From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756281Ab3JGRnP (ORCPT ); Mon, 7 Oct 2013 13:43:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43961 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753218Ab3JGRnO (ORCPT ); Mon, 7 Oct 2013 13:43:14 -0400 Message-ID: <5252F2A1.4040204@redhat.com> Date: Mon, 07 Oct 2013 13:42:57 -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 15/63] Revert "mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node" References: <1381141781-10992-1-git-send-email-mgorman@suse.de> <1381141781-10992-16-git-send-email-mgorman@suse.de> In-Reply-To: <1381141781-10992-16-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 06:28 AM, Mel Gorman wrote: > PTE scanning and NUMA hinting fault handling is expensive so commit > 5bca2303 ("mm: sched: numa: Delay PTE scanning until a task is scheduled > on a new node") deferred the PTE scan until a task had been scheduled on > another node. The problem is that in the purely shared memory case that > this may never happen and no NUMA hinting fault information will be > captured. We are not ruling out the possibility that something better > can be done here but for now, this patch needs to be reverted and depend > entirely on the scan_delay to avoid punishing short-lived processes. > > Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel -- All rights reversed From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f181.google.com (mail-pd0-f181.google.com [209.85.192.181]) by kanga.kvack.org (Postfix) with ESMTP id 869946B0032 for ; Mon, 7 Oct 2013 13:43:10 -0400 (EDT) Received: by mail-pd0-f181.google.com with SMTP id g10so7417739pdj.26 for ; Mon, 07 Oct 2013 10:43:10 -0700 (PDT) Message-ID: <5252F2A1.4040204@redhat.com> Date: Mon, 07 Oct 2013 13:42:57 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 15/63] Revert "mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node" References: <1381141781-10992-1-git-send-email-mgorman@suse.de> <1381141781-10992-16-git-send-email-mgorman@suse.de> In-Reply-To: <1381141781-10992-16-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 06:28 AM, Mel Gorman wrote: > PTE scanning and NUMA hinting fault handling is expensive so commit > 5bca2303 ("mm: sched: numa: Delay PTE scanning until a task is scheduled > on a new node") deferred the PTE scan until a task had been scheduled on > another node. The problem is that in the purely shared memory case that > this may never happen and no NUMA hinting fault information will be > captured. We are not ruling out the possibility that something better > can be done here but for now, this patch needs to be reverted and depend > entirely on the scan_delay to avoid punishing short-lived processes. > > 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