From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 0EB61600034 for ; Thu, 1 Oct 2009 09:26:05 -0400 (EDT) From: Suresh Jayaraman Subject: [09/31] mm: system wide ALLOC_NO_WATERMARK Date: Thu, 1 Oct 2009 19:36:20 +0530 Message-Id: <1254405980-15976-1-git-send-email-sjayaraman@suse.de> Sender: owner-linux-mm@kvack.org To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: netdev@vger.kernel.org, Neil Brown , Miklos Szeredi , Wouter Verhelst , Peter Zijlstra , trond.myklebust@fys.uio.no, Suresh Jayaraman List-ID: From: Peter Zijlstra 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: Suresh Jayaraman --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) Index: mmotm/mm/page_alloc.c =================================================================== --- mmotm.orig/mm/page_alloc.c +++ mmotm/mm/page_alloc.c @@ -1775,6 +1775,11 @@ restart: rebalance: /* Allocate without watermarks if the context allows */ if (alloc_flags & ALLOC_NO_WATERMARKS) { + /* + * break out mempolicy boundaries + */ + zonelist = node_zonelist(numa_node_id(), gfp_mask); + page = __alloc_pages_high_priority(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); -- 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