Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761488AbZCPR5k (ORCPT ); Mon, 16 Mar 2009 13:57:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757954AbZCPRvi (ORCPT ); Mon, 16 Mar 2009 13:51:38 -0400 Received: from gir.skynet.ie ([193.1.99.77]:51230 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757143AbZCPRvf (ORCPT ); Mon, 16 Mar 2009 13:51:35 -0400 From: Mel Gorman To: Mel Gorman , Linux Memory Management List Cc: Pekka Enberg , Rik van Riel , KOSAKI Motohiro , Christoph Lameter , Johannes Weiner , Nick Piggin , Linux Kernel Mailing List , Lin Ming , Zhang Yanmin , Peter Zijlstra Subject: [PATCH 18/27] Do not disable interrupts in free_page_mlock() Date: Mon, 16 Mar 2009 17:53:32 +0000 Message-Id: <1237226020-14057-19-git-send-email-mel@csn.ul.ie> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <1237226020-14057-1-git-send-email-mel@csn.ul.ie> References: <1237226020-14057-1-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3258 Lines: 96 free_page_mlock() tests and clears PG_mlocked using locked versions of the bit operations. If set, it disables interrupts to update counters and this happens on every page free even though interrupts are disabled very shortly afterwards a second time. This is wasteful. This patch splits what free_page_mlock() does. The bit check is still made. However, the update of counters is delayed until the interrupts are disabled and the non-lock version for clearing the bit is used. One potential weirdness with this split is that the counters do not get updated if the bad_page() check is triggered but a system showing bad pages is getting screwed already. Signed-off-by: Mel Gorman --- mm/internal.h | 11 +++-------- mm/page_alloc.c | 8 +++++++- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 478223b..7f775a1 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -155,14 +155,9 @@ static inline void mlock_migrate_page(struct page *newpage, struct page *page) */ static inline void free_page_mlock(struct page *page) { - if (unlikely(TestClearPageMlocked(page))) { - unsigned long flags; - - local_irq_save(flags); - __dec_zone_page_state(page, NR_MLOCK); - __count_vm_event(UNEVICTABLE_MLOCKFREED); - local_irq_restore(flags); - } + __ClearPageMlocked(page); + __dec_zone_page_state(page, NR_MLOCK); + __count_vm_event(UNEVICTABLE_MLOCKFREED); } #else /* CONFIG_UNEVICTABLE_LRU */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 349c64d..c4eb295 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -498,7 +498,6 @@ static inline void __free_one_page(struct page *page, static inline int free_pages_check(struct page *page) { - free_page_mlock(page); if (unlikely(page_mapcount(page) | (page->mapping != NULL) | (page_count(page) != 0) | @@ -555,6 +554,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) unsigned long flags; int i; int bad = 0; + int clearMlocked = PageMlocked(page); for (i = 0 ; i < (1 << order) ; ++i) bad += free_pages_check(page + i); @@ -570,6 +570,8 @@ static void __free_pages_ok(struct page *page, unsigned int order) kernel_map_pages(page, 1 << order, 0); local_irq_save(flags); + if (unlikely(clearMlocked)) + free_page_mlock(page); __count_vm_events(PGFREE, 1 << order); free_one_page(page_zone(page), page, order, get_pageblock_migratetype(page)); @@ -1020,6 +1022,7 @@ static void free_hot_cold_page(struct page *page, int cold) struct zone *zone = page_zone(page); struct per_cpu_pages *pcp; unsigned long flags; + int clearMlocked = PageMlocked(page); if (PageAnon(page)) page->mapping = NULL; @@ -1035,7 +1038,10 @@ static void free_hot_cold_page(struct page *page, int cold) pcp = &zone_pcp(zone, get_cpu())->pcp; local_irq_save(flags); + if (unlikely(clearMlocked)) + free_page_mlock(page); __count_vm_event(PGFREE); + if (cold) list_add_tail(&page->lru, &pcp->list); else -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/