From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965210AbbFCRTR (ORCPT ); Wed, 3 Jun 2015 13:19:17 -0400 Received: from mga11.intel.com ([192.55.52.93]:14278 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933157AbbFCRGb (ORCPT ); Wed, 3 Jun 2015 13:06:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,548,1427785200"; d="scan'208";a="740295247" From: "Kirill A. Shutemov" To: Andrew Morton , Andrea Arcangeli , Hugh Dickins Cc: Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv6 16/36] mm, thp: remove compound_lock Date: Wed, 3 Jun 2015 20:05:47 +0300 Message-Id: <1433351167-125878-17-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We are going to use migration entries to stabilize page counts. It means we don't need compound_lock() for that. Signed-off-by: Kirill A. Shutemov Tested-by: Sasha Levin Acked-by: Vlastimil Babka --- include/linux/mm.h | 35 ----------------------------------- include/linux/page-flags.h | 12 +----------- mm/debug.c | 3 --- mm/memcontrol.c | 11 +++-------- 4 files changed, 4 insertions(+), 57 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index f079d9ffc797..31cd5be081cf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -403,41 +403,6 @@ static inline int is_vmalloc_or_module_addr(const void *x) extern void kvfree(const void *addr); -static inline void compound_lock(struct page *page) -{ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - VM_BUG_ON_PAGE(PageSlab(page), page); - bit_spin_lock(PG_compound_lock, &page->flags); -#endif -} - -static inline void compound_unlock(struct page *page) -{ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - VM_BUG_ON_PAGE(PageSlab(page), page); - bit_spin_unlock(PG_compound_lock, &page->flags); -#endif -} - -static inline unsigned long compound_lock_irqsave(struct page *page) -{ - unsigned long uninitialized_var(flags); -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - local_irq_save(flags); - compound_lock(page); -#endif - return flags; -} - -static inline void compound_unlock_irqrestore(struct page *page, - unsigned long flags) -{ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - compound_unlock(page); - local_irq_restore(flags); -#endif -} - /* * The atomic page->_mapcount, starts from -1: so that transitions * both from it and to it can be tracked, using atomic_inc_and_test diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 91b7f9b2b774..74b7cece1dfa 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -106,9 +106,6 @@ enum pageflags { #ifdef CONFIG_MEMORY_FAILURE PG_hwpoison, /* hardware poisoned page. Don't touch */ #endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - PG_compound_lock, -#endif __NR_PAGEFLAGS, /* Filesystems */ @@ -683,12 +680,6 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) #define __PG_MLOCKED 0 #endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -#define __PG_COMPOUND_LOCK (1 << PG_compound_lock) -#else -#define __PG_COMPOUND_LOCK 0 -#endif - /* * Flags checked when a page is freed. Pages being freed should not have * these flags set. It they are, there is a problem. @@ -698,8 +689,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) 1 << PG_private | 1 << PG_private_2 | \ 1 << PG_writeback | 1 << PG_reserved | \ 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ - 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON | \ - __PG_COMPOUND_LOCK) + 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON ) /* * Flags checked when a page is prepped for return by the page allocator. diff --git a/mm/debug.c b/mm/debug.c index 3eb3ac2fcee7..9dfcd77e7354 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -45,9 +45,6 @@ static const struct trace_print_flags pageflag_names[] = { #ifdef CONFIG_MEMORY_FAILURE {1UL << PG_hwpoison, "hwpoison" }, #endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - {1UL << PG_compound_lock, "compound_lock" }, -#endif }; static void dump_flags(unsigned long flags, diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1c7c6bb69d3c..d0d862e4ca74 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2761,9 +2761,7 @@ struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr) /* * Because tail pages are not marked as "used", set it. We're under - * zone->lru_lock, 'splitting on pmd' and compound_lock. - * charge/uncharge will be never happen and move_account() is done under - * compound_lock(), so we don't have to take care of races. + * zone->lru_lock and migration entries setup in all page mappings. */ void mem_cgroup_split_huge_fixup(struct page *head) { @@ -4738,9 +4736,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma, * @from: mem_cgroup which the page is moved from. * @to: mem_cgroup which the page is moved to. @from != @to. * - * The caller must confirm following. - * - page is not on LRU (isolate_page() is useful.) - * - compound_lock is held when nr_pages > 1 + * The caller must make sure the page is not on LRU (isolate_page() is useful.) * * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" * from old cgroup. @@ -5061,8 +5057,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, struct page *page; /* - * We don't take compound_lock() here but no race with splitting thp - * happens because: + * No race with splitting thp happens because: * - if pmd_trans_huge_lock() returns 1, the relevant thp is not * under splitting, which means there's no concurrent thp split, * - if another thread runs into split_huge_page() just after we -- 2.1.4