Re: [PATCH v8 01/24] tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef

James Morse
2024-01-22T18:05:25Z

Hi Thomas,

On 15/12/2023 20:31, Thomas Gleixner wrote:
> On Fri, Dec 15 2023 at 17:43, James Morse wrote:
>> tick_nohz_full_mask lists the CPUs that are nohz_full. This is only
>> needed when CONFIG_NO_HZ_FULL is defined. tick_nohz_full_cpu() allows
>> a specific CPU to be tested against the mask, and evaluates to false
>> when CONFIG_NO_HZ_FULL is not defined.
>>
>> The resctrl code needs to pick a CPU to run some work on, a new helper
>> prefers housekeeping CPUs by examining the tick_nohz_full_mask. Hiding
>> the declaration behind #ifdef CONFIG_NO_HZ_FULL forces all the users to
>> be behind an ifdef too.
>>
>> Move the tick_nohz_full_mask declaration, this lets callers drop the
>> ifdef, and guard access to tick_nohz_full_mask with IS_ENABLED() or
>> something like tick_nohz_full_cpu().
>>
>> The definition does not need to be moved as any callers should be
>> removed at compile time unless CONFIG_NO_HZ_FULL is defined.

> I can pick that up separately, but I'm fine when it goes with the
> resctrl lot. For that case:

> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Thanks!

James