Re: [PATCH v10 2/3] watchdog: add watchdog_cpumask sysctl to assist nohz

[Don Zickus <dzickus@redhat.com>]

On Thu, Apr 30, 2015 at 04:09:52PM -0400, Chris Metcalf wrote:
> On 04/30/2015 04:00 PM, Don Zickus wrote:
> >On Thu, Apr 30, 2015 at 03:39:25PM -0400, Chris Metcalf wrote:
> >>  		if (err)
> >>  			pr_err("Failed to create watchdog threads, disabled\n");
> >>+		else {
> >>+			if (smpboot_update_cpumask_percpu_thread(
> >>+				    &watchdog_threads, &watchdog_cpumask))
> >>+				pr_err("Failed to set cpumask for watchdog threads\n");
> >Stupid nitpick, this error message tells us the 'watchdog' threads caused
> >the cpumask failure, but ....
> >
> >>+			/*
> >>+			 * Failure would be due to being unable to allocate
> >>+			 * a temporary cpumask, so we are likely not in a
> >>+			 * position to do much else to make things better.
> >>+			 */
> >>+			if (smpboot_update_cpumask_percpu_thread(
> >>+				    &watchdog_threads, &watchdog_cpumask) != 0)
> >>+				pr_err("cpumask update failed\n");
> >This one does not. :-(  If there is a respin, I would suggest copying the
> >above message down here.
> 
> There is that "#define pr_fmt(fmt)" at the top of the file that prefixes
> all the messages with "NMI watchdog: ", though.  I think that's
> sufficient to make it clear what the second message is about.
> (The first message I wrote the way I did to be parallel with the
> message just before it, if the thread creation failed.)

Ah, yes.  Nevermind.  I keep forgetting about that. :-)

Cheers,
Don