The following commit has been merged into the timers/core branch of tip:
Commit-ID: 90f5df66c86c259d61aff84e16f519fe1424e1ef
Gitweb: https://git.kernel.org/tip/90f5df66c86c259d61aff84e16f519fe1424e1ef
Author: Richard Cochran (linutronix GmbH) <richardcochran@xxxxxxxxx>
AuthorDate: Wed, 21 Feb 2024 10:05:42 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Thu, 22 Feb 2024 17:52:31 +01:00
timers: Restructure internal locking
Move the locking out from __run_timers() to the call sites, so the
protected section can be extended at the call site. Preparatory work for
changing the NOHZ timer placement to a pull at expiry time model.
No functional change.
Signed-off-by: Richard Cochran (linutronix GmbH) <richardcochran@xxxxxxxxx>
Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240221090548.36600-15-anna-maria@xxxxxxxxxxxxx
---
kernel/time/timer.c | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index bc074c0..51053af 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -2283,11 +2283,7 @@ static inline void __run_timers(struct timer_base *base)
struct hlist_head heads[LVL_DEPTH];
int levels;
- if (time_before(jiffies, base->next_expiry))
- return;
-
- timer_base_lock_expiry(base);
- raw_spin_lock_irq(&base->lock);
+ lockdep_assert_held(&base->lock);
while (time_after_eq(jiffies, base->clk) &&
time_after_eq(jiffies, base->next_expiry)) {
@@ -2311,21 +2307,36 @@ static inline void __run_timers(struct timer_base *base)
while (levels--)
expire_timers(base, heads + levels);
}
+}
+
+static void __run_timer_base(struct timer_base *base)
+{
+ if (time_before(jiffies, base->next_expiry))
+ return;
+
+ timer_base_lock_expiry(base);
+ raw_spin_lock_irq(&base->lock);
+ __run_timers(base);
raw_spin_unlock_irq(&base->lock);
timer_base_unlock_expiry(base);
}
+static void run_timer_base(int index)
+{
+ struct timer_base *base = this_cpu_ptr(&timer_bases[index]);
+
+ __run_timer_base(base);
+}
+
/*
* This function runs timers and the timer-tq in bottom half context.
*/
static __latent_entropy void run_timer_softirq(struct softirq_action *h)
{
- struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_LOCAL]);
-
- __run_timers(base);
+ run_timer_base(BASE_LOCAL);
if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) {
- __run_timers(this_cpu_ptr(&timer_bases[BASE_GLOBAL]));
- __run_timers(this_cpu_ptr(&timer_bases[BASE_DEF]));
+ run_timer_base(BASE_GLOBAL);
+ run_timer_base(BASE_DEF);
}
}
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