Re: [PATCH] watchdog: nohz: don't run watchdog on nohz_full cores

Chris Metcalf
2015-03-31T18:32:25Z

On 03/30/2015 10:04 PM, Mike Galbraith wrote:
> On Mon, Mar 30, 2015 at 02:51:05PM -0400, cmetcalf@ezchip.com wrote:
>> From: Chris Metcalf <cmetcalf@ezchip.com>
>>
>> Running watchdog can be a helpful debugging feature on regular
>> cores, but it's incompatible with nohz_full, since it forces
>> regular scheduling events. Accordingly, just exit out immediately
>> from any nohz_full core.
> Hm, I don't see why this is needed, for debugging/testing you turn it
> on, when you set up for critical operation, you turn it off.

It can be helpful to keep the watchdog running even in production
to help diagnose hard-to-reproduce failures. You just can't have it
running on the nohz_full cores.

--
Chris Metcalf, EZChip Semiconductor