Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158Ab0KCLm3 (ORCPT ); Wed, 3 Nov 2010 07:42:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13669 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752877Ab0KCLm1 (ORCPT ); Wed, 3 Nov 2010 07:42:27 -0400 Message-ID: <4CD14A6F.4010109@redhat.com> Date: Wed, 03 Nov 2010 07:41:35 -0400 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: Mandeep Singh Baines , KOSAKI Motohiro , Andrew Morton , Mel Gorman , Johannes Weiner , linux-kernel@vger.kernel.org, linux-mm@kvack.org, wad@chromium.org, olofj@chromium.org, hughd@chromium.org Subject: Re: [PATCH] RFC: vmscan: add min_filelist_kbytes sysctl for protecting the working set References: <20101028191523.GA14972@google.com> <20101101012322.605C.A69D9226@jp.fujitsu.com> <20101101182416.GB31189@google.com> <4CCF0BE3.2090700@redhat.com> <4CCF8151.3010202@redhat.com> <4CD0C22B.2000905@redhat.com> 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: 1129 Lines: 31 On 11/02/2010 11:03 PM, Minchan Kim wrote: > It could. > But time based approach would be same, IMHO. > First of all, I don't want long latency of direct reclaim process. > It could affect response of foreground process directly. > > If VM limits the number of pages reclaimed per second, direct reclaim > process's latency will be affected. so we should avoid throttling in > direct reclaim path. Agree? The idea would be to not throttle the processes trying to reclaim page cache pages, but to only reclaim anonymous pages when the page cache pages are low (and occasionally a few page cache pages, say 128 a second). If too many reclaimers come in when the page cache is low and no swap is available, we will OOM kill instead of stalling. After all, the entire point of this patch would be to avoid minutes-long latencies in triggering the OOM killer. -- 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/