[PATCH] [RFC] sched/core: avoid checking in_atomic_preempt_off twice

[PATCH] [RFC] sched/core: avoid checking in_atomic_preempt_off twice

[liming.wu]

From: Liming Wu <liming.wu@jaguarmicro.com>

in_atomic_preempt_off is checked twice in schedule_debug, and
__schedule_bug only called in schedule_debug. remove the redundant
in_atomic_preempt_off check in __schedule_bug.

Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
---
 kernel/sched/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a68d1276bab0..ae44958b3851 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5884,8 +5884,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 	print_modules();
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
-	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
-	    && in_atomic_preempt_off()) {
+	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) {
 		pr_err("Preemption disabled at:");
 		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}
-- 
2.25.1

[tip: sched/core] sched/debug: Avoid checking in_atomic_preempt_off() twice in schedule_debug()

[tip-bot2 for Liming Wu]

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

Commit-ID:     dc461c48deda8a2d243fbaf49e276d555eb833d8
Gitweb:        https://git.kernel.org/tip/dc461c48deda8a2d243fbaf49e276d555eb833d8
Author:        Liming Wu <liming.wu@jaguarmicro.com>
AuthorDate:    Fri, 25 Aug 2023 10:35:00 +08:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 22 Sep 2023 11:50:49 +02:00

sched/debug: Avoid checking in_atomic_preempt_off() twice in schedule_debug()

in_atomic_preempt_off() already gets called in schedule_debug() once,
which is the only caller of __schedule_bug().

Skip the second call within __schedule_bug(), it should always be true
at this point.

[ mingo: Clarified the changelog. ]

Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230825023501.1848-1-liming.wu@jaguarmicro.com
---
 kernel/sched/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 52ceb85..1074934 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5899,8 +5899,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 	print_modules();
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
-	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
-	    && in_atomic_preempt_off()) {
+	if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) {
 		pr_err("Preemption disabled at:");
 		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}