Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752530AbZIUAVz (ORCPT ); Sun, 20 Sep 2009 20:21:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751085AbZIUAVx (ORCPT ); Sun, 20 Sep 2009 20:21:53 -0400 Received: from mail-yw0-f173.google.com ([209.85.211.173]:48433 "EHLO mail-yw0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbZIUAVw (ORCPT ); Sun, 20 Sep 2009 20:21:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=mPyPrLWf5lfvxHcentwr4VyCvmMALrspOdo6L6QAPskUX9SqbncvDgPfHJ3nW8hE6M JAJmG8khP6avvt5T9iF/ibs61MVE5JvGWPwgQohyeAE/4MPuQQVvt3Z6zwxWJWWs9Cx/ bni6ZvneHrSbjyDyjzu4FqaaL3dpVFV1H8Hio= Message-ID: <4AB6C73C.1030004@gmail.com> Date: Sun, 20 Sep 2009 17:22:20 -0700 From: "Justin P. Mattock" User-Agent: Spicebird/0.7.1 (X11; 2009022519) MIME-Version: 1.0 To: Mike Galbraith CC: Ulrich Lukas , Linux Kernel Mailing List Subject: Re: Poor desktop responsiveness with background I/O-operations References: <4AB59CBB.8090907@datenparkplatz.de> <20090920080728.73bfe2a1@infradead.org> <4AB5ECD0.7010903@datenparkplatz.de> <1253475521.9224.43.camel@marge.simson.net> In-Reply-To: <1253475521.9224.43.camel@marge.simson.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3451 Lines: 91 Mike Galbraith wrote: > On Sun, 2009-09-20 at 10:50 +0200, Ulrich Lukas wrote: > >> Arjan van de Ven wrote: >> >>> can you try the following two things? >>> >>> echo 4096> /sys/block/sda/queue/nr_requests >>> for i in `pidof kjournald` ; do ionice -c1 -p $i ; done >>> >> I tried this just now, but it doesn't change things much. I can do a >> more testing later today. >> > > Try ionice -c3 for your dd. > > >>> I assume you're using CFQ. >>> >> Yes, it's CFQ. (see .config of my previous posting) >> >> Filesystem is EXT4. >> > > Mine is ext3. > > I can easily reproduce pain. The attached cheezy test script, when run > back to back with no args (stock IO), regularly produces beauties: > > Performance counter stats for 'sh -c konsole -e exit': > > 257.670601 task-clock-msecs # 0.004 CPUs > 1036 context-switches # 0.004 M/sec > 30 CPU-migrations # 0.000 M/sec > 6317 page-faults # 0.025 M/sec > 471734719 cycles # 1830.767 M/sec > 393365060 instructions # 0.834 IPC > 7849464 cache-references # 30.463 M/sec > 1038976 cache-misses # 4.032 M/sec > > 65.766937233 seconds time elapsed > > Yup, a full minute to get a binary loaded and fired up. Seems it and > others get evicted by the VM. Getting whatever back into ram is painful > to listen to (poor disk/me.. seek latency eating MUCH time). > > Calling script back to back with args 1 (realtime foreground) 3 (idle > background) does best: > > Performance counter stats for 'sh -c konsole -e exit': > > 169.915036 task-clock-msecs # 0.077 CPUs > 439 context-switches # 0.003 M/sec > 9 CPU-migrations # 0.000 M/sec > 6314 page-faults # 0.037 M/sec > 363128252 cycles # 2137.117 M/sec > 367410945 instructions # 1.012 IPC > 5822302 cache-references # 34.266 M/sec > 437189 cache-misses # 2.573 M/sec > > 2.213079979 seconds time elapsed > > Args 2 (best effort foreground) and 3 (idle background); > > Performance counter stats for 'sh -c konsole -e exit': > > 176.689856 task-clock-msecs # 0.015 CPUs > 357 context-switches # 0.002 M/sec > 15 CPU-migrations # 0.000 M/sec > 6314 page-faults # 0.036 M/sec > 374861947 cycles # 2121.582 M/sec > 368929476 instructions # 0.984 IPC > 5806286 cache-references # 32.861 M/sec > 496651 cache-misses # 2.811 M/sec > > 12.036165968 seconds time elapsed > > -Mike > Wow, at first I did not notice anything from your *.sh script, but then a few moments later, the system became vary sluggish. firefox takes about 15 seconds to load. OS is mint linux with the latest HEAD on an imac9,1. Justin P. Mattock -- 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/