[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20201204170805.430113367@linutronix.de>
Date: Fri, 04 Dec 2020 18:01:58 +0100
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
Frederic Weisbecker <frederic@...nel.org>,
Paul McKenney <paulmck@...nel.org>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Subject: [patch V2 7/9] softirq: Replace barrier() with cpu_relax() in
tasklet_unlock_wait()
From: Thomas Gleixner <tglx@...utronix.de>
A barrier() in a tight loop which waits for something to happen on a remote
CPU is a pointless exercise. Replace it with cpu_relax() which allows HT
siblings to make progress.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
include/linux/interrupt.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -668,7 +668,8 @@ static inline void tasklet_unlock(struct
static inline void tasklet_unlock_wait(struct tasklet_struct *t)
{
- while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
+ while (test_bit(TASKLET_STATE_RUN, &(t)->state))
+ cpu_relax();
}
#else
#define tasklet_trylock(t) 1
Powered by blists - more mailing lists