lkml.org 
[lkml]   [2007]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch] CFS scheduler, -v18

    * Willy Tarreau <w@1wt.eu> wrote:

    > Today I had a little time to try CFS again (last time it was -v9!). I
    > ran it on top of 2.6.20.14, and simply tried ocbench again. You
    > remember ? With -v9, I ran 64 processes which all progressed very
    > smoothly. With -v18, it's not the case anymore. When I run 64
    > processes, only 7 of them show smooth rounds, while all the other ones
    > are only updated once a second. Sometimes they only progress by one
    > iteration, sometimes by a full round. Some are even updated once ever
    > 2 seconds, because if I drag an xterm above them and quickly remove
    > it, the xterm leaves a trace there for up to 2 seconds.
    >
    > Also, only one of my 2 CPUs is used. I see the rq vary between 1 and
    > 5, with a permanent 50% idle... :
    >
    > procs memory swap io system cpu
    > r b w swpd free buff cache si so bi bo in cs us sy id
    > 1 0 0 0 874400 7864 90436 0 0 0 0 279 2204 50 0 50
    > 3 0 0 0 874408 7864 90436 0 0 0 0 273 2122 50 1 50
    > 1 0 0 0 874408 7864 90436 0 0 0 0 253 1660 49 1 50
    > 3 0 0 0 874408 7864 90436 0 0 0 0 252 1977 50 0 50
    > 2 0 0 0 874408 7864 90436 0 0 0 0 253 2274 49 1 50
    > 3 0 0 0 874408 7864 90436 0 0 0 0 252 1846 49 1 50
    > 1 0 0 0 874408 7864 90436 0 0 0 0 339 1782 49 1 50
    >
    > I have no idea about what version brought that unexpected behaviour,
    > but it's clearly something which needs to be tracked down.

    hm, the two problems might be related. Could you try v17 perhaps? In v18
    i have 'unified' all the sched.c's between the various kernel releases,
    maybe that brought in something unexpected on 2.6.20.14. (perhaps try
    v2.6.21.5 based cfs too?)

    > My scheduler is at 250 Hz, and here are the values I found in
    > /proc/sys/kernel:

    could you send me the file the cfs-debug-info.sh script produced. You
    can pick the script up from:

    http://people.redhat.com/mingo/cfs-scheduler/tools/cfs-debug-info.sh

    (i'd suggest to send it in private mail, output is large and detailed.
    If your kernel has no /proc/config.gz then please send me your .config
    file too.)

    Ingo
    -
    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/

    \
     
     \ /
      Last update: 2007-06-24 17:55    [W:5.066 / U:0.236 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site