Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Dec 2001 11:37:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Dec 2001 11:37:49 -0500 Received: from altus.drgw.net ([209.234.73.40]:17934 "EHLO altus.drgw.net") by vger.kernel.org with ESMTP id ; Fri, 21 Dec 2001 11:37:41 -0500 Date: Fri, 21 Dec 2001 10:29:40 -0600 From: Troy Benjegerdes To: =?iso-8859-1?Q?G=E9rard_Roudier?= Cc: Andre Hedrick , jlm , linux-kernel@vger.kernel.org Subject: Re: Poor performance during disk writes Message-ID: <20011221102940.W25200@altus.drgw.net> In-Reply-To: <20011218183059.L1832-100000@gerard> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.2.5i In-Reply-To: <20011218183059.L1832-100000@gerard>; from groudier@free.fr on Tue, Dec 18, 2001 at 06:42:49PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 18, 2001 at 06:42:49PM +0100, G?rard Roudier wrote: > > > On Tue, 18 Dec 2001, Andre Hedrick wrote: > > > File './Bonnie.2276', size: 1073741824, volumes: 1 > > Writing with putc()... done: 72692 kB/s 83.7 %CPU > > Rewriting... done: 25355 kB/s 12.0 %CPU > > Writing intelligently...done: 103022 kB/s 40.5 %CPU > > Reading with getc()... done: 37188 kB/s 67.5 %CPU > > Reading intelligently...done: 40809 kB/s 11.4 %CPU > > Seeker 2...Seeker 1...Seeker 3...start 'em...done...done...done... > > ---Sequential Output (nosync)--- ---Sequential Input-- --Rnd Seek- > > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --04k (03)- > > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > > 1*1024 72692 83.7 103022 40.5 25355 12.0 37188 67.5 40809 11.4 382.1 2.4 > > > > Maybe this is the kind of performance you want out your ATA subsystem. > > Maybe if I could get a patch in to the kernels we could all have stable > > and fast IO. > > I rather see lots of wasting rather than performance, here. Bonnie says > that your subsystem can sustain 103 MB/s write but only 41 MB/s read. This > looks about 60% throughput wasted for read. Uh, well, um, what drive is he writing too?? He could very well have 2 gig of memory in this box and half the writes were cached. 41MB/s seems reasonable for most common IDE disks. Of course I know Andre has some rather 'uncommon' IDE drives :P Does bonnie actually do any sort of 'sync' operation to ensure data writen is on the disk? Is that 100mb/sec write real, or just because of block layer caching? > > Note that if you intend to use it only for write-only applications, > performance are not that bad, even if just dropping the data on the floor > would give you infinite throughput without any difference in > functionnality. :-) > > > G?rard Roudier > Not CEO, not President of anything. > > > Regards, > > > > > > Andre Hedrick > > CEO/President, LAD Storage Consulting Group > > Linux ATA Development > > Linux Disk Certification Project > > - > 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/ > -- Troy Benjegerdes | master of mispeeling | 'da hozer' | hozer@drgw.net -----"If this message isn't misspelled, I didn't write it" -- Me ----- "Why do musicians compose symphonies and poets write poems? They do it because life wouldn't have any meaning for them if they didn't. That's why I draw cartoons. It's my life." -- Charles Schulz - 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/