From: Mike Galbraith <efault@gmx.de>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org,
mingo@kernel.org, xlpang@redhat.com, tglx@linutronix.de,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [tip:locking/core] rtmutex: Deboost before waking up the top waiter
Date: Wed, 05 Apr 2017 10:08:27 +0200 [thread overview]
Message-ID: <1491379707.6538.2.camel@gmx.de> (raw)
In-Reply-To: <tip-2a1c6029940675abb2217b590512dbf691867ec4@git.kernel.org>
locking/rtmutex: Fix preempt leak in __rt_mutex_futex_unlock()
mark_wakeup_next_waiter() already disables preemption, doing so
again leaves us with an unpaired preempt_disable().
Signed-off-by: Mike Galbraith <efault@gmx.de>
---
kernel/locking/rtmutex.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1581,13 +1581,13 @@ bool __sched __rt_mutex_futex_unlock(str
return false; /* done */
}
- mark_wakeup_next_waiter(wake_q, lock);
/*
- * We've already deboosted, retain preempt_disabled when dropping
- * the wait_lock to avoid inversion until the wakeup. Matched
- * by rt_mutex_postunlock();
+ * We've already deboosted, mark_wakeup_next_waiter() will
+ * retain preempt_disabled when we drop the wait_lock, to
+ * avoid inversion prior to the wakeup. preempt_disable()
+ * therein pairs with rt_mutex_postunlock().
*/
- preempt_disable();
+ mark_wakeup_next_waiter(wake_q, lock);
return true; /* call postunlock() */
}
next prev parent reply other threads:[~2017-04-05 8:10 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-23 14:56 [PATCH -v3 0/8] PI vs SCHED_DEADLINE fixes Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 1/8] rtmutex: Deboost before waking up the top waiter Peter Zijlstra
2017-04-04 9:48 ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-04-05 8:08 ` Mike Galbraith [this message]
2017-04-05 14:55 ` [tip:locking/core] Retiplockingcore_rtmutex_Deboost_before_waking_up_the_top_waiter tip-bot for Mike Galbraith
2017-04-05 15:03 ` [tip:locking/core] rtmutex: Plug preempt count leak in rt_mutex_futex_unlock() tip-bot for Mike Galbraith
2017-04-06 6:16 ` [tip:locking/core] rtmutex: Deboost before waking up the top waiter Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 2/8] sched/rtmutex/deadline: Fix a PI crash for deadline tasks Peter Zijlstra
2017-04-04 9:49 ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 3/8] sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update Peter Zijlstra
2017-04-04 9:50 ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 4/8] rtmutex: Clean up Peter Zijlstra
2017-03-23 18:21 ` Steven Rostedt
2017-04-04 9:50 ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 5/8] sched/rtmutex: Refactor rt_mutex_setprio() Peter Zijlstra
2017-04-04 9:51 ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 6/8] sched,tracing: Update trace_sched_pi_setprio() Peter Zijlstra
2017-04-04 9:51 ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 7/8] rtmutex: Fix PI chain order integrity Peter Zijlstra
2017-04-04 9:52 ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 8/8] rtmutex: Fix more prio comparisons Peter Zijlstra
2017-04-04 9:52 ` [tip:locking/core] " tip-bot for Peter Zijlstra
-- strict thread matches above, loose matches on Subject: below --
2016-04-14 11:37 [PATCH v3 0/6] sched/deadline/rtmutex: Fix two deadline PI issues Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 1/6] rtmutex: Deboost before waking up the top waiter Xunlei Pang
2016-04-18 8:23 ` Thomas Gleixner
2016-04-18 8:44 ` Xunlei Pang
2016-04-18 9:02 ` Thomas Gleixner
2016-04-18 9:41 ` Xunlei Pang
2016-04-20 12:20 ` Peter Zijlstra
2016-04-20 12:43 ` Thomas Gleixner
2016-04-20 13:10 ` Peter Zijlstra
2016-04-14 11:37 ` [PATCH v3 2/6] sched/rtmutex/deadline: Fix a PI crash for deadline tasks Xunlei Pang
2016-04-20 13:19 ` Peter Zijlstra
2016-04-20 13:49 ` Xunlei Pang
2016-04-22 3:26 ` Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 3/6] rtmutex: Move "rt_mutex_waiter" definition to "include/linux/rtmutex.h" Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 4/6] sched: Move dl_policy() to "include/linux/sched.h" Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 5/6] sched/deadline/rtmutex: Fix unprotected PI access in enqueue_task_dl() Xunlei Pang
2016-04-14 15:31 ` Peter Zijlstra
2016-04-15 1:58 ` Xunlei Pang
2016-04-15 2:19 ` Xunlei Pang
2016-04-20 12:25 ` Peter Zijlstra
2016-04-20 13:00 ` Xunlei Pang
2016-04-20 13:17 ` Peter Zijlstra
2016-04-20 13:45 ` Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 6/6] sched/deadline/rtmutex: Don't miss the dl_runtime/dl_period update Xunlei Pang
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