sched/smp: Make SMP unconditional

Simplify the scheduler by making CONFIG_SMP=y primitives and data
structures unconditional.

Introduce transitory wrappers for functionality not yet converted to SMP.

Note that this patch is pretty large, because there's no clear separation
between various aspects of the SMP scheduler, it's basically a huge block
of #ifdef CONFIG_SMP. A fair amount of it has to be switched on for it to
boot and work on UP systems.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250528080924.2273858-21-mingo@kernel.org

1 files changed, 0 insertions, 52 deletions

diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
index a5d4933e6b70..62c3fa543c0f 100644
--- a/kernel/sched/pelt.h
+++ b/kernel/sched/pelt.h
@@ -3,7 +3,6 @@
 #define _KERNEL_SCHED_PELT_H
 #include "sched.h"
 
-#ifdef CONFIG_SMP
 #include "sched-pelt.h"
 
 int __update_load_avg_blocked_se(u64 now, struct sched_entity *se);
@@ -187,55 +186,4 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
 }
 #endif /* !CONFIG_CFS_BANDWIDTH */
 
-#else /* !CONFIG_SMP: */
-
-static inline int
-update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
-{
-	return 0;
-}
-
-static inline int
-update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
-{
-	return 0;
-}
-
-static inline int
-update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
-{
-	return 0;
-}
-
-static inline int
-update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
-{
-	return 0;
-}
-
-static inline u64 hw_load_avg(struct rq *rq)
-{
-	return 0;
-}
-
-static inline int
-update_irq_load_avg(struct rq *rq, u64 running)
-{
-	return 0;
-}
-
-static inline u64 rq_clock_pelt(struct rq *rq)
-{
-	return rq_clock_task(rq);
-}
-
-static inline void
-update_rq_clock_pelt(struct rq *rq, s64 delta) { }
-
-static inline void
-update_idle_rq_clock_pelt(struct rq *rq) { }
-
-static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) { }
-#endif /* !CONFIG_SMP */
-
 #endif /* _KERNEL_SCHED_PELT_H */