Messages in this thread | | | Date | Tue, 26 Oct 2010 19:00:11 +0600 | Subject | Fwd: 2.6.36 io bring the system to its knees | From | Aidar Kultayev <> |
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"And yes, we'd very much like to fix such slowdowns via heuristics as well (detecting large sequential IO and not letting it poison the existing cache), so good bugreports and reproducing testcases sent to linux-kernel@vger.kernel.org and people willing to try out experimental kernel patches would definitely be welcome.
Thanks,
Ingo"*
*from http://ask.slashdot.org/story/10/10/23/1828251/The-State-of-Linux-IO-Scheduling-For-the-Desktop#commentlisting
I'll be rather quick & to the point here.
I get & run stable kernels the same day they appear on kernel.org in hope to get away from these annoying, ignored, neglected slowdowns.
.config attached - I have Lenovo ThinkPad T400, Core2Duo T9400, 4Gb DDR2, w/integrated GM45, iwlagn for the intel 5300 wifi, CFS, ext2 for swap partition, ext3 for boot, ext4 for everything else. All the hardware I have runs linux natively. No kernel helped me from the days of 2.6.28.x upto 2.6.36. The dubbed slowdown fixes never worked for me. The kernel config choices are rather typical : NO_HZ, I don't go for 1000Hz and use 100 or 250Hz and voluntary preemption. Regarding the userland: Love choices, hence nothing but Gentoo + KDE4. Multilib. Some relevant info here:
============================================================================================== emerge --info Portage 2.1.8.3 (default/linux/amd64/10.0/desktop, gcc-4.5.1, glibc-2.11.2-r0, 2.6.36 x86_64) ================================================================= System uname: Linux-2.6.36-x86_64-Intel-R-_Core-TM-2_Duo_CPU_T9400_@_2.53GHz-with-gentoo-1.12.13 Timestamp of tree: Tue, 26 Oct 2010 10:30:01 +0000 app-shells/bash: 4.1_p7 dev-java/java-config: 2.1.11 dev-lang/python: 2.5.4-r4, 2.6.5-r3, 3.1.2-r4 dev-util/cmake: 2.8.1-r2 sys-apps/baselayout: 1.12.13 sys-apps/sandbox: 2.3-r1 sys-devel/autoconf: 2.13, 2.65-r1 sys-devel/automake: 1.7.9-r1, 1.8.5-r4, 1.9.6-r3, 1.10.3, 1.11.1 sys-devel/binutils: 2.20.1-r1 sys-devel/gcc: 4.5.1 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.10 sys-devel/make: 3.81-r2 CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -pipe -march=native" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/X11/xkb /usr/share/config /var/lib/hsqldb" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/php/apache2-php5/ext-active/ /etc/php/cgi-php5/ext-active/ /etc/php/cli-php5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -pipe -march=native" ==============================================================================================
Now, I know, Ingo said he wants : "good bugreports and reproducing testcases" and my testcase is very real life and rather replicates my typical use of computer these days:
- VirtualBox running XP only to look at some 2007 ppts ( the Ooo3 doens't cut it ) - JuK ( or VLC ) KDE's music player - some music in the background - Chromium browser, with bunch of tabs with J2EE/J2SE javadocs, eats out some significant swap space - bash terminals - ktorrent - PDFs opened in okular, Adobe reader - sync'ing portage tree & emerging new ebuilds - Netbeans, Eclipse, apache, vsftd, sshd, tomcat and the whole 9 yards.
How do I notice slowdowns ? The JuK lags so badly that it can't play any music, VBox running XP usually trashes the disk, the mouse pointer freezes, kwin effects freeze for few seconds. How can I make it much worse ? I can try & run disk clean up under XP that is running in VBox, with folder compression. On top of it if I start copying big files in linux ( 700MB avis, etc ), GUI effects freeze, mouse pointer freezes for few seconds sometimes.
And this is on 2.6.36 that is supposed to cure these "features". From this perspective, 2.6.36 is no better than any previous stable kernel I've tried. Two threads copying the same big file ( 700Mb avi ) to different folders, PLUS couple of "dd if=/dev/zero of=test.10g bs=1M count=10000" lead to the same freezing sound/pointer/WM effects.
best, Aidar PS: and yes, I do follow the problem here : https://bugzilla.kernel.org/show_bug.cgi?id=12309 This is a monumental failure for kernel development project and FLOSS in general. Poor management, no leadership/championship, no responsibility, neglect. It all shows why you can't rely on community driven project or projects. Fact. If you deny this, you are not truthful with yourself. This might be in one of the Harvard Business Case studies. Just think about what would happen if this gets embedded into some kind of pacesetter...
PS: I am a huge adept of FLOSS. I really think that RMS, GNU, Linus and many others got it right. But it is a shame to have this "feature" for so long with so many people affected and yet, neglected. [unhandled content-type:image/png][unhandled content-type:application/octet-stream][unhandled content-type:application/x-wine-extension-ini] | |