From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Lehmann Subject: Re: write performance difference 3.18.21/4.2.1 Date: Fri, 25 Sep 2015 01:20:25 +0200 Message-ID: <20150924232025.GA2242@schmorp.de> References: <20150923215850.GC2360@schmorp.de> <20150923231103.GA3463@schmorp.de> <20150924182836.GD40291@jaegeuk-mac02> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZfFoZ-0004Fg-0r for linux-f2fs-devel@lists.sourceforge.net; Thu, 24 Sep 2015 23:20:35 +0000 Received: from mail.nethype.de ([5.9.56.24]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1ZfFoW-0006gA-Tp for linux-f2fs-devel@lists.sourceforge.net; Thu, 24 Sep 2015 23:20:35 +0000 Content-Disposition: inline In-Reply-To: <20150924182836.GD40291@jaegeuk-mac02> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net On Thu, Sep 24, 2015 at 11:28:36AM -0700, Jaegeuk Kim wrote: > > The log starts after only 20GB had been written. Here is the status output > > at 25GB: > > > > http://ue.tst.eu/734f7883107ee4dabff77602db92310b.txt > > It seems about 700MB were moved by background GC. And to quantify "slower", copying 2.1TiB took 18h, at 35.6MB/s. "sync" was routinely taking minutes to execute. As a sidenote, a "du" on cold cache pulled in data from the drive at ~26MB/s, which is quite impressive. At the number of files, that means it is pulling in ~4.4kb/stat. It also means it stat's at 5869 files/s, which is very good! I hadn't expected this from a flash file system on rotational media. > > Any idea why 4.2.1 performs so much worse than 3.8.21? > > One thing that we can try is to run the latest f2fs source in v3.18. > This branch supports f2fs for v3.18. Will do! > And, if possible, could you share the status output of both of v3.18 and v4.2? Will do, this is the output for 4.2.1, after copying and having it sit idle for a few hours. http://ue.tst.eu/90522477a480ae7a3b71647269b31ff7.txt -- The choice of a Deliantra, the free code+content MORPG -----==- _GNU_ http://www.deliantra.net ----==-- _ generation ---==---(_)__ __ ____ __ Marc Lehmann --==---/ / _ \/ // /\ \/ / schmorp@schmorp.de -=====/_/_//_/\_,_/ /_/\_\ ------------------------------------------------------------------------------