linux-kernel - [PATCH v8 14/25] timers: Ease code in run_local

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Message-Id: <20231004123454.15691-15-anna-maria@linutronix.de>
Date:   Wed,  4 Oct 2023 14:34:43 +0200
From:   Anna-Maria Behnsen <anna-maria@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        John Stultz <jstultz@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Eric Dumazet <edumazet@...gle.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Arjan van de Ven <arjan@...radead.org>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Frederic Weisbecker <frederic@...nel.org>,
        Rik van Riel <riel@...riel.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Sebastian Siewior <bigeasy@...utronix.de>,
        Giovanni Gherdovich <ggherdovich@...e.cz>,
        Lukasz Luba <lukasz.luba@....com>,
        "Gautham R . Shenoy" <gautham.shenoy@....com>,
        Srinivas Pandruvada <srinivas.pandruvada@...el.com>,
        K Prateek Nayak <kprateek.nayak@....com>,
        Anna-Maria Behnsen <anna-maria@...utronix.de>
Subject: [PATCH v8 14/25] timers: Ease code in run_local_timers()

The logic for raising a softirq the way it is implemented right now, is
readable for two timer bases. When increasing numbers of timer bases, code
gets harder to read. With the introduction of the timer migration
hierarchy, there will be three timer bases.

Therefore ease the code. No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@...utronix.de>
Reviewed-by: Frederic Weisbecker <frederic@...nel.org>
---
v5: New patch to decrease patch size of follow up patches
---
 kernel/time/timer.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 853a8ee48ffc..1aafa0edc74c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -2123,16 +2123,14 @@ static void run_local_timers(void)
 	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 
 	hrtimer_run_queues();
-	/* Raise the softirq only if required. */
-	if (time_before(jiffies, base->next_expiry)) {
-		if (!IS_ENABLED(CONFIG_NO_HZ_COMMON))
-			return;
-		/* CPU is awake, so check the deferrable base. */
-		base++;
-		if (time_before(jiffies, base->next_expiry))
+
+	for (int i = 0; i < NR_BASES; i++, base++) {
+		/* Raise the softirq only if required. */
+		if (time_after_eq(jiffies, base->next_expiry)) {
+			raise_softirq(TIMER_SOFTIRQ);
 			return;
+		}
 	}
-	raise_softirq(TIMER_SOFTIRQ);
 }
 
 /*
-- 
2.39.2