Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755883Ab1DVBe1 (ORCPT ); Thu, 21 Apr 2011 21:34:27 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:56195 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755700Ab1DVBe0 (ORCPT ); Thu, 21 Apr 2011 21:34:26 -0400 From: John Stultz To: linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Dave Hansen , Mel Gorman , Andrew Morton , John Stultz Subject: [PATCH] mm: Check if any page in a pageblock is reserved before marking it MIGRATE_RESERVE Date: Thu, 21 Apr 2011 18:34:03 -0700 Message-Id: <1303436043-26644-1-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.3.2.146.gca209 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: 2218 Lines: 64 From: Arve Hjønnevåg 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. CC: Dave Hansen CC: Mel Gorman CC: Andrew Morton Signed-off-by: Arve Hjønnevåg Acked-by: Mel Gorman [This patch was submitted and acked a little over a year ago (see: http://lkml.org/lkml/2010/4/6/172 ), but never seemingly made it upstream. Resending for comments. -jstultz] Signed-off-by: John Stultz --- 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 ed87f3b..209d9bf 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3288,6 +3288,20 @@ 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 (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 @@ -3326,7 +3340,7 @@ 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); -- 1.7.3.2.146.gca209 -- 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/