From: Tom Zanussi <zanussi@kernel.org>
To: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Cc: rostedt@goodmis.org, tglx@linutronix.de, C.Emde@osadl.org,
jkacur@redhat.com, bigeasy@linutronix.de,
daniel.wagner@siemens.com, julia@ni.com, amartin@nvidia.com
Subject: [PATCH 05/13] rtmutex/rwlock: preserve state like a sleeping lock
Date: Mon, 8 Apr 2019 14:14:07 -0500 [thread overview]
Message-ID: <784bd79865718c40cd2564db00f430ae6ac014da.1554737688.git.tom.zanussi@linux.intel.com> (raw)
In-Reply-To: <cover.1554737688.git.tom.zanussi@linux.intel.com>
In-Reply-To: <cover.1554737688.git.tom.zanussi@linux.intel.com>
4.14.109-rt58-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 4a1bf9e54a013d55ab156cb462c68054cb52ee2d ]
The rwlock is spinning while acquiring a lock. Therefore it must become
a sleeping lock on RT and preserve its task state while sleeping and
waiting for the lock to become available.
Reported-by: Joe Korty <Joe.Korty@concurrent-rt.com>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/locking/rwlock-rt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c
index f2e155b2c4a8..c3b91205161c 100644
--- a/kernel/locking/rwlock-rt.c
+++ b/kernel/locking/rwlock-rt.c
@@ -128,7 +128,7 @@ void __sched __read_rt_lock(struct rt_rw_lock *lock)
* That would put Reader1 behind the writer waiting on
* Reader2 to call read_unlock() which might be unbound.
*/
- rt_mutex_init_waiter(&waiter, false);
+ rt_mutex_init_waiter(&waiter, true);
rt_spin_lock_slowlock_locked(m, &waiter, flags);
/*
* The slowlock() above is guaranteed to return with the rtmutex is
--
2.14.1
next prev parent reply other threads:[~2019-04-08 19:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-08 19:14 [PATCH 00/13] Linux 4.14.109-rt58-rc1 Tom Zanussi
2019-04-08 19:14 ` [PATCH 01/13] arm64: fpsimd: use preemp_disable in addition to local_bh_disable() Tom Zanussi
2019-04-08 19:14 ` [PATCH 02/13] sched/fair: Robustify CFS-bandwidth timer locking Tom Zanussi
2019-04-08 19:14 ` [PATCH 03/13] sched/fair: Make the hrtimers non-hard again Tom Zanussi
2019-04-08 19:14 ` [PATCH 04/13] locking/rt-mutex: Flush block plug on __down_read() Tom Zanussi
2019-04-08 19:14 ` Tom Zanussi [this message]
2019-04-08 19:14 ` [PATCH 06/13] softirq: Avoid "local_softirq_pending" messages if ksoftirqd is blocked Tom Zanussi
2019-04-08 19:14 ` [PATCH 07/13] softirq: Avoid "local_softirq_pending" messages if task is in cpu_chill() Tom Zanussi
2019-04-08 19:14 ` [PATCH 08/13] hrtimer: Don't lose state " Tom Zanussi
2019-04-08 19:14 ` [PATCH 09/13] x86: lazy-preempt: properly check against preempt-mask Tom Zanussi
2019-04-08 19:14 ` [PATCH 10/13] hrtimer: cpu_chill(): save task state in ->saved_state() Tom Zanussi
2019-04-08 19:14 ` [PATCH 11/13] tty/sysrq: Convert show_lock to raw_spinlock_t Tom Zanussi
2019-04-08 19:14 ` [PATCH 12/13] powerpc/pseries/iommu: Use a locallock instead local_irq_save() Tom Zanussi
2019-04-08 19:14 ` [PATCH 13/13] Linux 4.14.109-rt58 Tom Zanussi
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