From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx163.postini.com [74.125.245.163]) by kanga.kvack.org (Postfix) with SMTP id 0B9EE6B0033 for ; Wed, 3 Jul 2013 14:35:52 -0400 (EDT) Date: Wed, 3 Jul 2013 20:35:17 +0200 From: Peter Zijlstra Subject: Re: [PATCH 12/13] mm: numa: Scan pages with elevated page_mapcount Message-ID: <20130703183517.GC18898@dyad.programming.kicks-ass.net> References: <1372861300-9973-1-git-send-email-mgorman@suse.de> <1372861300-9973-13-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1372861300-9973-13-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML On Wed, Jul 03, 2013 at 03:21:39PM +0100, Mel Gorman wrote: > Initial support for automatic NUMA balancing was unable to distinguish > between false shared versus private pages except by ignoring pages with an > elevated page_mapcount entirely. This patch kicks away the training wheels > as initial support for identifying shared/private pages is now in place. > Note that the patch still leaves shared, file-backed in VM_EXEC vmas in > place guessing that these are shared library pages. Migrating them are > likely to be of major benefit as generally the expectation would be that > these are read-shared between caches and that iTLB and iCache pressure is > generally low. This reminds me; there a clause in task_numa_work() that skips 'small' VMAs. I don't see the point of that. In fact; when using things like electric fence this might mean skipping most memory. -- 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