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From:   Anna-Maria Behnsen <anna-maria@linutronix.de>
To:     linux-kernel@vger.kernel.org
Cc:     Peter Zijlstra <peterz@infradead.org>,
        John Stultz <jstultz@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Eric Dumazet <edumazet@google.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Arjan van de Ven <arjan@infradead.org>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Rik van Riel <riel@surriel.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sebastian Siewior <bigeasy@linutronix.de>,
        Giovanni Gherdovich <ggherdovich@suse.cz>,
        Lukasz Luba <lukasz.luba@arm.com>,
        "Gautham R . Shenoy" <gautham.shenoy@amd.com>,
        Srinivas Pandruvada <srinivas.pandruvada@intel.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        Anna-Maria Behnsen <anna-maria@linutronix.de>,
        Tejun Heo <tj@kernel.org>,
        Lai Jiangshan <jiangshanlai@gmail.com>
Subject: [PATCH v9 18/32] workqueue: Use global variant for add_timer()
Date:   Fri,  1 Dec 2023 10:26:40 +0100
Message-Id: <20231201092654.34614-19-anna-maria@linutronix.de>
In-Reply-To: <20231201092654.34614-1-anna-maria@linutronix.de>
References: <20231201092654.34614-1-anna-maria@linutronix.de>
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The implementation of the NOHZ pull at expiry model will change the timer
bases per CPU. Timers, that have to expire on a specific CPU, require the
TIMER_PINNED flag. If the CPU doesn't matter, the TIMER_PINNED flag must be
dropped. This is required for call sites which use the timer alternately as
pinned and not pinned timer like workqueues do.

Therefore use add_timer_global() to make sure TIMER_PINNED flag is dropped.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
---
v6:
  - New patch: As v6 provides unconditially setting TIMER_PINNED flag in
    add_timer_on() workqueue requires new add_timer_global() variant.
---
 kernel/workqueue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 6e578f576a6f..3a1360794137 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1958,7 +1958,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 	if (unlikely(cpu != WORK_CPU_UNBOUND))
 		add_timer_on(timer, cpu);
 	else
-		add_timer(timer);
+		add_timer_global(timer);
 }
 
 /**
-- 
2.39.2