Re: [PATCH 2/3] sched/fair: Use HK_TYPE_SCHED housekeeping CPUs

[Waiman Long]

On 9/3/24 09:12, Frederic Weisbecker wrote:
> Le Sun, Aug 18, 2024 at 07:45:19PM -0400, Waiman Long a écrit :
> > As the previous commit has enabled the setting of HK_TYPE_SCHED
> > housekeeping CPUs in nohz_full setup, we can now use the more aptly
> > named HK_TYPE_SCHED housekeeping CPUs instead of HK_TYPE_MISC.
> >
> > Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
> Can we instead merge HK_FLAG_TICK, HK_FLAG_WQ, HK_FLAG_TIMER, HK_FLAG_RCU,
> HK_FLAG_MISC and HK_FLAG_KTHREAD into a single
> HK_FLAG_KERNEL_NOISE / HK_TYPE_KERNEL_NOISE ?

Sure. I am open to new name as I am not good on that. 
HK_FLAG_KERNEL_NOISE does make sense.

Cheers,
Longman

> Thanks.
>
> > ---
> >   kernel/sched/fair.c | 7 ++-----
> >   1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index 6be618110885..0350667f5ce8 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -12128,16 +12128,13 @@ static inline int on_null_domain(struct rq *rq)
> >    * - When one of the busy CPUs notices that there may be an idle rebalancing
> >    *   needed, they will kick the idle load balancer, which then does idle
> >    *   load balancing for all the idle CPUs.
> > - *
> > - * - HK_TYPE_MISC CPUs are used for this task, because HK_TYPE_SCHED is not set
> > - *   anywhere yet.
> >    */
> >   static inline int find_new_ilb(void)
> >   {
> >   	const struct cpumask *hk_mask;
> >   	int ilb_cpu;
> >   
> > -	hk_mask = housekeeping_cpumask(HK_TYPE_MISC);
> > +	hk_mask = housekeeping_cpumask(HK_TYPE_SCHED);
> >   
> >   	for_each_cpu_and(ilb_cpu, nohz.idle_cpus_mask, hk_mask) {
> >   
> > @@ -12155,7 +12152,7 @@ static inline int find_new_ilb(void)
> >    * Kick a CPU to do the NOHZ balancing, if it is time for it, via a cross-CPU
> >    * SMP function call (IPI).
> >    *
> > - * We pick the first idle CPU in the HK_TYPE_MISC housekeeping set (if there is one).
> > + * We pick the first idle CPU in the HK_TYPE_SCHED housekeeping set (if there is one).
> >    */
> >   static void kick_ilb(unsigned int flags)
> >   {
> > --
> > 2.43.5