Date: Thu, 2 Apr 2015 12:08:33 -0400
From: Don Zickus <dzickus@redhat.com>
To: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>, Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrew Jones <drjones@redhat.com>,
        chai wen <chaiw.fnst@cn.fujitsu.com>,
        Ulrich Obergfell <uobergfe@redhat.com>,
        Fabian Frederick <fabf@skynet.be>, Aaron Tomlin <atomlin@redhat.com>,
        Ben Zhang <benzh@chromium.org>, Christoph Lameter <cl@linux.com>,
        Gilad Ben-Yossef <gilad@benyossef.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] watchdog: nohz: don't run watchdog on nohz_full cores
Message-ID: <20150402160833.GH175361@redhat.com>
References: <1427741465-15747-1-git-send-email-cmetcalf@ezchip.com>
 <20150331072502.GA16754@gmail.com>
 <551AE7D4.3020608@ezchip.com>
 <20150402133502.GA175361@redhat.com>
 <551D48F9.6090101@ezchip.com>
 <20150402141527.GD175361@redhat.com>
 <20150402153827.GC10357@lerouge>
 <551D6373.2030000@ezchip.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <551D6373.2030000@ezchip.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 938
Lines: 24

On Thu, Apr 02, 2015 at 11:42:43AM -0400, Chris Metcalf wrote:
> >
> >>Then perhaps as a debug aid, expose a /proc/sys/kernel/watchdog_cpumask for
> >>folks to modify in case they want to enable the watchdog on the nohz cpus.
> >That sounds like a good idea.
> 
> OK, I will respin v2 of the patch as follows:
> 
> - Provide a watchdog_cpumask as suggested by Don.
> - On a non-NO_HZ_FULL build, it defaults to cpu_possible as normal
> - On a NO_HZ_FULL build, it defaults to the housekeeping cpus
> - If the mask is modified, we disable and then re-enable the watchdog,
>   so that the watchdog init code can exit() the appropriate threads as
>   they start up

Sounds good. :-)

Cheers,
Don
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/