Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754899Ab0DFDKG (ORCPT ); Mon, 5 Apr 2010 23:10:06 -0400 Received: from qw-out-2122.google.com ([74.125.92.24]:14143 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115Ab0DFDJ6 (ORCPT ); Mon, 5 Apr 2010 23:09:58 -0400 From: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= To: Mel Gorman Cc: KOSAKI Motohiro , TAO HU , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Ye Yuan.Bo-A22116" , Chang Qing-A21550 , linux-arm-kernel@lists.infradead.org, =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= Subject: [PATCH] mm: Check if any page in a pageblock is reserved before marking it MIGRATE_RESERVE Date: Mon, 5 Apr 2010 20:09:16 -0700 Message-Id: <1270523356-1728-1-git-send-email-arve@android.com> X-Mailer: git-send-email 1.6.5.1 In-Reply-To: <20100405101424.GA21207@csn.ul.ie> References: <20100405101424.GA21207@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1802 Lines: 52 This fixes a problem where the first pageblock got marked MIGRATE_RESERVE even though it only had a few free pages. This in turn caused no contiguous memory to be reserved and frequent kswapd wakeups that emptied the caches to get more contiguous memory. Signed-off-by: Arve Hjønnevåg --- mm/page_alloc.c | 16 +++++++++++++++- 1 files changed, 15 insertions(+), 1 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fb7df1d..46ade16 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2860,6 +2860,20 @@ static inline unsigned long wait_table_bits(unsigned long size) #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) /* + * Check if a pageblock contains reserved pages + */ +static int pageblock_is_reserved(unsigned long start_pfn) +{ + unsigned long end_pfn = start_pfn + pageblock_nr_pages; + unsigned long pfn; + + for (pfn = start_pfn; pfn < end_pfn; pfn++) + if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) + return 1; + return 0; +} + +/* * Mark a number of pageblocks as MIGRATE_RESERVE. The number * of blocks reserved is based on min_wmark_pages(zone). The memory within * the reserve will tend to store contiguous free pages. Setting min_free_kbytes @@ -2898,7 +2912,7 @@ static void setup_zone_migrate_reserve(struct zone *zone) continue; /* Blocks with reserved pages will never free, skip them. */ - if (PageReserved(page)) + if (pageblock_is_reserved(pfn)) continue; block_migratetype = get_pageblock_migratetype(page); -- 1.6.5.1 -- 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/