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

Thomas Gleixner
2023-12-15T20:31:44Z

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>