Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964858AbWAZUl2 (ORCPT ); Thu, 26 Jan 2006 15:41:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964868AbWAZUl2 (ORCPT ); Thu, 26 Jan 2006 15:41:28 -0500 Received: from mail.zelnet.ru ([80.92.97.13]:31172 "EHLO mail.zelnet.ru") by vger.kernel.org with ESMTP id S964858AbWAZUl1 (ORCPT ); Thu, 26 Jan 2006 15:41:27 -0500 Message-ID: <43D933EB.6080009@namesys.com> Date: Thu, 26 Jan 2006 23:41:15 +0300 From: Edward Shishkin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.7) Gecko/20050414 X-Accept-Language: en-us, en, ru MIME-Version: 1.0 To: Jens Axboe CC: Hans Reiser , LKML , Reiserfs mail-list Subject: Re: random minor benchmark: Re: Copy 20 tarfiles: ext2 vs (reiser4, unixfile) vs (reiser4,cryptcompress) References: <43D7C6BE.1010804@namesys.com> <43D7CA7F.4010502@namesys.com> <20060126153343.GH4311@suse.de> <43D91225.3030605@namesys.com> <20060126185612.GM4311@suse.de> In-Reply-To: <20060126185612.GM4311@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1963 Lines: 83 Jens Axboe wrote: >On Thu, Jan 26 2006, Edward Shishkin wrote: > > >>Jens Axboe wrote: >> >> >> >>>On Wed, Jan 25 2006, Hans Reiser wrote: >>> >>> >>> >>> >>>>Notice how CPU speed (and number of cpus) completely determines >>>>compression performance. >>>> >>>>cryptcompress refers to the reiser4 compression plugin, (unix file) >>>>refers to the reiser4 non-compressing plugin. >>>> >>>>Edward Shishkin wrote: >>>> >>>> >>>> >>>> >>>> >>>>>Here are the tests that vs asked for: >>>>>Creation (dd) of 20 tarfiles (the original 200M file is in ramfs) >>>>>Kernel: 2.6.15-mm4 + current git snapshot of reiser4 >>>>> >>>>>------------------------------------------ >>>>> >>>>>Laputa workstation >>>>>Uni Intel Pentium 4 (2.26 GHz) 512M RAM >>>>> >>>>>ext2: >>>>>real 2m, 15s >>>>>sys 0m, 14s >>>>> >>>>>reiser4(unix file) >>>>>real 2m, 7s >>>>>sys 0m, 23s >>>>> >>>>>reiser4(cryptcompress, lzo1, 64K) >>>>>real 2m, 13s >>>>>sys 0m, 11s >>>>> >>>>> >>>>> >>>>> >>>Just curious - does your crypt plugin reside in user space? >>> >>> >>> >>> >>> >>Nop. >>This is just wrappers for linux crypto api, zlib, etc.. >>so user time is zero and not interesting. >> >> > >Then why is the sys time lower than the "plain" writes on ext2 and >reiser4? Surely compressing isn't for free, yet the sys time is lower on >the compression write than the others. > > > I guess this is because real compression is going in background flush, not in sys_write->write_cryptcompress (which just copies user's data to page cache). So in this case we have something very similar to ext2. Reiser4 plain write (write_unix_file) is more complex, and currently we try to reduce its sys time. Edward. - 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/