[PATCH v10 08/13] x86/resctrl: Support monitor configuration

From: Babu Moger
Date: Thu Dec 22 2022 - 18:32:45 EST


Add a new field in struct mon_evt to support Bandwidth Monitoring Event
Configuration(BMEC) and also update the "mon_features" display.

The resctrl file "mon_features" will display the supported events
and files that can be used to configure those events if monitor
configuration is supported.

Before the change.
$cat /sys/fs/resctrl/info/L3_MON/mon_features
llc_occupancy
mbm_total_bytes
mbm_local_bytes

After the change when BMEC is supported.
$cat /sys/fs/resctrl/info/L3_MON/mon_features
llc_occupancy
mbm_total_bytes
mbm_total_bytes_config
mbm_local_bytes
mbm_local_bytes_config

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
arch/x86/kernel/cpu/resctrl/internal.h | 2 ++
arch/x86/kernel/cpu/resctrl/monitor.c | 7 +++++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 5 ++++-
3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index f16b8bc5448c..0605b04f1b7a 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -52,11 +52,13 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
* struct mon_evt - Entry in the event list of a resource
* @evtid: event id
* @name: name of the event
+ * @configurable: true if the event is configurable
* @list: entry in &rdt_resource->evt_list
*/
struct mon_evt {
enum resctrl_event_id evtid;
char *name;
+ bool configurable;
struct list_head list;
};

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index e33e8d8bd796..b39e0eca1879 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -783,6 +783,13 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
if (ret)
return ret;

+ if (rdt_cpu_has(X86_FEATURE_BMEC)) {
+ if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL))
+ mbm_total_event.configurable = true;
+ if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL))
+ mbm_local_event.configurable = true;
+ }
+
l3_mon_evt_init(r);

r->mon_capable = true;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index aa469d708991..f34c70c7a791 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -996,8 +996,11 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
struct rdt_resource *r = of->kn->parent->priv;
struct mon_evt *mevt;

- list_for_each_entry(mevt, &r->evt_list, list)
+ list_for_each_entry(mevt, &r->evt_list, list) {
seq_printf(seq, "%s\n", mevt->name);
+ if (mevt->configurable)
+ seq_printf(seq, "%s_config\n", mevt->name);
+ }

return 0;
}
--
2.34.1