Re: [PATCH v9 22/31] x86/resctrl: Handle domain creation/deletion for RDT_RESOURCE_PERF_PKG

[Reinette Chatre <reinette.chatre@intel.com>]

Hi Tony,

On 8/29/25 12:33 PM, Tony Luck wrote:



> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index 8986071dd72a..b054c7cd13f1 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -75,6 +75,14 @@ static inline struct rdt_hw_l3_mon_domain *resctrl_to_arch_mon_dom(struct rdt_l3
>  	return container_of(r, struct rdt_hw_l3_mon_domain, d_resctrl);
>  }
>  
> +/**
> + * struct rdt_perf_pkg_mon_domain - CPUs sharing an package scoped resctrl monitor resource
> + * @hdr:	common header for different domain types
> + */
> +struct rdt_perf_pkg_mon_domain {
> +	struct rdt_domain_hdr   hdr;

Please use tabs to align struct member names.

> +};
> +
>  /**
>   * struct msr_param - set a range of MSRs from a domain
>   * @res:       The resource to use
> @@ -174,6 +182,8 @@ bool intel_aet_get_events(void);
>  void __exit intel_aet_exit(void);
>  int intel_aet_read_event(int domid, int rmid, enum resctrl_event_id evtid,
>  			 void *arch_priv, u64 *val);
> +void intel_aet_setup_mon_domain(int cpu, int id, struct rdt_resource *r,
> +				struct list_head *add_pos);
>  #else
>  static inline bool intel_aet_get_events(void) { return false; }
>  static inline void __exit intel_aet_exit(void) { }
> @@ -182,6 +192,9 @@ static inline int intel_aet_read_event(int domid, int rmid, enum resctrl_event_i
>  {
>  	return -EINVAL;
>  }
> +
> +static inline void intel_aet_setup_mon_domain(int cpu, int id, struct rdt_resource *r,
> +					      struct list_head *add_pos) { }
>  #endif
>  
>  #endif /* _ASM_X86_RESCTRL_INTERNAL_H */
> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
> index 039a00c58514..5745c6979293 100644
> --- a/arch/x86/kernel/cpu/resctrl/core.c
> +++ b/arch/x86/kernel/cpu/resctrl/core.c
> @@ -574,6 +574,9 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
>  	case RDT_RESOURCE_L3:
>  		l3_mon_domain_setup(cpu, id, r, add_pos);
>  		break;
> +	case RDT_RESOURCE_PERF_PKG:
> +		intel_aet_setup_mon_domain(cpu, id, r, add_pos);

This can easily be consistent with existing naming (l3_mon_domain_setup()),
intel_aet_setup_mon_domain() -> intel_aet_mon_domain_setup()?

> +		break;
>  	default:
>  		pr_warn_once("Unknown resource rid=%d\n", r->rid);
>  		break;
> @@ -671,6 +674,15 @@ static void domain_remove_cpu_mon(int cpu, struct rdt_resource *r)
>  		synchronize_rcu();
>  		l3_mon_domain_free(hw_dom);
>  		break;
> +	case RDT_RESOURCE_PERF_PKG:
> +		if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_PERF_PKG))
> +			return;
> +
> +		resctrl_offline_mon_domain(r, hdr);

As mentioned earlier I think that including changes to resctrl_offline_mon_domain() to
support being called with RDT_RESOURCE_PERF_PKG as part of this patch will be much easier
to follow than sneaking it in with the L3 refactoring.

> +		list_del_rcu(&hdr->list);
> +		synchronize_rcu();
> +		kfree(container_of(hdr, struct rdt_perf_pkg_mon_domain, hdr));
> +		break;
>  	default:
>  		pr_warn_once("Unknown resource rid=%d\n", r->rid);
>  		break;
> diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c
> index 9239740e9647..71aed96f9499 100644
> --- a/arch/x86/kernel/cpu/resctrl/intel_aet.c
> +++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c
> @@ -255,3 +255,27 @@ int intel_aet_read_event(int domid, int rmid, enum resctrl_event_id eventid,
>  
>  	return valid ? 0 : -EINVAL;
>  }
> +
> +void intel_aet_setup_mon_domain(int cpu, int id, struct rdt_resource *r,
> +				struct list_head *add_pos)
> +{
> +	struct rdt_perf_pkg_mon_domain *d;
> +	int err;
> +
> +	d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu));
> +	if (!d)
> +		return;
> +
> +	d->hdr.id = id;
> +	d->hdr.type = RESCTRL_MON_DOMAIN;
> +	d->hdr.rid = r->rid;
> +	cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
> +	list_add_tail_rcu(&d->hdr.list, add_pos);
> +
> +	err = resctrl_online_mon_domain(r, &d->hdr);

Same with the resctrl_online_mon_domain() changes.

> +	if (err) {
> +		list_del_rcu(&d->hdr.list);
> +		synchronize_rcu();
> +		kfree(d);
> +	}
> +}

Reinette