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

Commit-ID:     9650ce11f2e377310332d87a902dc4df3f59b905
Gitweb:        https://git.kernel.org/tip/9650ce11f2e377310332d87a902dc4df3f59b905
Author:        Mark Rutland <mark.rutland@arm.com>
AuthorDate:    Mon, 03 Aug 2026 20:17:31 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Sep 2026 09:37:24 +02:00

sched: dynamic: Simplify preempt model accessors

PREEMPT_DYNAMIC is now limited to the FULL and LAZY preemption models.
When CONFIG_PREEMPT_DYNAMIC=y, the NONE and VOLUNTARY models cannot be
used, and neither CONFIG_PREEMPT_NONE nor CONFIG_PREEMPT_VOLUNTARY can
be selected.

Simplify the preempt model accessors accordingly: remove the out-of-line
implementations of preempt_model_none() and preempt_model_voluntary(),
and remove the preempt_dynamic_{none,voluntary} values.

There are no current users of preempt_model_voluntary(), but I've kept
it around for consistency, with every scheduler model having its own
preempt_model_*() accessor.

Suggested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Mete Durlu <meted@linux.ibm.com>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260803191731.3244294-7-mark.rutland@arm.com
---
 include/linux/preempt.h | 20 ++++++++++----------
 kernel/sched/core.c     |  4 ----
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 8299657..4031067 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -502,21 +502,11 @@ DEFINE_LOCK_GUARD_0(preempt_notrace, preempt_disable_notrace(), preempt_enable_n
 
 #ifdef CONFIG_PREEMPT_DYNAMIC
 
-extern bool preempt_model_none(void);
-extern bool preempt_model_voluntary(void);
 extern bool preempt_model_full(void);
 extern bool preempt_model_lazy(void);
 
 #else
 
-static inline bool preempt_model_none(void)
-{
-	return IS_ENABLED(CONFIG_PREEMPT_NONE);
-}
-static inline bool preempt_model_voluntary(void)
-{
-	return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
-}
 static inline bool preempt_model_full(void)
 {
 	return IS_ENABLED(CONFIG_PREEMPT);
@@ -529,6 +519,16 @@ static inline bool preempt_model_lazy(void)
 
 #endif
 
+static inline bool preempt_model_none(void)
+{
+	return IS_ENABLED(CONFIG_PREEMPT_NONE);
+}
+
+static inline bool preempt_model_voluntary(void)
+{
+	return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
+}
+
 static inline bool preempt_model_rt(void)
 {
 	return IS_ENABLED(CONFIG_PREEMPT_RT);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0592320..c9dd6f4 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7864,8 +7864,6 @@ EXPORT_SYMBOL(__cond_resched_rwlock_write);
 
 enum {
 	preempt_dynamic_undefined = -1,
-	preempt_dynamic_none,
-	preempt_dynamic_voluntary,
 	preempt_dynamic_full,
 	preempt_dynamic_lazy,
 };
@@ -7950,8 +7948,6 @@ static void __init preempt_dynamic_init(void)
 	}								\
 	EXPORT_SYMBOL_GPL(preempt_model_##mode)
 
-PREEMPT_MODEL_ACCESSOR(none);
-PREEMPT_MODEL_ACCESSOR(voluntary);
 PREEMPT_MODEL_ACCESSOR(full);
 PREEMPT_MODEL_ACCESSOR(lazy);