From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Sebastian Siewior <bigeasy@linutronix.de>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Julia Cartwright <julia@ni.com>
Subject: [patch 2/7] timerfd: Prepare for PREEMPT_RT
Date: Wed, 31 Jul 2019 00:33:50 +0200 [thread overview]
Message-ID: <20190730223828.600085866@linutronix.de> (raw)
In-Reply-To: 20190730223348.409366334@linutronix.de
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>
---
fs/timerfd.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -471,7 +471,11 @@ static int do_timerfd_settime(int ufd, i
break;
}
spin_unlock_irq(&ctx->wqh.lock);
- cpu_relax();
+
+ if (isalarm(ctx))
+ hrtimer_cancel_wait_running(&ctx->t.alarm.timer);
+ else
+ hrtimer_cancel_wait_running(&ctx->t.tmr);
}
/*
next prev parent reply other threads:[~2019-07-30 22:40 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:timers/core] " tip-bot for Anna-Maria Gleixner
2019-08-01 19:06 ` tip-bot for Anna-Maria Gleixner
2019-07-30 22:33 ` Thomas Gleixner [this message]
2019-08-01 16:04 ` [tip:timers/core] timerfd: " 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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