iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

timers: Restructure internal locking

Browse Source 
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@gmail.com>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240221090548.36600-15-anna-maria@linutronix.de
This commit is contained in:
Richard Cochran (linutronix GmbH) 2024-02-21 10:05:42 +01:00 committed by Thomas Gleixner
parent f73d9257ff
commit 90f5df66c8
1 changed files with 21 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
kernel/time/timer.c
View File

@ -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);
}
}