sched/smp: Use the SMP version of the scheduler syscalls

Simplify the scheduler by making CONFIG_SMP=y code in
idle_cpu(), __sched_setscheduler() and sched_setaffinity()
unconditional.

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/20250528080924.2273858-33-mingo@kernel.org

diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c
index d7fccf871c7d5e73a22173b76b29e3b78389abd5..77ae87f36e841296c13266910c34a1d9a79659de 100644 (file)
--- a/kernel/sched/syscalls.c
+++ b/kernel/sched/syscalls.c
@@ -209,10 +209,8 @@ int idle_cpu(int cpu)
        if (rq->nr_running)
                return 0;
 
-#ifdef CONFIG_SMP
        if (rq->ttwu_pending)
                return 0;
-#endif
 
        return 1;
 }
@@ -641,7 +639,6 @@ change:
                        goto unlock;
                }
 #endif /* CONFIG_RT_GROUP_SCHED */
-#ifdef CONFIG_SMP
                if (dl_bandwidth_enabled() && dl_policy(policy) &&
                                !(attr->sched_flags & SCHED_FLAG_SUGOV)) {
                        cpumask_t *span = rq->rd->span;
@@ -657,7 +654,6 @@ change:
                                goto unlock;
                        }
                }
-#endif /* CONFIG_SMP */
        }
 
        /* Re-check policy now with rq lock held: */
@@ -1239,7 +1235,7 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
        user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE);
        if (user_mask) {
                cpumask_copy(user_mask, in_mask);
-       } else if (IS_ENABLED(CONFIG_SMP)) {
+       } else {
                return -ENOMEM;
        }