From 06ddd17521bf11a3e7f59dafdf5c148f29467d2c Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Wed, 28 May 2025 10:09:02 +0200
Subject: [PATCH] sched/smp: Always define is_percpu_thread() and
 scheduler_ipi()

Simplify the scheduler by making the CONFIG_SMP=y primitives
of is_percpu_thread() and scheduler_ipi() 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/20250528080924.2273858-22-mingo@kernel.org
---
 include/linux/sched.h | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 376befdec4b0d..eec6b225e9d14 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1765,12 +1765,8 @@ extern struct pid *cad_pid;
 
 static __always_inline bool is_percpu_thread(void)
 {
-#ifdef CONFIG_SMP
 	return (current->flags & PF_NO_SETAFFINITY) &&
 		(current->nr_cpus_allowed  == 1);
-#else
-	return true;
-#endif
 }
 
 /* Per-process atomic flags. */
@@ -1967,7 +1963,6 @@ extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec
 	buf;						\
 })
 
-#ifdef CONFIG_SMP
 static __always_inline void scheduler_ipi(void)
 {
 	/*
@@ -1977,9 +1972,6 @@ static __always_inline void scheduler_ipi(void)
 	 */
 	preempt_fold_need_resched();
 }
-#else
-static inline void scheduler_ipi(void) { }
-#endif
 
 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
 
-- 
2.47.2