From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id 7DE696B0031 for ; Mon, 14 Oct 2013 11:19:10 -0400 (EDT) Received: by mail-pd0-f177.google.com with SMTP id y10so7416781pdj.8 for ; Mon, 14 Oct 2013 08:19:10 -0700 (PDT) Received: by mail-oa0-f51.google.com with SMTP id h16so4575193oag.24 for ; Mon, 14 Oct 2013 08:19:07 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1381761155-19166-2-git-send-email-kirill.shutemov@linux.intel.com> References: <1381761155-19166-1-git-send-email-kirill.shutemov@linux.intel.com> <1381761155-19166-2-git-send-email-kirill.shutemov@linux.intel.com> Date: Mon, 14 Oct 2013 19:19:07 +0400 Message-ID: Subject: Re: [PATCHv2 2/2] xtensa: use buddy allocator for PTE table From: Max Filippov Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Andrew Morton , Peter Zijlstra , Chris Zankel , Christoph Lameter , Pekka Enberg , Matt Mackall , LKML , "linux-mm@kvack.org" , Linux-Arch , "linux-xtensa@linux-xtensa.org" On Mon, Oct 14, 2013 at 6:32 PM, Kirill A. Shutemov wrote: > 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 > Cc: Chris Zankel > Cc: Max Filippov > --- > v2: > - add missed return in pte_alloc_one_kernel; > > 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 --git a/arch/xtensa/include/asm/pgalloc.h b/arch/xtensa/include/asm/pgalloc.h > index b8774f1e21..8507b32d6e 100644 > --- a/arch/xtensa/include/asm/pgalloc.h > +++ b/arch/xtensa/include/asm/pgalloc.h > @@ -38,14 +38,18 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) > 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++, ptep++) > + pte_clear(NULL, 0, ptep); > + return ptep; You're returning modified ptep, not the allocated one. > } > > static inline pgtable_t pte_alloc_one(struct mm_struct *mm, > @@ -59,7 +63,7 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm, > 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(struct mm_struct *mm, > > 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 --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h > index 0fdf5d043f..216446295a 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -220,12 +220,11 @@ extern unsigned long empty_zero_page[1024]; > #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 --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c > index a1077570e3..c43771c974 100644 > --- a/arch/xtensa/mm/mmu.c > +++ b/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); > -} > -- > 1.8.4.rc3 > -- Thanks. -- Max -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org