From: Dave Jones <davej@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: RCU_USER_QS traces.
Date: Fri, 5 Oct 2012 16:00:30 -0400 [thread overview]
Message-ID: <20121005200030.GA1615@redhat.com> (raw)
In-Reply-To: <20121005123609.GA13172@somewhere>
On Fri, Oct 05, 2012 at 02:36:19PM +0200, Frederic Weisbecker wrote:
> On Thu, Oct 04, 2012 at 10:41:06AM -0400, Dave Jones wrote:
> > > We have CONFIG_RCU_USER_QS that is a specific case. It's an intermediate state
> > > before we implement a true CONFIG_NO_HZ_FULL. But the option is useless on its
> > > own for users. Worse, it introduces a real overhead. OTOH we want it to be upstream
> > > to make the development of full tickless feature more incremental.
> >
> > I couldn't resist trying it.. Did these get reported yet ?
>
> Hi Dave,
>
> Thanks for this report. I need to find the source of the issue.
>
> If you don't mind, could you please apply the following patch? You'll also
> need to enable:
>
> - CONFIG_EVENT_TRACING and CONFIG_RCU_TRACE
>
> And you also need this boot parameter:
>
> - trace_event=rcu_dyntick
>
> Thanks a lot!
Hrmph, it seems to have gone into hiding. I can't reproduce it any more.
If it shows about again, I'll get back to you.
Dave
prev parent reply other threads:[~2012-10-05 20:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-04 14:41 RCU_USER_QS traces Dave Jones
2012-10-04 15:46 ` Paul E. McKenney
2012-10-05 12:36 ` Frederic Weisbecker
2012-10-05 20:00 ` Dave Jones [this message]
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