Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756064AbXKISQ0 (ORCPT ); Fri, 9 Nov 2007 13:16:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753867AbXKISQR (ORCPT ); Fri, 9 Nov 2007 13:16:17 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:57960 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbXKISQR (ORCPT ); Fri, 9 Nov 2007 13:16:17 -0500 Date: Fri, 9 Nov 2007 10:16:07 -0800 From: Nishanth Aravamudan To: Christoph Lameter Cc: Lee Schermerhorn , Mel Gorman , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rientjes@google.com, kamezawa.hiroyu@jp.fujitsu.com Subject: Re: [PATCH 6/6] Use one zonelist that is filtered by nodemask Message-ID: <20071109181607.GI7507@us.ibm.com> References: <20071109143226.23540.12907.sendpatchset@skynet.skynet.ie> <20071109143426.23540.44459.sendpatchset@skynet.skynet.ie> <20071109161455.GB32088@skynet.ie> <20071109164537.GG7507@us.ibm.com> <1194628732.5296.14.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux 2.6.24-rc1-gb55d1b18 (x86_64) User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1827 Lines: 44 On 09.11.2007 [09:26:01 -0800], Christoph Lameter wrote: > On Fri, 9 Nov 2007, Lee Schermerhorn wrote: > > > > On the other hand, if we call alloc_pages() with GFP_THISNODE set, there > > > is no nid to base the allocation on, so we "fallback" to numa_node_id() > > > [ almost like the nid had been specified as -1 ]. > > > > > > So I guess this is logical -- but I wonder, do we have any callers of > > > alloc_pages(GFP_THISNODE) ? It seems like an odd thing to do, when > > > alloc_pages_node() exists? > > > > I don't know if we have any current callers that do this, but absent any > > documentation specifying otherwise, Mel's implementation matches what > > I'd expect the behavior to be if I DID call alloc_pages with 'THISNODE. > > However, we could specify that THISNODE is ignored in __alloc_pages() > > and recommend the use of alloc_pages_node() passing numa_node_id() as > > the nid parameter to achieve the behavior. This would eliminate the > > check for 'THISNODE in __alloc_pages(). Just mask it off before calling > > down to __alloc_pages_internal(). > > > > Does this make sense? > > I like consistency. If someone absolutely wants a local page then > specifying GFP_THISNODE to __alloc_pages is okay. Leave as is I guess. Fair enough. > What happens though if an MPOL_BIND policy is in effect? The node used > must then be the nearest node from the policy mask.... Indeed, this probably needs to be validated... Sigh, more interleaving of policies and everything else... -Nish -- Nishanth Aravamudan IBM Linux Technology Center - 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/