Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 3 Dec 2001 21:55:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 3 Dec 2001 18:48:37 -0500 Received: from perninha.conectiva.com.br ([200.250.58.156]:63504 "HELO perninha.conectiva.com.br") by vger.kernel.org with SMTP id ; Mon, 3 Dec 2001 15:39:06 -0500 Date: Mon, 3 Dec 2001 17:22:16 -0200 (BRST) From: Marcelo Tosatti To: Jason Holmes Cc: linux-kernel@vger.kernel.org Subject: Re: IO degradation in 2.4.17-pre2 vs. 2.4.16 In-Reply-To: <3C092CAB.4D1541F4@psu.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jason, Yes, throughtput-only tests will have their numbers degradated with the change applied on 2.4.16-pre2. The whole thing is just about tradeoffs: Interactivity vs throughtput. I'm not going to destroy interactivity for end users to get beatiful dbench numbers. And about your clients: Don't you think they want some kind of decent latency on their side? Anyway, thanks for your report! On Sat, 1 Dec 2001, Jason Holmes wrote: > I saw in a previous thread that the interactivity improvements in > 2.4.17-pre2 had some adverse effect on IO throughput and since I was > already evaluating 2.4.16 for a somewhat large fileserving project, I > threw 2.4.17-pre2 on to see what has changed. Throughput while serving > a large number of clients is important to me, so my tests have included > using dbench to try to see how things scale as clients increase. > > 2.4.16: > > Throughput 116.098 MB/sec (NB=145.123 MB/sec 1160.98 MBit/sec) 1 procs > Throughput 206.604 MB/sec (NB=258.255 MB/sec 2066.04 MBit/sec) 2 procs > Throughput 210.364 MB/sec (NB=262.955 MB/sec 2103.64 MBit/sec) 4 procs > Throughput 213.397 MB/sec (NB=266.747 MB/sec 2133.97 MBit/sec) 8 procs > Throughput 210.989 MB/sec (NB=263.736 MB/sec 2109.89 MBit/sec) 16 > procs > Throughput 138.713 MB/sec (NB=173.391 MB/sec 1387.13 MBit/sec) 32 > procs > Throughput 117.729 MB/sec (NB=147.162 MB/sec 1177.29 MBit/sec) 64 > procs > Throughput 66.7354 MB/sec (NB=83.4193 MB/sec 667.354 MBit/sec) 128 > procs > > 2.4.17-pre2: > > Throughput 96.2302 MB/sec (NB=120.288 MB/sec 962.302 MBit/sec) 1 procs > Throughput 226.679 MB/sec (NB=283.349 MB/sec 2266.79 MBit/sec) 2 procs > Throughput 223.955 MB/sec (NB=279.944 MB/sec 2239.55 MBit/sec) 4 procs > Throughput 224.533 MB/sec (NB=280.666 MB/sec 2245.33 MBit/sec) 8 procs > Throughput 153.672 MB/sec (NB=192.09 MB/sec 1536.72 MBit/sec) 16 procs > Throughput 91.3464 MB/sec (NB=114.183 MB/sec 913.464 MBit/sec) 32 > procs > Throughput 64.876 MB/sec (NB=81.095 MB/sec 648.76 MBit/sec) 64 procs > Throughput 54.9774 MB/sec (NB=68.7217 MB/sec 549.774 MBit/sec) 128 > procs > > Throughput 136.522 MB/sec (NB=170.652 MB/sec 1365.22 MBit/sec) 1 procs > Throughput 223.682 MB/sec (NB=279.603 MB/sec 2236.82 MBit/sec) 2 procs > Throughput 222.806 MB/sec (NB=278.507 MB/sec 2228.06 MBit/sec) 4 procs > Throughput 224.427 MB/sec (NB=280.534 MB/sec 2244.27 MBit/sec) 8 procs > Throughput 152.286 MB/sec (NB=190.358 MB/sec 1522.86 MBit/sec) 16 > procs > Throughput 92.044 MB/sec (NB=115.055 MB/sec 920.44 MBit/sec) 32 procs > Throughput 78.0881 MB/sec (NB=97.6101 MB/sec 780.881 MBit/sec) 64 > procs > Throughput 66.1573 MB/sec (NB=82.6966 MB/sec 661.573 MBit/sec) 128 > procs > > Throughput 117.95 MB/sec (NB=147.438 MB/sec 1179.5 MBit/sec) 1 procs > Throughput 212.469 MB/sec (NB=265.586 MB/sec 2124.69 MBit/sec) 2 procs > Throughput 214.763 MB/sec (NB=268.453 MB/sec 2147.63 MBit/sec) 4 procs > Throughput 214.007 MB/sec (NB=267.509 MB/sec 2140.07 MBit/sec) 8 procs > Throughput 96.6572 MB/sec (NB=120.821 MB/sec 966.572 MBit/sec) 16 > procs > Throughput 48.1342 MB/sec (NB=60.1677 MB/sec 481.342 MBit/sec) 32 > procs > Throughput 71.3444 MB/sec (NB=89.1806 MB/sec 713.444 MBit/sec) 64 > procs > Throughput 59.258 MB/sec (NB=74.0724 MB/sec 592.58 MBit/sec) 128 procs > > I have included three runs for 2.4.17-pre2 to show how inconsistent its > results are; 2.4.16 didn't have this problem to this extent. bonnie++ > numbers seem largely unchanged between kernels, coming in around: > > ------Sequential Output------ --Sequential Input- --Random- > -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- > Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP > 2512M 14348 81 49495 26 24438 16 16040 96 55006 15 373.7 1 > ------Sequential Create------ --------Random Create-------- > -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- > files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP > 16 3087 99 +++++ +++ +++++ +++ 3175 100 +++++ +++ 11042 100 > > The test machine is an IBM 342 with 2 1.26 GHz P3 processors and 1.25 GB > of RAM. The above numbers were generated off of 1 10K RPM SCSI disk > hanging off of an Adaptec aix7899 controller. > > -- > Jason Holmes > - > 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/ > - 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/