Re: CONFIG_NO_HZ_FULL + CONFIG_PREEMPT_RT_FULL = nogo

From: Frederic Weisbecker <fweisbec@gmail.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Mike Galbraith <bitbucket@online.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	RT <linux-rt-users@vger.kernel.org>
Subject: Re: CONFIG_NO_HZ_FULL + CONFIG_PREEMPT_RT_FULL = nogo
Date: Fri, 8 Nov 2013 17:03:24 +0100	[thread overview]
Message-ID: <20131108160322.GB11112@localhost.localdomain> (raw)
In-Reply-To: <20131108144534.GE18245@linux.vnet.ibm.com>

On Fri, Nov 08, 2013 at 06:45:34AM -0800, Paul E. McKenney wrote:
> On Fri, Nov 08, 2013 at 03:29:38PM +0100, Frederic Weisbecker wrote:
> > On Fri, Nov 08, 2013 at 06:03:31AM -0800, Paul E. McKenney wrote:
> > > On Fri, Nov 08, 2013 at 02:26:28PM +0100, Mike Galbraith wrote:
> > > > On Fri, 2013-11-08 at 04:37 -0800, Paul E. McKenney wrote: 
> > > > > On Fri, Nov 08, 2013 at 08:31:20AM +0100, Mike Galbraith wrote:
> > > > > > On Thu, 2013-11-07 at 19:23 -0800, Paul E. McKenney wrote:
> > > > > > 
> > > > > > > An untested patch that gets rid of the RCU_SOFTIRQs in this case is below.
> > > > > > 
> > > > > > Yup, toasted.
> > > > > 
> > > > > You lost me on this one.  If my patch broke your system, any chance of
> > > > > any diagnostic information?
> > > > 
> > > > No no, the RCU_SOFTIRQs are toast, history, gone.
> > > 
> > > Ah, I do like that outcome much better!  ;-)  The scheduling-clock
> > > interrupts are gone (or at least reduced) as well?
> > > 
> > > And does this mean that I can have your Tested-by?
> > 
> > What's wrong with Toasted-by: ?  ;)
> 
> Does this mean that I can have your Toasted by?  ;-)

Sure that was assumed ;)