Re: [PATCH v2 16/23] sched/cache: Introduce sched_cache_present to enable cache aware scheduling for multi LLCs NUMA node

[Peter Zijlstra]

On Wed, Dec 03, 2025 at 03:07:35PM -0800, Tim Chen wrote:
> From: Chen Yu <yu.c.chen@xxxxxxxxx>
> 
> Cache-aware load balancing should only be enabled if there are more
> than 1 LLCs within 1 NUMA node. sched_cache_present is introduced to
> indicate whether this platform supports this topology.
> 
> Suggested-by: Libo Chen <libo.chen@xxxxxxxxxx>
> Suggested-by: Adam Li <adamli@xxxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
> ---
> 
> Notes:
>     v1->v2:
>     	Use flag sched_cache_present to indicate whether a platform
>     	supports cache aware scheduling. Change this flag from staic key.
>     	There should be only 1 static key to control the cache aware
>     	scheduling. (Peter Zijlstra)
> 
>  kernel/sched/topology.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index d583399fc6a1..9799e3a9a609 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -24,6 +24,8 @@ int max_llcs;
>  
>  #ifdef CONFIG_SCHED_CACHE
>  
> +static bool sched_cache_present;

sched_energy_present
sched_asym_cpucapacity
sched_cluster_active
sched_smt_present

are all static keys tied to the current topology, why break the streak
and make this a boolean?