lkml.org 
[lkml]   [2007]   [Sep]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Network slowdown due to CFS

* Martin Michlmayr <tbm@cyrius.com> wrote:

> * Mike Galbraith <efault@gmx.de> [2007-09-26 12:23]:
> > I noticed on the iperf website a patch which contains sched_yield().
> > http://dast.nlanr.net/Projects/Iperf2.0/patch-iperf-linux-2.6.21.txt
> >
> > Do you have that patch applied by any chance? If so, it might be a
> > worth while to try it without it.
>
> Yes, this patch was applied. When I revert it, I get the same (high)
> performance with both kernels.

great! Could you try this too:

echo 1 > /proc/sys/kernel/sched_compat_yield
does it fix iperf performance too (with the yield patch applied to
iperf)?

I think the real fix would be for iperf to use blocking network IO
though, or maybe to use a POSIX mutex or POSIX semaphores.

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: 2007-09-26 13:25    [from the cache]
©2003-2011 Jasper Spaans