Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756120Ab0KVBSZ (ORCPT ); Sun, 21 Nov 2010 20:18:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58096 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754879Ab0KVBSY (ORCPT ); Sun, 21 Nov 2010 20:18:24 -0500 Message-ID: <4CE9C4A9.3040406@redhat.com> Date: Sun, 21 Nov 2010 20:17:29 -0500 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.8) Gecko/20100806 Fedora/3.1.2-1.fc13 Lightning/1.0b2pre Thunderbird/3.1.2 MIME-Version: 1.0 To: Minchan Kim CC: Andrew Morton , linux-mm , LKML , Peter Zijlstra , KOSAKI Motohiro , Johannes Weiner , Nick Piggin Subject: Re: [RFC 1/2] deactive invalidated pages References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1372 Lines: 33 On 11/21/2010 09:30 AM, Minchan Kim wrote: > Recently, there are reported problem about thrashing. > (http://marc.info/?l=rsync&m=128885034930933&w=2) > It happens by backup workloads(ex, nightly rsync). > That's because the workload makes just use-once pages > and touches pages twice. It promotes the page into > active list so that it results in working set page eviction. > > Some app developer want to support POSIX_FADV_NOREUSE. > But other OSes don't support it, either. > (http://marc.info/?l=linux-mm&m=128928979512086&w=2) > > By Other approach, app developer uses POSIX_FADV_DONTNEED. > But it has a problem. If kernel meets page is writing > during invalidate_mapping_pages, it can't work. > It is very hard for application programmer to use it. > Because they always have to sync data before calling > fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could > be discardable. At last, they can't use deferred write of kernel > so that they could see performance loss. > (http://insights.oetiker.ch/linux/fadvise.html) This looks promising... Acked-by: Rik van Riel -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/