From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 2 Aug 2007 11:56:35 -0700 (PDT) From: Christoph Lameter Subject: Re: NUMA policy issues with ZONE_MOVABLE In-Reply-To: <20070802140904.GA16940@skynet.ie> Message-ID: References: <20070725111646.GA9098@skynet.ie> <20070802140904.GA16940@skynet.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: linux-mm@kvack.org, Lee Schermerhorn , ak@suse.de, KAMEZAWA Hiroyuki , akpm@linux-foundation.org, pj@sgi.com List-ID: On Thu, 2 Aug 2007, Mel Gorman wrote: > Hence the regression test is dependant on timing. The question is if the values > should always be up-to-date when read from userspace. I put together one patch > that would refresh the counters when numastat or vmstat was being read but it > requires a per-cpu function to be called. This may be undesirable as it would > be punishing on large systems running tools that frequently read /proc/vmstat > for example. Was it done this way on purpose? The comments around the stats > code would led me to believe this lag is on purpose to avoid per-cpu calls. The lag was introduced with the vm statistics rework since ZVCs use deferred updates. We could call refresh_vm_stats before handing out the counters? > The alternative was to apply this patch to numactl so that the > regression test waits on the timers to update. With this patch, the > regression tests passed on a 4-node x86_64 machine. Another possible solution. Andi: Which solution would you prefer? -- 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