Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755281AbZICNq6 (ORCPT ); Thu, 3 Sep 2009 09:46:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753290AbZICNq5 (ORCPT ); Thu, 3 Sep 2009 09:46:57 -0400 Received: from mail.tmr.com ([64.65.253.246]:48761 "EHLO partygirl.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753011AbZICNq5 (ORCPT ); Thu, 3 Sep 2009 09:46:57 -0400 Message-ID: <4A9FC8CE.3070005@tmr.com> Date: Thu, 03 Sep 2009 09:46:54 -0400 From: Bill Davidsen Organization: TMR Associates Inc, Schenectady NY User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.21) Gecko/20090507 Fedora/1.1.16-1.fc9 SeaMonkey/1.1.16 MIME-Version: 1.0 To: Adayadil Thomas CC: linux-kernel@vger.kernel.org Subject: Re: LowFree pattern References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; 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: 3089 Lines: 98 Adayadil Thomas wrote: >> What problem did you see that you traced to LowFree? >> > > I have set this device as a bridge. Higher latency and low throughput seem > to be related to LowFree. There are also packet drops at the interface > when LowFree is too low. > > I have another device which has 4G RAM split into 900M LowMem and > the rest as HighMem. In that case also, LowMem goes to a low level, say 8M > and although HighMem has ~2G free, the system gives OOPS (related to > page_alloc failures) > when acting as a bridge (passing packets). > > Then /proc/sys/vm tuning may help. > > > On Wed, Sep 2, 2009 at 3:22 PM, Bill Davidsen wrote: > >> Adayadil Thomas wrote: >> >>> Greetings. >>> >>> I am running a centos linux with 2.6.20 version kernel. The system has >>> 1G of RAM. >>> >>> As time goes by the LowFree becomes really low. Right now it shows >>> 137M .. but it goes as low as 8M or so >>> >>> The command - >>> echo 3 > /proc/sys/vm/drop_caches >>> brings back the LowFree to way up high. >>> >>> The question I have is whether the system by itself release the cache >>> (drop cache) automatically >>> to maintain a reasonable LowFree? >>> Is this configurable? >>> >>> >> You can change the parameters in /rpoc/sys/vm if you wish, but what makes >> you think this is needed? Cache is dropped as memory is needed, and >> drop_cache in general is a good way to slow the system. >> >> >>> Any information or help is much appreciated. >>> >>> >> What problem did you see that you traced to LowFree? >> >> >>> cat /proc/meminfo >>> MemTotal: 1034788 kB >>> MemFree: 138240 kB >>> Buffers: 99260 kB >>> Cached: 177776 kB >>> SwapCached: 51740 kB >>> Active: 605172 kB >>> Inactive: 113572 kB >>> HighTotal: 130720 kB >>> HighFree: 252 kB >>> LowTotal: 904068 kB >>> LowFree: 137988 kB >>> SwapTotal: 1048568 kB >>> SwapFree: 976332 kB >>> Dirty: 380 kB >>> Writeback: 0 kB >>> AnonPages: 441348 kB >>> Mapped: 15540 kB >>> Slab: 146088 kB >>> SReclaimable: 104288 kB >>> SUnreclaim: 41800 kB >>> PageTables: 1596 kB >>> NFS_Unstable: 0 kB >>> Bounce: 0 kB >>> CommitLimit: 1565960 kB >>> Committed_AS: 590576 kB >>> VmallocTotal: 114680 kB >>> VmallocUsed: 15052 kB >>> VmallocChunk: 99348 kB >>> -- bill davidsen CTO TMR Associates, Inc "Now we have another quarterback besides Kurt Warner telling us during postgame interviews that he owes every great thing that happens to him on a football field to his faith in Jesus. I knew there had to be a reason why the Almighty included a mute button on my remote." -- Arthur Troyer on Tim Tebow (Sports Illustrated) -- 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/