From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933243Ab1D0QLD (ORCPT ); Wed, 27 Apr 2011 12:11:03 -0400 Received: from cantor.suse.de ([195.135.220.2]:47386 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933127Ab1D0QIS (ORCPT ); Wed, 27 Apr 2011 12:08:18 -0400 From: Mel Gorman To: Linux-MM , Linux-Netdev Cc: LKML , David Miller , Neil Brown , Peter Zijlstra , Mel Gorman Subject: [PATCH 05/13] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Date: Wed, 27 Apr 2011 17:08:03 +0100 Message-Id: <1303920491-25302-6-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.3.4 In-Reply-To: <1303920491-25302-1-git-send-email-mgorman@suse.de> References: <1303920491-25302-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The reserve is proportionally distributed over all !highmem zones in the system. So we need to allow an emergency allocation access to all zones. In order to do that we need to break out of any mempolicy boundaries we might have. In my opinion that does not break mempolicies as those are user oriented and not system oriented. That is, system allocations are not guaranteed to be within mempolicy boundaries. For instance IRQs don't even have a mempolicy. So breaking out of mempolicy boundaries for 'rare' emergency allocations, which are always system allocations (as opposed to user) is ok. Signed-off-by: Peter Zijlstra Signed-off-by: Mel Gorman --- mm/page_alloc.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7e7d9ce..5ff1f71 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2085,6 +2085,13 @@ restart: rebalance: /* Allocate without watermarks if the context allows */ if (alloc_flags & ALLOC_NO_WATERMARKS) { + /* + * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds + * the allocation is high priority and these type of + * allocations are system rather than user orientated + */ + zonelist = node_zonelist(numa_node_id(), gfp_mask); + page = __alloc_pages_high_priority(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); -- 1.7.3.4