[tip: sched/core] sched: dynamic: Simplify preempt_schedule{,_notrace}()

[tip-bot2 for Mark Rutland]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     b9d267b9d632feec9ddd1ce12078b7113f429a51
Gitweb:        https://git.kernel.org/tip/b9d267b9d632feec9ddd1ce12078b7113f429a51
Author:        Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate:    Mon, 03 Aug 2026 20:17:28 +01:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 02 Sep 2026 09:37:22 +02:00

sched: dynamic: Simplify preempt_schedule{,_notrace}()

PREEMPT_DYNAMIC is now limited to the FULL and LAZY preemption models.
In either model, both preempt_schedule() and preempt_schedule_notrace()
are always called and never disabled.

Remove the unnecessary code for these when PREEMPT_DYNAMIC is selected.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Reviewed-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Tested-by: Mete Durlu <meted@xxxxxxxxxxxxx>
Tested-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Tested-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Link: https://patch.msgid.link/20260803191731.3244294-4-mark.rutland@xxxxxxx
---
 arch/arm64/include/asm/preempt.h | 10 +------
 arch/s390/include/asm/preempt.h  | 11 +-------
 arch/x86/include/asm/preempt.h   | 28 +-----------------
 include/asm-generic/preempt.h    | 10 +------
 kernel/sched/core.c              | 52 +-------------------------------
 5 files changed, 111 deletions(-)

diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 9ecc276..e86e850 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -104,19 +104,9 @@ static inline bool should_resched(int preempt_offset)
 void preempt_schedule(void);
 void preempt_schedule_notrace(void);
 
-#ifdef CONFIG_PREEMPT_DYNAMIC
-
-void dynamic_preempt_schedule(void);
-#define __preempt_schedule()		dynamic_preempt_schedule()
-void dynamic_preempt_schedule_notrace(void);
-#define __preempt_schedule_notrace()	dynamic_preempt_schedule_notrace()
-
-#else /* CONFIG_PREEMPT_DYNAMIC */
-
 #define __preempt_schedule()		preempt_schedule()
 #define __preempt_schedule_notrace()	preempt_schedule_notrace()
 
-#endif /* CONFIG_PREEMPT_DYNAMIC */
 #endif /* CONFIG_PREEMPTION */
 
 #endif /* __ASM_PREEMPT_H */
diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h
index 5560d5f..60c6f01 100644
--- a/arch/s390/include/asm/preempt.h
+++ b/arch/s390/include/asm/preempt.h
@@ -155,20 +155,9 @@ static __always_inline int __preempt_count_sub_return(int val)
 void preempt_schedule(void);
 void preempt_schedule_notrace(void);
 
-#ifdef CONFIG_PREEMPT_DYNAMIC
-
-void dynamic_preempt_schedule(void);
-void dynamic_preempt_schedule_notrace(void);
-#define __preempt_schedule()		dynamic_preempt_schedule()
-#define __preempt_schedule_notrace()	dynamic_preempt_schedule_notrace()
-
-#else /* CONFIG_PREEMPT_DYNAMIC */
-
 #define __preempt_schedule()		preempt_schedule()
 #define __preempt_schedule_notrace()	preempt_schedule_notrace()
 
-#endif /* CONFIG_PREEMPT_DYNAMIC */
-
 #endif /* CONFIG_PREEMPTION */
 
 #endif /* __ASM_PREEMPT_H */
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index fafb6f8..d16d9c2 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -137,43 +137,15 @@ static __always_inline bool should_resched(int preempt_offset)
 extern asmlinkage void preempt_schedule(void);
 extern asmlinkage void preempt_schedule_thunk(void);
 
-#define preempt_schedule_dynamic_enabled	preempt_schedule_thunk
-#define preempt_schedule_dynamic_disabled	NULL
-
 extern asmlinkage void preempt_schedule_notrace(void);
 extern asmlinkage void preempt_schedule_notrace_thunk(void);
 
-#define preempt_schedule_notrace_dynamic_enabled	preempt_schedule_notrace_thunk
-#define preempt_schedule_notrace_dynamic_disabled	NULL
-
-#ifdef CONFIG_PREEMPT_DYNAMIC
-
-DECLARE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled);
-
-#define __preempt_schedule() \
-do { \
-	__STATIC_CALL_MOD_ADDRESSABLE(preempt_schedule); \
-	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \
-} while (0)
-
-DECLARE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled);
-
-#define __preempt_schedule_notrace() \
-do { \
-	__STATIC_CALL_MOD_ADDRESSABLE(preempt_schedule_notrace); \
-	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule_notrace) : ASM_CALL_CONSTRAINT); \
-} while (0)
-
-#else /* PREEMPT_DYNAMIC */
-
 #define __preempt_schedule() \
 	asm volatile ("call preempt_schedule_thunk" : ASM_CALL_CONSTRAINT);
 
 #define __preempt_schedule_notrace() \
 	asm volatile ("call preempt_schedule_notrace_thunk" : ASM_CALL_CONSTRAINT);
 
