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-rw-r--r--drivers/resctrl/mpam_resctrl.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 9a15ddd340f7..f82fff3519df 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -438,6 +438,42 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr,
closid, rmid, val);
}
+/*
+ * The rmid realloc threshold should be for the smallest cache exposed to
+ * resctrl.
+ */
+static int update_rmid_limits(struct mpam_class *class)
+{
+ u32 num_unique_pmg = resctrl_arch_system_num_rmid_idx();
+ struct mpam_props *cprops = &class->props;
+ struct cacheinfo *ci;
+
+ lockdep_assert_cpus_held();
+
+ if (!mpam_has_feature(mpam_feat_msmon_csu, cprops))
+ return 0;
+
+ /*
+ * Assume cache levels are the same size for all CPUs...
+ * The check just requires any online CPU and it can't go offline as we
+ * hold the cpu lock.
+ */
+ ci = get_cpu_cacheinfo_level(raw_smp_processor_id(), class->level);
+ if (!ci || ci->size == 0) {
+ pr_debug("Could not read cache size for class %u\n",
+ class->level);
+ return -EINVAL;
+ }
+
+ if (!resctrl_rmid_realloc_limit ||
+ ci->size < resctrl_rmid_realloc_limit) {
+ resctrl_rmid_realloc_limit = ci->size;
+ resctrl_rmid_realloc_threshold = ci->size / num_unique_pmg;
+ }
+
+ return 0;
+}
+
static bool cache_has_usable_cpor(struct mpam_class *class)
{
struct mpam_props *cprops = &class->props;
@@ -850,6 +886,9 @@ static void mpam_resctrl_pick_counters(void)
/* CSU counters only make sense on a cache. */
switch (class->type) {
case MPAM_CLASS_CACHE:
+ if (update_rmid_limits(class))
+ break;
+
counter_update_class(QOS_L3_OCCUP_EVENT_ID, class);
break;
default: