Re: [PATCH 14/18] x86/resctrl: Add helpers for system wide mon/alloc capable

[James Morse]

Hello!

On 10/11/2022 10:51, Shaopeng Tan (Fujitsu) wrote:
>> resctrl reads rdt_alloc_capable or rdt_mon_capable to determine whether any
>> of the resources support the corresponding features.
>> resctrl also uses the static-keys that affect the architecture's context-switch
>> code to determine the same thing.
>>
>> This forces another architecture to have the same static-keys.
>>
>> As the static-key is enabled based on the capable flag, and none of the
>> filesystem uses of these are in the scheduler path, move the capable flags
>> behind helpers, and use these in the filesystem code instead of the static-key.
>>
>> After this change, only the architecture code manages and uses the static-keys
>> to ensure __resctrl_sched_in() does not need runtime checks.
>>
>> This avoids multiple architectures having to define the same static-keys.

> arch/x86/kernel/cpu/resctrl/rdtgroup.c
>  static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp)
>  {
>          if (rdt_mon_capable) 
>                  free_rmid(rgrp->closid, rgrp->mon.rmid);
>  }
> I think you forgot to fix rdt_mon_capable here.
> if (rdt_mon_capable) => if (resctrl_arch_mon_capable())

Yes - looks like I did.


Thanks!

James