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

Reinette Chatre
2024-04-09T03:19:49Z

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