lkml.org 
[lkml]   [2007]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Interesting interaction between lguest and CFS

* Rusty Russell <rusty@rustcorp.com.au> wrote:

> This sounds like the waker process (nice 19) not getting a chance to
> run. You can hack around it for the moment by changing "nice(19)" in
> Documentation/lguest/lguest.c to something less aggressive.

even if the waker runs at nice+19, under CFS (which schedules
deterministically) it should not be delayed by a single nice-0 task by
more than ~70 msecs. That is a far cry from the 'seconds' that Matt saw
- and the sched stats he sent look anomalous too. Also, i'm not able to
reproduce it at all - while any nice+19 related problem should be
readily reproducable on my box too. So my current take is that this is
some sort of host-side CFS related problem and that the lguest host
threads somehow were the first ones that managed to trigger it in some
really bad way.

OTOH i do agree with your patch, that nice+19 thing is quite hacky :-)

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: 2007-06-05 09:13    [W:0.836 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site