From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by e32.co.us.ibm.com (8.12.11.20060308/8.13.8) with ESMTP id lA9HKXmt031535 for ; Fri, 9 Nov 2007 12:20:33 -0500 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id lA9IL1mc023984 for ; Fri, 9 Nov 2007 11:21:03 -0700 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lA9IL0AQ029321 for ; Fri, 9 Nov 2007 11:21:01 -0700 Date: Fri, 9 Nov 2007 10:20:59 -0800 From: Nishanth Aravamudan Subject: Re: [PATCH 6/6] Use one zonelist that is filtered by nodemask Message-ID: <20071109182059.GJ7507@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> <20071109181607.GI7507@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071109181607.GI7507@us.ibm.com> Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: On 09.11.2007 [10:16:07 -0800], Nishanth Aravamudan wrote: > 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... Hrm, more importantly, isn't this an existing issue? Maybe should be resolved separately from the one zonelist patches. -Nish -- Nishanth Aravamudan IBM Linux Technology Center -- 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