[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20160902103534.670b8f6a@redhat.com>
Date: Fri, 2 Sep 2016 10:35:34 +0200
From: Jesper Dangaard Brouer <brouer@...hat.com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Eric Dumazet <eric.dumazet@...il.com>,
David Miller <davem@...emloft.net>,
Rik van Riel <riel@...hat.com>,
Paolo Abeni <pabeni@...hat.com>,
Hannes Frederic Sowa <hannes@...hat.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
netdev <netdev@...r.kernel.org>,
Jonathan Corbet <corbet@....net>, brouer@...hat.com
Subject: Re: [PATCH] softirq: let ksoftirqd do its job
On Thu, 1 Sep 2016 17:28:02 +0200
Peter Zijlstra <peterz@...radead.org> wrote:
> On Thu, Sep 01, 2016 at 03:30:42PM +0200, Jesper Dangaard Brouer wrote:
> > Still... enabled!
> > Hmmm.. more idea how to disable this???
>
> I think you ought to be able to assign yourself to the root cgroup,
> something like:
>
> echo $$ > /cgroup/tasks
>
> or wheverever the cpu-cgroup controller is mounted at.
>
> But its been a fair while since I touched any of that, its not a CONFIG
> I have enabled much.
I could not figure out how to disable autogroups, so I ended up
compiling the kernel without CONFIG_SCHED_AUTOGROUP.
PID PR S %CPU TIME+ COMMAND
3 20 R 20.7 0:53.05 ksoftirqd/0
9299 20 R 16.3 0:03.62 udp_sink
9296 20 S 16.0 0:03.59 udp_sink
9297 20 R 16.0 0:03.58 udp_sink
9298 20 R 16.0 0:03.57 udp_sink
9295 20 R 15.3 0:03.43 udp_sink
Top new shows the CPU distribution is more correct, thus we can
concluded the artifact I saw was indeed caused by autogroup.
I can also confirm that my netperf UDP_STREAM tests now work again,
but I need around 32 parallel netperf to counter the effectiveness of
the ksoftirqd process. While I only need 5 udp_sink programs.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
Powered by blists - more mailing lists