Re: Network slowdown due to CFS

From: Martin Michlmayr
Date: Wed Sep 26 2007 - 07:29:50 EST

* Ingo Molnar <mingo@xxxxxxx> [2007-09-26 13:21]:
> > > I noticed on the iperf website a patch which contains sched_yield().
> > >
> 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)?

Yes, this gives me good performance too.

> 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.

So it's definitely not a bug in the kernel, only in iperf?

(CCing Stephen Hemminger who wrote the iperf patch.)
Martin Michlmayr
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