From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 11 Jun 2007 11:40:48 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH v2] gfp.h: GFP_THISNODE can go to other nodes if some are unpopulated In-Reply-To: <1181586222.8324.78.camel@localhost> Message-ID: References: <20070607150425.GA15776@us.ibm.com> <20070607220149.GC15776@us.ibm.com> <466D44C6.6080105@shadowen.org> <1181586222.8324.78.camel@localhost> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Lee Schermerhorn Cc: Andy Whitcroft , Nishanth Aravamudan , ak@suse.de, anton@samba.org, mel@csn.ul.ie, akpm@linux-foundation.org, linux-mm@kvack.org List-ID: On Mon, 11 Jun 2007, Lee Schermerhorn wrote: > When the hugepages patch was evolving, I suggested that we might want to > export the "populated map" to applications so that they could ask to > bind to or interleave across only populated nodes. We never pursued > that. Maybe just eliminate nodes that are unpopulated in the "policy > zone" from the node masks for MPOL_BIND and MPOL_INTERLEAVE in the > system calls? Saves checking the populated node set in the allocation > paths. Would need appropriate error return if this resulted in empty > nodemask. That would work for the MPOL_BIND case since it has a zonelist. However, MPOL_INTERLEAVE does not have a zonelist. I think we need the populated map for interleave. The hacky way in how I checked for an unpopulated node in the patch just posted is not that effective. > Of course, memory hotplug could result in nodes becoming empty after the > nodemasks are adjusted, so we probably can't avoid checks in the > allocation paths if we want to avoid the bind and interleave issues you > mention above. Right. -- 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