From: Sebastian Andrzej Siewior Date: Fri, 11 Jan 2019 21:16:31 +0100 Subject: [PATCH 146/351] rtmutex/rwlock: preserve state like a sleeping lock Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=0c6ae3427e4d697b6c663c992da53d43f4e9c9e3 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 Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior --- 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 aebb7ce25bc6..8f90afe111ce 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