From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f176.google.com (mail-pd0-f176.google.com [209.85.192.176]) by kanga.kvack.org (Postfix) with ESMTP id 68D896B0032 for ; Mon, 7 Oct 2013 14:44:09 -0400 (EDT) Received: by mail-pd0-f176.google.com with SMTP id q10so7499700pdj.35 for ; Mon, 07 Oct 2013 11:44:09 -0700 (PDT) Message-ID: <525300EE.8020505@redhat.com> Date: Mon, 07 Oct 2013 14:43:58 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 27/63] mm: numa: Scan pages with elevated page_mapcount References: <1381141781-10992-1-git-send-email-mgorman@suse.de> <1381141781-10992-28-git-send-email-mgorman@suse.de> In-Reply-To: <1381141781-10992-28-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Peter Zijlstra , Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML On 10/07/2013 06:29 AM, Mel Gorman wrote: > Currently automatic NUMA balancing is unable to distinguish between false > shared versus private pages except by ignoring pages with an elevated > page_mapcount entirely. This avoids shared pages bouncing between the > nodes whose task is using them but that is ignored quite a lot of data. > > This patch kicks away the training wheels in preparation for adding support > for identifying shared/private pages is now in place. The ordering is so > that the impact of the shared/private detection can be easily measured. Note > that the patch does not migrate shared, file-backed within vmas marked > VM_EXEC as these are generally shared library pages. Migrating such pages > is not beneficial as there is an expectation they are read-shared between > caches and iTLB and iCache pressure is generally low. > > Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel -- All rights reversed -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756451Ab3JGSoR (ORCPT ); Mon, 7 Oct 2013 14:44:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32435 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752891Ab3JGSoQ (ORCPT ); Mon, 7 Oct 2013 14:44:16 -0400 Message-ID: <525300EE.8020505@redhat.com> Date: Mon, 07 Oct 2013 14:43:58 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Mel Gorman CC: Peter Zijlstra , Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML Subject: Re: [PATCH 27/63] mm: numa: Scan pages with elevated page_mapcount References: <1381141781-10992-1-git-send-email-mgorman@suse.de> <1381141781-10992-28-git-send-email-mgorman@suse.de> In-Reply-To: <1381141781-10992-28-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2013 06:29 AM, Mel Gorman wrote: > Currently automatic NUMA balancing is unable to distinguish between false > shared versus private pages except by ignoring pages with an elevated > page_mapcount entirely. This avoids shared pages bouncing between the > nodes whose task is using them but that is ignored quite a lot of data. > > This patch kicks away the training wheels in preparation for adding support > for identifying shared/private pages is now in place. The ordering is so > that the impact of the shared/private detection can be easily measured. Note > that the patch does not migrate shared, file-backed within vmas marked > VM_EXEC as these are generally shared library pages. Migrating such pages > is not beneficial as there is an expectation they are read-shared between > caches and iTLB and iCache pressure is generally low. > > Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel -- All rights reversed