Subject: Re: ipc-msg broken again on 3.11-rc7?

From: Manfred Spraul <[email-masked]>
Date: Tue, 03 Sep 2013 09:49:48 +0200

Hi Vineet,

On 09/03/2013 09:34 AM, Vineet Gupta wrote:
> However assuming we are going ahead with debugging this - can you 
> please confirm whether you see the issue on x86 as well as I have not 
> tested that ? I vaguely remember one of your earlier posts suggested 
> you did Thx, -Vineet 
I'm unable to reproduce the issue so far. I ran
- something like 4000 stock msgctl08 with 4 cores on x86.
- a few runs with modified msgctl08 with either slowed down reader or 
slowed down writer threads. (i.e.: force queue full or queue empty waits).
- a few runs (modified&unmodified) with all but one core taken offline.

I have not yet tested with PREEMPT enabled.

A few more ideas:
- what is the output of ipcs -q? Are the queues empty or full?
- what is the output of then WCHAN field with ps when it hangs?
Something like
/ #ps/ -o pid,f,stat,pcpu,pmem,psr,/wchan/=/WIDE/-/WCHAN/ -o comm,args

--
     Manfred