Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 17 Jul 2002 16:03:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 17 Jul 2002 16:03:10 -0400 Received: from [195.223.140.120] ([195.223.140.120]:28530 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Wed, 17 Jul 2002 16:03:08 -0400 Date: Wed, 17 Jul 2002 22:05:35 +0200 From: Andrea Arcangeli To: mgross Cc: "Griffiths, Richard A" , "'Andrew Morton'" , "'Marcelo Tosatti'" , "'linux-kernel@vger.kernel.org'" , "'Carter K. George'" , "'Don Norton'" , "'James S. Tybur'" , "Gross, Mark" Subject: Re: fsync fixes for 2.4 Message-ID: <20020717200535.GP19553@dualathlon.random> References: <01BDB7EEF8D4D3119D95009027AE99951B0E6428@fmsmsx33.fm.intel.com> <20020715100719.GE34@dualathlon.random> <200207171735.g6HHZUP28835@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200207171735.g6HHZUP28835@unix-os.sc.intel.com> User-Agent: Mutt/1.3.27i X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2718 Lines: 61 On Wed, Jul 17, 2002 at 10:44:18AM -0400, mgross wrote: > On Monday 15 July 2002 06:07 am, Andrea Arcangeli wrote: > > On Fri, Jul 12, 2002 at 02:52:11PM -0700, Griffiths, Richard A wrote: > > >?Mark is off climbing Mt. Hood, so he asked me to post the data on the > > > fsync patch. > > I was excited to report the significant improvement of 2.4.19rc1+fsync fix > over 2.4.18 and didn't realize that the improvement was not due to the fsync > patch. I'm so glad Richard did a careful check, I was on my way out the > door for my vacation :) > > I would like to know what's so good about 2.4.19rc1 that gives our block I/O > benchmark that significant improvement over 2.4.18. that should be the effect of the first part of my vm updates that gone into 2.4.19pre. > > >?It appears from these results that there is no appreciable improvement > > > using the > > >?fsync patch - there is a slight loss of top end on 4 adapters 1 drive. > > > > that's very much expected, as said with my new design by adding an > > additional pass (third pass), I could remove the slight loss that I > > expected from the simple patch that puts wait_on_buffer right in the > > first pass. > > > > I mentioned this in my first email of the thread, so it looks all right. > > For a rc2 the slight loss sounds like the simplest approch. > > > > If you care about it, with my new fsync accounting design we can fix it, > > just let me know if you're interested about it. Personally I'm pretty > > much fine with it this way too, as said in the first email if we block > > it's likely bdflush is pumping the queue for us. the slowdown is most > > probably due too early unplug of the queue generated by the blocking > > points. > > I don't care about the very slight (and possibly in the noise floor of our > test) reduction in throughput due to the fsync fix. I think your's and > Andrews' assertion of the bdflush / dirty page handling getting stopped up > is likely the problem preventing scaling to my personal goal of 250 to > 300MB/sec on our setup. yep, should be. Actually running multiple fsyncs from multiple tasks will kind of workaround the single threaded async flushing of 2.4. > > Thanks, > > Mark Gross > PS I had a very nice time on mount hood. I didn't make it to the top this > time too much snow had melted off the top of the thing to have a safe attempt > at the summit. It was a guided (http://www.timberlinemtguides.com) 3 day > climb. :) Andrea - 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/