-#endif /* PREEMPT_DYNAMIC */
-
 #endif /* PREEMPTION */
 
 #undef __pc_op
diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h
index c8683c0..1adddea 100644
--- a/include/asm-generic/preempt.h
+++ b/include/asm-generic/preempt.h
@@ -96,19 +96,9 @@ static __always_inline bool should_resched(int preempt_offset)
 extern asmlinkage void preempt_schedule(void);
 extern asmlinkage void preempt_schedule_notrace(void);
 
-#if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
-
-void dynamic_preempt_schedule(void);
-void dynamic_preempt_schedule_notrace(void);
-#define __preempt_schedule()		dynamic_preempt_schedule()
-#define __preempt_schedule_notrace()	dynamic_preempt_schedule_notrace()
-
-#else /* !CONFIG_PREEMPT_DYNAMIC || !CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
-
 #define __preempt_schedule() preempt_schedule()
 #define __preempt_schedule_notrace() preempt_schedule_notrace()
 
-#endif /* CONFIG_PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
 #endif /* CONFIG_PREEMPTION */
 
 #endif /* __ASM_PREEMPT_H */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0060efc..844f374 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7500,27 +7500,6 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
 NOKPROBE_SYMBOL(preempt_schedule);
 EXPORT_SYMBOL(preempt_schedule);
 
-#ifdef CONFIG_PREEMPT_DYNAMIC
-# ifdef CONFIG_HAVE_PREEMPT_DYNAMIC_CALL
-#  ifndef preempt_schedule_dynamic_enabled
-#   define preempt_schedule_dynamic_enabled	preempt_schedule
-#   define preempt_schedule_dynamic_disabled	NULL
-#  endif
-DEFINE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled);
-EXPORT_STATIC_CALL_TRAMP(preempt_schedule);
-# elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
-static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule);
-void __sched notrace dynamic_preempt_schedule(void)
-{
-	if (!static_branch_unlikely(&sk_dynamic_preempt_schedule))
-		return;
-	preempt_schedule();
-}
-NOKPROBE_SYMBOL(dynamic_preempt_schedule);
-EXPORT_SYMBOL(dynamic_preempt_schedule);
-# endif
-#endif /* CONFIG_PREEMPT_DYNAMIC */
-
 /**
  * preempt_schedule_notrace - preempt_schedule called by tracing
  *
@@ -7573,27 +7552,6 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
 }
 EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
 
-#ifdef CONFIG_PREEMPT_DYNAMIC
-# if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
-#  ifndef preempt_schedule_notrace_dynamic_enabled
-#   define preempt_schedule_notrace_dynamic_enabled	preempt_schedule_notrace
-#   define preempt_schedule_notrace_dynamic_disabled	NULL
-#  endif
-DEFINE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled);
-EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace);
-# elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
-static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule_notrace);
-void __sched notrace dynamic_preempt_schedule_notrace(void)
-{
-	if (!static_branch_unlikely(&sk_dynamic_preempt_schedule_notrace))
-		return;
-	preempt_schedule_notrace();
-}
-NOKPROBE_SYMBOL(dynamic_preempt_schedule_notrace);
-EXPORT_SYMBOL(dynamic_preempt_schedule_notrace);
-# endif
-#endif
-
 #endif /* CONFIG_PREEMPTION */
 
 /*
@@ -7891,8 +7849,6 @@ EXPORT_SYMBOL(__cond_resched_rwlock_write);
 # endif
 
 /*
- * SC:preempt_schedule
- * SC:preempt_schedule_notrace
  * SC:irqentry_exit_cond_resched
  *
  *
@@ -7903,14 +7859,10 @@ EXPORT_SYMBOL(__cond_resched_rwlock_write);
  *   (unselectable)
  *
  * FULL:
- *   preempt_schedule           <- preempt_schedule
- *   preempt_schedule_notrace   <- preempt_schedule_notrace
  *   irqentry_exit_cond_resched <- irqentry_exit_cond_resched
  *   dynamic_preempt_lazy       <- false
  *
  * LAZY:
- *   preempt_schedule           <- preempt_schedule
- *   preempt_schedule_notrace   <- preempt_schedule_notrace
  *   irqentry_exit_cond_resched <- irqentry_exit_cond_resched
  *   dynamic_preempt_lazy       <- true
  */
@@ -7955,8 +7907,6 @@ static void __sched_dynamic_update(int mode)
 {
 	switch (mode) {
 	case preempt_dynamic_full:
-		preempt_dynamic_enable(preempt_schedule);
-		preempt_dynamic_enable(preempt_schedule_notrace);
 		preempt_dynamic_enable(irqentry_exit_cond_resched);
 		preempt_dynamic_key_disable(preempt_lazy);
 		if (mode != preempt_dynamic_mode)
@@ -7964,8 +7914,6 @@ static void __sched_dynamic_update(int mode)
 		break;
 
 	case preempt_dynamic_lazy:
-		preempt_dynamic_enable(preempt_schedule);
-		preempt_dynamic_enable(preempt_schedule_notrace);
 		preempt_dynamic_enable(irqentry_exit_cond_resched);
 		preempt_dynamic_key_enable(preempt_lazy);
 		if (mode != preempt_dynamic_mode)