[PATCH v10 17/20] timers: Introduce function to check timer base is_idle flag

Anna-Maria Behnsen posted 20 patches 1 year, 11 months ago
There is a newer version of this series
[PATCH v10 17/20] timers: Introduce function to check timer base is_idle flag
Posted by Anna-Maria Behnsen 1 year, 11 months ago
 flag

To prepare for the conversion of the NOHZ timer placement to a pull at
expiry time model it's required to have a function that returns the value
of the is_idle flag of the timer base to keep the hierarchy states during
online in sync with timer base state.

No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
---
v10: Fix fallout of 0day: Move function definition of timer_base_is_idle()
     into SMP && NO_HZ_COMMON ifdef section

v9: new in v9
---
 kernel/time/tick-internal.h |  1 +
 kernel/time/timer.c         | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index ccf39befde85..7e3090109e33 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -165,6 +165,7 @@ extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
 					      unsigned int cpu);
 extern void timer_lock_remote_bases(unsigned int cpu);
 extern void timer_unlock_remote_bases(unsigned int cpu);
+extern bool timer_base_is_idle(void);
 # endif
 #else /* CONFIG_NO_HZ_COMMON */
 static inline void timers_update_nohz(void) { }
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index eb99297a96fe..3c49d8fdfd53 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -2099,6 +2099,16 @@ void timer_lock_remote_bases(unsigned int cpu)
 	raw_spin_lock(&base_local->lock);
 	raw_spin_lock_nested(&base_global->lock, SINGLE_DEPTH_NESTING);
 }
+
+/**
+ * timer_base_is_idle() - Return whether timer base is set idle
+ *
+ * Returns value of local timer base is_idle value.
+ */
+bool timer_base_is_idle(void)
+{
+	return __this_cpu_read(timer_bases[BASE_LOCAL].is_idle);
+}
 # endif /* CONFIG_SMP */
 
 static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 basem,
-- 
2.39.2
Re: [PATCH v10 17/20] timers: Introduce function to check timer base is_idle flag
Posted by Frederic Weisbecker 1 year, 10 months ago
Le Mon, Jan 15, 2024 at 03:37:40PM +0100, Anna-Maria Behnsen a écrit :
>  flag
> 
> To prepare for the conversion of the NOHZ timer placement to a pull at
> expiry time model it's required to have a function that returns the value
> of the is_idle flag of the timer base to keep the hierarchy states during
> online in sync with timer base state.
> 
> No functional change.
> 
> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>