Re: [PATCH v1 13/31] x86/resctrl: Stop using the for_each_*_rdt_resource() walkers

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

Hi James,

On 3/21/2024 9:50 AM, James Morse wrote:
> The for_each_*_rdt_resource() helpers walk the architectures array

architecture's ?

> of structures, using the resctrl visible part as an iterator. These
> became over-complex when the structures were split into a
> filesystem and architecture-specific struct. This approach avoided
> the need to touch every call site.
> 
> Once the filesystem parts of resctrl are moved to /fs/, both the
> architecture's resource array, and the definition of those structures
> is no longer accessible. To support resctrl, each architecture would
> have to provide equally complex macros.
> 
> Change the resctrl code that uses these to walk through the resource_level
> enum and check the mon/alloc capable flags instead. Instances in core.c,
> and resctrl_arch_reset_resources() remain part of x86's architecture
> specific code.
> 
> Signed-off-by: James Morse <james.morse@arm.com>
> ---
>  arch/x86/kernel/cpu/resctrl/pseudo_lock.c |  7 +++++-
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c    | 30 +++++++++++++++++++----
>  2 files changed, 31 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> index 884b88e25141..f2315a50ea4f 100644
> --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> @@ -840,6 +840,7 @@ bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, unsigned long cbm
>  bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d)
>  {
>  	cpumask_var_t cpu_with_psl;
> +	enum resctrl_res_level i;
>  	struct rdt_resource *r;
>  	struct rdt_domain *d_i;
>  	bool ret = false;
> @@ -854,7 +855,11 @@ bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d)
>  	 * First determine which cpus have pseudo-locked regions
>  	 * associated with them.
>  	 */
> -	for_each_alloc_capable_rdt_resource(r) {
> +	for (i = 0; i < RDT_NUM_RESOURCES; i++) {
> +		r = resctrl_arch_get_resource(i);
> +		if (!r->alloc_capable)
> +			continue;
> +
>  		list_for_each_entry(d_i, &r->domains, list) {
>  			if (d_i->plr)
>  				cpumask_or(cpu_with_psl, cpu_with_psl,
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index e736e4d20f63..3f16e7854411 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -98,12 +98,17 @@ void rdt_last_cmd_printf(const char *fmt, ...)
>  
>  void rdt_staged_configs_clear(void)
>  {
> +	enum resctrl_res_level i;
>  	struct rdt_resource *r;
>  	struct rdt_domain *dom;
>  
>  	lockdep_assert_held(&rdtgroup_mutex);
>  
> -	for_each_alloc_capable_rdt_resource(r) {
> +	for (i = 0; i < RDT_NUM_RESOURCES; i++) {
> +		r = resctrl_arch_get_resource(i);
> +		if (!r->alloc_capable)
> +			continue;
> +
>  		list_for_each_entry(dom, &r->domains, list)
>  			memset(dom->staged_config, 0, sizeof(dom->staged_config));
>  	}
> @@ -2181,6 +2186,7 @@ static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
>  
>  static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
>  {
> +	enum resctrl_res_level i;
>  	struct resctrl_schema *s;
>  	struct rdt_resource *r;
>  	unsigned long fflags;
> @@ -2205,8 +2211,12 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
>  			goto out_destroy;
>  	}
>  
> -	for_each_mon_capable_rdt_resource(r) {
> -		fflags = r->fflags | RFTYPE_MON_INFO;
> +	for (i = 0; i < RDT_NUM_RESOURCES; i++) {
> +		r = resctrl_arch_get_resource(i);
> +		if (!r->mon_capable)
> +			continue;
> +
> +		fflags =  r->fflags | RFTYPE_MON_INFO;

Please check spacing.

>  		sprintf(name, "%s_MON", r->name);
>  		ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
>  		if (ret)
> @@ -2615,10 +2625,15 @@ static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type
>  
>  static int schemata_list_create(void)
>  {
> +	enum resctrl_res_level i;
>  	struct rdt_resource *r;
>  	int ret = 0;
>  
> -	for_each_alloc_capable_rdt_resource(r) {
> +	for (i = 0; i < RDT_NUM_RESOURCES; i++) {
> +		r = resctrl_arch_get_resource(i);
> +		if (!r->alloc_capable)
> +			continue;
> +
>  		if (resctrl_arch_get_cdp_enabled(r->rid)) {
>  			ret = schemata_list_add(r, CDP_CODE);
>  			if (ret)
> @@ -3166,6 +3181,7 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
>  			     struct rdtgroup *prgrp,
>  			     struct kernfs_node **dest_kn)
>  {
> +	enum resctrl_res_level i;
>  	struct rdt_resource *r;
>  	struct kernfs_node *kn;
>  	int ret;
> @@ -3184,7 +3200,11 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
>  	 * Create the subdirectories for each domain. Note that all events
>  	 * in a domain like L3 are grouped into a resource whose domain is L3
>  	 */
> -	for_each_mon_capable_rdt_resource(r) {
> +	for (i = 0; i < RDT_NUM_RESOURCES; i++) {
> +		r = resctrl_arch_get_resource(i);
> +		if (!r->mon_capable)
> +			continue;
> +
>  		ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
>  		if (ret)
>  			goto out_destroy;

Reinette