[lkml]   [2007]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch] CFS scheduler, -v18

* Willy Tarreau <> wrote:

> Ingo,
> I've accidentally discovered a problem with -v18.
> Some time ago, I wrote a small program to prevent my laptop from
> entering low-power mode, and noticed that after upgrading my laptop's
> kernel from to, it completely
> freezes if I run this program.
> The program is trivial, it just sets its prio to nice +20 and forks a
> busy loop. I've added the ability to stop the loop after a
> user-definable number of iterations, and I can confirm that it
> unfreezes when the loop ends. I'm not even root when I run it.

hm, i tried your test-app and it causes no problems here. (which is not
a surprise - your app starts a nice +19 busy loop, which is one of the
common tests i do here too.)

To further debug this, could you try to create a 'high priority shell'
on a text console (i.e. not under X) that is SCHED_FIFO prio 98?
Something like:

chrt -f -p 98 $$

should do the trick. And then run this script:

before the test, during the test and after the test, from the high-prio
shell session. (the shell runs at SCHED_FIFO, so the expectation would
be for that it will be able to run during the test too) Then please send
me the resulting 3 debug files. Thanks,

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-07-01 10:35    [W:0.258 / U:3.512 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site