Subject: Re: [PATCH] softirq: let ksoftirqd do its job

From: Peter Zijlstra <[email-masked]>
Date: Thu, 1 Sep 2016 13:53:56 +0200

On Thu, Sep 01, 2016 at 01:02:31PM +0200, Jesper Dangaard Brouer wrote:
>    PID  S  %CPU     TIME+  COMMAND
>      3  R  50.0  29:02.23  ksoftirqd/0
>  10881  R  10.7   1:01.61  udp_sink
>  10837  R  10.0   1:05.20  udp_sink
>  10852  S  10.0   1:01.78  udp_sink
>  10862  R  10.0   1:05.19  udp_sink
>  10844  S   9.7   1:01.91  udp_sink
> 
> This is strange, why is ksoftirqd/0 getting 50% of the CPU time???

Do you run your udp_sink thingy in a cpu-cgroup?