diff mbox series

[v10,16/20] tick/sched: Split out jiffies update helper function

Message ID 20240115143743.27827-17-anna-maria@linutronix.de
State New
Headers
Series timers: Move from a push remote at enqueue to a pull at expiry model |

Commit Message

Anna-Maria Behnsen Jan. 15, 2024, 2:37 p.m. UTC 
  From: "Richard Cochran (linutronix GmbH)" <richardcochran@gmail.com>

The logic to get the time of the last jiffies update will be needed by
the timer pull model as well.

Move the code into a global function in anticipation of the new caller.

No functional change.

Signed-off-by: Richard Cochran (linutronix GmbH) <richardcochran@gmail.com>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
---
 kernel/time/tick-internal.h |  1 +
 kernel/time/tick-sched.c    | 18 +++++++++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

Comments

Frederic Weisbecker Jan. 24, 2024, 2:42 p.m. UTC | #1 
Le Mon, Jan 15, 2024 at 03:37:39PM +0100, Anna-Maria Behnsen a écrit :
> From: "Richard Cochran (linutronix GmbH)" <richardcochran@gmail.com>
> 
> The logic to get the time of the last jiffies update will be needed by
> the timer pull model as well.
> 
> Move the code into a global function in anticipation of the new caller.
> 
> No functional change.
> 
> Signed-off-by: Richard Cochran (linutronix GmbH) <richardcochran@gmail.com>
> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>

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

Patch

diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 8b0c28edbd09..ccf39befde85 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -157,6 +157,7 @@  static inline void tick_nohz_init(void) { }
 #ifdef CONFIG_NO_HZ_COMMON
 extern unsigned long tick_nohz_active;
 extern void timers_update_nohz(void);
+extern u64 get_jiffies_update(unsigned long *basej);
 # ifdef CONFIG_SMP
 extern struct static_key_false timers_migration_enabled;
 extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 27f1a2ae7f39..a3eb5165d439 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -799,18 +799,30 @@  static inline bool local_timer_softirq_pending(void)
 	return local_softirq_pending() & BIT(TIMER_SOFTIRQ);
 }
 
-static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
+/*
+ * Read jiffies and the time when jiffies were updated last
+ */
+u64 get_jiffies_update(unsigned long *basej)
 {
-	u64 basemono, next_tick, delta, expires;
 	unsigned long basejiff;
 	unsigned int seq;
+	u64 basemono;
 
-	/* Read jiffies and the time when jiffies were updated last */
 	do {
 		seq = read_seqcount_begin(&jiffies_seq);
 		basemono = last_jiffies_update;
 		basejiff = jiffies;
 	} while (read_seqcount_retry(&jiffies_seq, seq));
+	*basej = basejiff;
+	return basemono;
+}
+
+static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
+{
+	u64 basemono, next_tick, delta, expires;
+	unsigned long basejiff;
+
+	basemono = get_jiffies_update(&basejiff);
 	ts->last_jiffies = basejiff;
 	ts->timer_expires_base = basemono;