[PATCH v14 03/32] x86,fs/resctrl: Replace architecture event enabled checks

From: Babu Moger
Date: Fri Jun 13 2025 - 17:06:27 EST


From: Tony Luck <tony.luck@xxxxxxxxx>

The resctrl file system now has complete knowledge of the status
of every event. So there is no need for per-event function calls
to check.

Replace each of the resctrl_arch_is_{event}enabled() calls with
resctrl_is_mon_event_enabled(QOS_{EVENT}).

No functional change.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
v14: This is Tony's work. This is part of Tony's telemetry series.
https://lore.kernel.org/lkml/20250521225049.132551-1-tony.luck@xxxxxxxxx/

Tony made special update for me to include in this series.
https://lore.kernel.org/lkml/20250609162139.91651-1-tony.luck@xxxxxxxxx/
---
arch/x86/include/asm/resctrl.h | 15 ---------------
arch/x86/kernel/cpu/resctrl/core.c | 4 ++--
arch/x86/kernel/cpu/resctrl/monitor.c | 4 ++--
fs/resctrl/ctrlmondata.c | 4 ++--
fs/resctrl/monitor.c | 16 +++++++++++-----
fs/resctrl/rdtgroup.c | 18 +++++++++---------
include/linux/resctrl.h | 2 ++
7 files changed, 28 insertions(+), 35 deletions(-)

diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index feb93b50e990..b1dd5d6b87db 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -84,21 +84,6 @@ static inline void resctrl_arch_disable_mon(void)
static_branch_dec_cpuslocked(&rdt_enable_key);
}

-static inline bool resctrl_arch_is_llc_occupancy_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_OCCUP_EVENT_ID));
-}
-
-static inline bool resctrl_arch_is_mbm_total_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_MBM_TOTAL_EVENT_ID));
-}
-
-static inline bool resctrl_arch_is_mbm_local_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_MBM_LOCAL_EVENT_ID));
-}
-
/*
* __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
*
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 7fcae25874fe..1a319ce9328c 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -402,13 +402,13 @@ static int arch_domain_mbm_alloc(u32 num_rmid, struct rdt_hw_mon_domain *hw_dom)
{
size_t tsize;

- if (resctrl_arch_is_mbm_total_enabled()) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) {
tsize = sizeof(*hw_dom->arch_mbm_total);
hw_dom->arch_mbm_total = kcalloc(num_rmid, tsize, GFP_KERNEL);
if (!hw_dom->arch_mbm_total)
return -ENOMEM;
}
- if (resctrl_arch_is_mbm_local_enabled()) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) {
tsize = sizeof(*hw_dom->arch_mbm_local);
hw_dom->arch_mbm_local = kcalloc(num_rmid, tsize, GFP_KERNEL);
if (!hw_dom->arch_mbm_local) {
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index c261558276cd..61d38517e2bf 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -207,11 +207,11 @@ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *
{
struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);

- if (resctrl_arch_is_mbm_total_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))
memset(hw_dom->arch_mbm_total, 0,
sizeof(*hw_dom->arch_mbm_total) * r->num_rmid);

- if (resctrl_arch_is_mbm_local_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID))
memset(hw_dom->arch_mbm_local, 0,
sizeof(*hw_dom->arch_mbm_local) * r->num_rmid);
}
diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index d98e0d2de09f..ad7ffc6acf13 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -473,12 +473,12 @@ ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
rdt_last_cmd_clear();

if (!strcmp(buf, "mbm_local_bytes")) {
- if (resctrl_arch_is_mbm_local_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID))
rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID;
else
ret = -EINVAL;
} else if (!strcmp(buf, "mbm_total_bytes")) {
- if (resctrl_arch_is_mbm_total_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))
rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID;
else
ret = -EINVAL;
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 2313e48de55f..9e988b2c1a22 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -336,7 +336,7 @@ void free_rmid(u32 closid, u32 rmid)

entry = __rmid_entry(idx);

- if (resctrl_arch_is_llc_occupancy_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID))
add_rmid_to_limbo(entry);
else
list_add_tail(&entry->list, &rmid_free_lru);
@@ -637,10 +637,10 @@ static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
* This is protected from concurrent reads from user as both
* the user and overflow handler hold the global mutex.
*/
- if (resctrl_arch_is_mbm_total_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))
mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);

- if (resctrl_arch_is_mbm_local_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID))
mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
}

@@ -879,6 +879,12 @@ void resctrl_enable_mon_event(enum resctrl_event_id eventid)
mon_event_all[eventid].enabled = true;
}

+bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid)
+{
+ return eventid >= QOS_FIRST_EVENT && eventid < QOS_NUM_EVENTS &&
+ mon_event_all[eventid].enabled;
+}
+
/**
* resctrl_mon_resource_init() - Initialise global monitoring structures.
*
@@ -914,9 +920,9 @@ int resctrl_mon_resource_init(void)
RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
}

- if (resctrl_arch_is_mbm_local_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID))
mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID;
- else if (resctrl_arch_is_mbm_total_enabled())
+ else if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))
mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;

return 0;
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index b95501d4b5de..a7eeb33501da 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -123,8 +123,8 @@ void rdt_staged_configs_clear(void)

static bool resctrl_is_mbm_enabled(void)
{
- return (resctrl_arch_is_mbm_total_enabled() ||
- resctrl_arch_is_mbm_local_enabled());
+ return (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID) ||
+ resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID));
}

static bool resctrl_is_mbm_event(int e)
@@ -196,7 +196,7 @@ static int closid_alloc(void)
lockdep_assert_held(&rdtgroup_mutex);

if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) &&
- resctrl_arch_is_llc_occupancy_enabled()) {
+ resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID)) {
cleanest_closid = resctrl_find_cleanest_closid();
if (cleanest_closid < 0)
return cleanest_closid;
@@ -4051,7 +4051,7 @@ void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d

if (resctrl_is_mbm_enabled())
cancel_delayed_work(&d->mbm_over);
- if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID) && has_busy_rmid(d)) {
/*
* When a package is going down, forcefully
* decrement rmid->ebusy. There is no way to know
@@ -4087,12 +4087,12 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
size_t tsize;

- if (resctrl_arch_is_llc_occupancy_enabled()) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID)) {
d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL);
if (!d->rmid_busy_llc)
return -ENOMEM;
}
- if (resctrl_arch_is_mbm_total_enabled()) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) {
tsize = sizeof(*d->mbm_total);
d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL);
if (!d->mbm_total) {
@@ -4100,7 +4100,7 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain
return -ENOMEM;
}
}
- if (resctrl_arch_is_mbm_local_enabled()) {
+ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) {
tsize = sizeof(*d->mbm_local);
d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL);
if (!d->mbm_local) {
@@ -4145,7 +4145,7 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
RESCTRL_PICK_ANY_CPU);
}

- if (resctrl_arch_is_llc_occupancy_enabled())
+ if (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID))
INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);

/*
@@ -4220,7 +4220,7 @@ void resctrl_offline_cpu(unsigned int cpu)
cancel_delayed_work(&d->mbm_over);
mbm_setup_overflow_handler(d, 0, cpu);
}
- if (resctrl_arch_is_llc_occupancy_enabled() &&
+ if (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID) &&
cpu == d->cqm_work_cpu && has_busy_rmid(d)) {
cancel_delayed_work(&d->cqm_limbo);
cqm_setup_limbo_handler(d, 0, cpu);
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 2944042bd84c..40aba6b5d4f0 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -372,6 +372,8 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);

void resctrl_enable_mon_event(enum resctrl_event_id eventid);

+bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid);
+
bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);

/**
--
2.34.1