-pointer-dereference.patch m32r-fix-potential-null-pointer-dereference.patch xtensa-fix-potential-null-pointer-dereference.patch mm-allow-pgtable_page_ctor-to-fail.patch microblaze-add-missing-pgtable_page_ctor-dtor-calls.patch mn10300-add-missing-pgtable_page_ctor-dtor-calls.patch openrisc-add-missing-pgtable_page_ctor-dtor-calls.patch alpha-handle-pgtable_page_ctor-fail.patch arc-handle-pgtable_page_ctor-fail.patch arm-handle-pgtable_page_ctor-fail.patch arm64-handle-pgtable_page_ctor-fail.patch avr32-handle-pgtable_page_ctor-fail.patch cris-handle-pgtable_page_ctor-fail.patch frv-handle-pgtable_page_ctor-fail.patch hexagon-handle-pgtable_page_ctor-fail.patch ia64-handle-pgtable_page_ctor-fail.patch m32r-handle-pgtable_page_ctor-fail.patch m68k-handle-pgtable_page_ctor-fail.patch metag-handle-pgtable_page_ctor-fail.patch mips-handle-pgtable_page_ctor-fail.patch parisc-handle-pgtable_page_ctor-fail.patch powerpc-handle-pgtable_page_ctor-fail.patch s390-handle-pgtable_page_ctor-fail.patch score-handle-pgtable_page_ctor-fail.patch sh-handle-pgtable_page_ctor-fail.patch sparc-handle-pgtable_page_ctor-fail.patch tile-handle-pgtable_page_ctor-fail.patch um-handle-pgtable_page_ctor-fail.patch unicore32-handle-pgtable_page_ctor-fail.patch x86-handle-pgtable_page_ctor-fail.patch xtensa-handle-pgtable_page_ctor-fail.patch iommu-arm-smmu-handle-pgtable_page_ctor-fail.patch xtensa-use-buddy-allocator-for-pte-table.patch mm-dynamically-allocate-page-ptl-if-it-cannot-be-embedded-to-struct-page.patch mm-dynamically-allocate-page-ptl-if-it-cannot-be-embedded-to-struct-page-fix.patch mm-dynamically-allocate-page-ptl-if-it-cannot-be-embedded-to-struct-page-fix-fix.patch thp-mm-locking-tail-page-is-a-bug.patch mm-drop-actor-argument-of-do_generic_file_read.patch mm-drop-actor-argument-of-do_generic_file_read-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html