Re: [PATCH v9 2/3] watchdog: add watchdog_cpumask sysctl to assist nohz

From: Ulrich Obergfell
Date: Sat Apr 25 2015 - 11:43:58 EST

----- Original Message -----
From: "Don Zickus" <dzickus@xxxxxxxxxx>
> On Tue, Apr 21, 2015 at 10:07:00AM -0400, Ulrich Obergfell wrote:
>> Chris,
>> I think the user should only be allowed to specify a mask that is a subset of
>> tick_nohz_full_mask as only those CPUs don't have a watchdog thread by default.
>> In other words, the user should not be able to interfere with housekeeping CPUs.
> Hi Uli,
> I am not sure that is necessary. This was supposed to be a debugging
> interface for nohz (and possibly other technologies). I think restricting
> it to just tick_nohz makes it difficult to try out new things or debug
> certain problems.
> Personally, I feel anyone who will use this sys interface will need to do so
> at their own risk.
> Cheers,
> Don

Don, o.k. - I understand.

Chris, please ignore my idea to add a plausibility check.


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