From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 35AE86B0093 for ; Mon, 13 Dec 2010 21:34:13 -0500 (EST) Received: by iwn40 with SMTP id 40so194275iwn.14 for ; Mon, 13 Dec 2010 18:34:11 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20101214110711.af70b5b0.kamezawa.hiroyu@jp.fujitsu.com> References: <0724024711222476a0c8deadb5b366265b8e5824.1291568905.git.minchan.kim@gmail.com> <20101208170504.1750.A69D9226@jp.fujitsu.com> <87oc8wa063.fsf@gmail.com> <20101213153105.GA2344@barrios-desktop> <20101214110711.af70b5b0.kamezawa.hiroyu@jp.fujitsu.com> Date: Tue, 14 Dec 2010 11:34:11 +0900 Message-ID: Subject: Re: [PATCH v4 4/7] Reclaim invalidated page ASAP From: Minchan Kim Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Ben Gamari , KOSAKI Motohiro , Andrew Morton , Rik van Riel , linux-mm , LKML , Wu Fengguang , Johannes Weiner , Nick Piggin List-ID: On Tue, Dec 14, 2010 at 11:07 AM, KAMEZAWA Hiroyuki wrote: > On Tue, 14 Dec 2010 00:31:05 +0900 > Minchan Kim wrote: > >> Test Environment : >> DRAM : 2G, CPU : Intel(R) Core(TM)2 CPU >> Rsync backup directory size : 16G >> >> rsync version is 3.0.7. >> rsync patch is Ben's fadivse. >> stress scenario do following jobs with parallel. >> >> 1. make all -j4 linux, git clone linux-kernel >> 2. git clone linux-kernel >> 3. rsync src dst >> >> nrns : no-patched rsync + no stress >> prns : patched rsync + no stress >> nrs =A0: no-patched rsync + stress >> prs =A0: patched rsync + stress >> >> pginvalidate : the number of dirty/writeback pages which is invalidated = by fadvise >> pgreclaim : pages moved PG_reclaim trick in inactive's tail >> >> In summary, my patch enhances a littie bit about elapsed time in >> memory pressure environment and enhance reclaim effectivness(reclaim/rec= laim) >> with x2. It means reclaim latency is short and doesn't evict working set >> pages due to invalidated pages. >> >> Look at reclaim effectivness. Patched rsync enhances x2 about reclaim >> effectiveness and compared to mmotm-12-03, mmotm-12-03-fadvise enhances >> 3 minute about elapsed time in stress environment. >> I think it's due to reduce scanning, reclaim overhead. >> >> In no-stress enviroment, fadivse makes program little bit slow. >> I think because there are many pgfault. I don't know why it happens. >> Could you guess why it happens? >> >> Before futher work, I hope listen opinions. >> Any comment is welcome. >> > > At first, the improvement seems great. Thank you for your effort. Thanks, Kame. > >> In no-stress enviroment, fadivse makes program little bit slow. >> I think because there are many pgfault. I don't know why it happens. >> Could you guess why it happens? >> > > Are there no program which accesses a directory rsync'ed ? Maybe. some programs might have mmaped files. But although it happens, deactivate_page found that and it does nothing so the page can't be reclaimed. > > Thanks, > -Kame > > --=20 Kind regards, Minchan Kim -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org