sched/uclamp: Use the uclamp_is_used() helper instead of open-coding it

JIRA: https://issues.redhat.com/browse/RHEL-110301

commit 5fca5a4
Author: Xuewen Yan <[email protected]>
Date:   Wed Feb 19 17:37:46 2025 +0800

    sched/uclamp: Use the uclamp_is_used() helper instead of open-coding it

    Don't open-code static_branch_unlikely(&sched_uclamp_used), we have
    the uclamp_is_used() wrapper around it.

    [ mingo: Clean up the changelog ]

    Signed-off-by: Xuewen Yan <[email protected]>
    Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
    Signed-off-by: Ingo Molnar <[email protected]>
    Reviewed-by: Hongyan Xia <[email protected]>
    Reviewed-by: Christian Loehle <[email protected]>
    Reviewed-by: Vincent Guittot <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]

Signed-off-by: Phil Auld <[email protected]>

Author: auldp

kernel/sched/core.c

@@ -1732,7 +1732,7 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p, int flags
 	 * The condition is constructed such that a NOP is generated when
 	 * sched_uclamp_used is disabled.
 	 */
-	if (!static_branch_unlikely(&sched_uclamp_used))
+	if (!uclamp_is_used())
 		return;
 
 	if (unlikely(!p->sched_class->uclamp_enabled))
@@ -1760,7 +1760,7 @@ static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p)
 	 * The condition is constructed such that a NOP is generated when
 	 * sched_uclamp_used is disabled.
 	 */
-	if (!static_branch_unlikely(&sched_uclamp_used))
+	if (!uclamp_is_used())
 		return;
 
 	if (unlikely(!p->sched_class->uclamp_enabled))

kernel/sched/sched.h

@@ -3240,6 +3240,19 @@ static inline unsigned long cpu_util_rt(struct rq *rq)
 
 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
 
+/*
+ * When uclamp is compiled in, the aggregation at rq level is 'turned off'
+ * by default in the fast path and only gets turned on once userspace performs
+ * an operation that requires it.
+ *
+ * Returns true if userspace opted-in to use uclamp and aggregation at rq level
+ * hence is active.
+ */
+static inline bool uclamp_is_used(void)
+{
+	return static_branch_likely(&sched_uclamp_used);
+}
+
 static inline unsigned long uclamp_rq_get(struct rq *rq,
 					  enum uclamp_id clamp_id)
 {
@@ -3263,7 +3276,7 @@ static inline bool uclamp_rq_is_capped(struct rq *rq)
 	unsigned long rq_util;
 	unsigned long max_util;
 
-	if (!static_branch_likely(&sched_uclamp_used))
+	if (!uclamp_is_used())
 		return false;
 
 	rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq);
@@ -3272,19 +3285,6 @@ static inline bool uclamp_rq_is_capped(struct rq *rq)
 	return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util;
 }
 
-/*
- * When uclamp is compiled in, the aggregation at rq level is 'turned off'
- * by default in the fast path and only gets turned on once userspace performs
- * an operation that requires it.
- *
- * Returns true if userspace opted-in to use uclamp and aggregation at rq level
- * hence is active.
- */
-static inline bool uclamp_is_used(void)
-{
-	return static_branch_likely(&sched_uclamp_used);
-}
-
 #define for_each_clamp_id(clamp_id) \
 	for ((clamp_id) = 0; (clamp_id) < UCLAMP_CNT; (clamp_id)++)