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

From: Sedat Dilek <sedat.dilek@gmail.com>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Davidlohr Bueso <dave.bueso@gmail.com>,
	Davidlohr Bueso <davidlohr.bueso@hp.com>,
	linux-next <linux-next@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mm <linux-mm@kvack.org>, Andi Kleen <andi@firstfloor.org>,
	Rik van Riel <riel@redhat.com>,
	Jonathan Gonzalez <jgonzalez@linets.cl>
Subject: Re: ipc-msg broken again on 3.11-rc7?
Date: Tue, 3 Sep 2013 10:43:29 +0200	[thread overview]
Message-ID: <CA+icZUWPHR5Kkd_s1DyK+0jXAh8SobGjW_qeqUMrY4cSwkQmHQ@mail.gmail.com> (raw)
In-Reply-To: <5225949C.9030201@colorfullife.com>

On Tue, Sep 3, 2013 at 9:49 AM, Manfred Spraul <manfred@colorfullife.com> wrote:
> 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.
>

Cool.
Manfred, can you offer your modified test-cases, please?
Thanks in advance.

- Sedat -

> 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