From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Message-Id: <20070514173218.6787.56089.sendpatchset@skynet.skynet.ie> Subject: [PATCH 0/2] Two patches to address bug report in relation to high-order atomic allocations Date: Mon, 14 May 2007 18:32:18 +0100 (IST) Sender: owner-linux-mm@kvack.org Return-Path: To: nicolas.mailhot@laposte.net, apw@shadowen.org, clameter@sgi.com Cc: Mel Gorman , akpm@linux-foundation.org, linux-mm@kvack.org List-ID: The following two patches should address a problem reported at http://lkml.org/lkml/2007/5/10/550 . The issue was that atomic high-order allocations were failing even though free memory was available at the requested order. The first patch addresses an observation in the logs that the majority of free memory was at lower orders even though it was known that high-order allocations were regularly required. This patch informs kswapd that there is a known high-order that allocation will regularly request, triggering watermark reclaim at that order. Arguably, this minimum value that kswapd reclaims at should be PAGE_ALLOC_COSTLY_ORDER. The second patch addresses an issue where the callers ability to enter direct reclaim is not taken into account when checking watermarks. The patch alters zone_watermarks_ok() so that it only checks the watermarks at order-0 when the caller is flagged ALLOC_HIGH or ALLOC_HARDER. Nicolas, I would appreciate if you would test 2.6.21-mm2 with both of these patches applied. They have changed in a number of respects from what what I sent you over the weekend and I'd like to be sure the fix still works. Thanks -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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