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From: tip-bot for Anna-Maria Gleixner <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: bigeasy@linutronix.de, anna-maria@linutronix.de,
	linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com,
	peterz@infradead.org, tglx@linutronix.de
Subject: [tip:timers/core] alarmtimer: Prepare for PREEMPT_RT
Date: Thu, 1 Aug 2019 09:04:08 -0700	[thread overview]
Message-ID: <tip-1f8e8bd8b74c8089a43bc5f1f24e4bf0f855d760@git.kernel.org> (raw)
In-Reply-To: <20190730223828.508744705@linutronix.de>

Commit-ID:  1f8e8bd8b74c8089a43bc5f1f24e4bf0f855d760
Gitweb:     https://git.kernel.org/tip/1f8e8bd8b74c8089a43bc5f1f24e4bf0f855d760
Author:     Anna-Maria Gleixner <anna-maria@linutronix.de>
AuthorDate: Wed, 31 Jul 2019 00:33:49 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 1 Aug 2019 17:46:41 +0200

alarmtimer: Prepare for PREEMPT_RT

Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent
priority inversion and live locks on PREEMPT_RT.

[ tglx: Split out of combo patch ]

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190730223828.508744705@linutronix.de

---
 kernel/time/alarmtimer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 57518efc3810..36947449dba2 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -432,7 +432,7 @@ int alarm_cancel(struct alarm *alarm)
 		int ret = alarm_try_to_cancel(alarm);
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		hrtimer_cancel_wait_running(&alarm->timer);
 	}
 }
 EXPORT_SYMBOL_GPL(alarm_cancel);

  reply	other threads:[~2019-08-01 16:04 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-30 22:33 [patch 0/7] posix-timers: Prepare for PREEMPT_RT - part 1 Thomas Gleixner
2019-07-30 22:33 ` [patch 1/7] alarmtimer: Prepare for PREEMPT_RT Thomas Gleixner
2019-08-01 16:04   ` tip-bot for Anna-Maria Gleixner [this message]
2019-08-01 19:06   ` [tip:timers/core] " tip-bot for Anna-Maria Gleixner
2019-07-30 22:33 ` [patch 2/7] timerfd: " Thomas Gleixner
2019-08-01 16:04   ` [tip:timers/core] " tip-bot for Anna-Maria Gleixner
2019-08-01 19:07   ` tip-bot for Anna-Maria Gleixner
2019-07-30 22:33 ` [patch 3/7] itimers: " Thomas Gleixner
2019-08-01 16:05   ` [tip:timers/core] " tip-bot for Anna-Maria Gleixner
2019-08-01 19:07   ` tip-bot for Anna-Maria Gleixner
2019-07-30 22:33 ` [patch 4/7] posix-timers: Cleanup the flag/flags confusion Thomas Gleixner
2019-08-01 16:06   ` [tip:timers/core] " tip-bot for Anna-Maria Gleixner
2019-08-01 19:08   ` tip-bot for Thomas Gleixner
2019-07-30 22:33 ` [patch 5/7] posix-timers: Rework cancel retry loops Thomas Gleixner
2019-08-01 16:07   ` [tip:timers/core] " tip-bot for Thomas Gleixner
2019-08-01 19:09   ` tip-bot for Thomas Gleixner
2019-07-30 22:33 ` [patch 6/7] posix-timers: Move rcu_head out of it union Thomas Gleixner
2019-08-01 16:08   ` [tip:timers/core] " tip-bot for Sebastian Andrzej Siewior
2019-08-01 19:09   ` tip-bot for Sebastian Andrzej Siewior
2019-07-30 22:33 ` [patch 7/7] posix-timers: Prepare for PREEMPT_RT Thomas Gleixner
2019-07-31  9:49   ` Peter Zijlstra
2019-07-31 11:03     ` Thomas Gleixner
2019-08-01 16:08   ` [tip:timers/core] " tip-bot for Thomas Gleixner
2019-08-01 19:10   ` tip-bot for Thomas Gleixner
2019-07-31  9:49 ` [patch 0/7] posix-timers: Prepare for PREEMPT_RT - part 1 Peter Zijlstra

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