[GIT PULL] scheduler fix

From: Ingo Molnar
Date: Fri Mar 14 2025 - 05:11:44 EST


Linus,

Please pull the latest sched/urgent Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-2025-03-14

# HEAD: f3fa0e40df175acd60b71036b9a1fd62310aec03 sched/clock: Don't define sched_clock_irqtime as static key

Fix a sleeping-while-atomic bug caused by a recent optimization
utilizing static keys that didn't consider that the
static_key_disable() call could be triggered in atomic context.

Revert the optimization.

Thanks,

Ingo

------------------>
Yafang Shao (1):
sched/clock: Don't define sched_clock_irqtime as static key


kernel/sched/cputime.c | 8 ++++----
kernel/sched/sched.h | 4 ++--
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 5d9143dd0879..6dab4854c6c0 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -9,8 +9,6 @@

#ifdef CONFIG_IRQ_TIME_ACCOUNTING

-DEFINE_STATIC_KEY_FALSE(sched_clock_irqtime);
-
/*
* There are no locks covering percpu hardirq/softirq time.
* They are only modified in vtime_account, on corresponding CPU
@@ -24,14 +22,16 @@ DEFINE_STATIC_KEY_FALSE(sched_clock_irqtime);
*/
DEFINE_PER_CPU(struct irqtime, cpu_irqtime);

+int sched_clock_irqtime;
+
void enable_sched_clock_irqtime(void)
{
- static_branch_enable(&sched_clock_irqtime);
+ sched_clock_irqtime = 1;
}

void disable_sched_clock_irqtime(void)
{
- static_branch_disable(&sched_clock_irqtime);
+ sched_clock_irqtime = 0;
}

static void irqtime_account_delta(struct irqtime *irqtime, u64 delta,
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c8512a9fb022..023b844159c9 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3259,11 +3259,11 @@ struct irqtime {
};

DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
-DECLARE_STATIC_KEY_FALSE(sched_clock_irqtime);
+extern int sched_clock_irqtime;

static inline int irqtime_enabled(void)
{
- return static_branch_likely(&sched_clock_irqtime);
+ return sched_clock_irqtime;
}

/*