From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 089A76B01EF for ; Mon, 5 Apr 2010 23:09:59 -0400 (EDT) Received: by qyk33 with SMTP id 33so4950024qyk.28 for ; Mon, 05 Apr 2010 20:09:57 -0700 (PDT) From: =?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> 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: owner-linux-mm@kvack.org 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?= List-ID: 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 HjA,nnevAJPYg --- 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, 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