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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 14:54:22 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 14:54:22 -0700 |
commit | 1bf7067c6e173dc10411704db48338ed69c05565 (patch) | |
tree | 06d731d9647c525fa598d03d7ec957ff9772ff40 /kernel/locking/rtmutex.c | |
parent | fc934d40178ad4e551a17e2733241d9f29fddd70 (diff) | |
parent | 68722101ec3a0e179408a13708dd020e04f54aab (diff) | |
download | op-kernel-dev-1bf7067c6e173dc10411704db48338ed69c05565.zip op-kernel-dev-1bf7067c6e173dc10411704db48338ed69c05565.tar.gz |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"The main changes are:
- 'qspinlock' support, enabled on x86: queued spinlocks - these are
now the spinlock variant used by x86 as they outperform ticket
spinlocks in every category. (Waiman Long)
- 'pvqspinlock' support on x86: paravirtualized variant of queued
spinlocks. (Waiman Long, Peter Zijlstra)
- 'qrwlock' support, enabled on x86: queued rwlocks. Similar to
queued spinlocks, they are now the variant used by x86:
CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
CONFIG_QUEUED_SPINLOCKS=y
CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
CONFIG_QUEUED_RWLOCKS=y
- various lockdep fixlets
- various locking primitives cleanups, further WRITE_ONCE()
propagation"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
locking/lockdep: Remove hard coded array size dependency
locking/qrwlock: Don't contend with readers when setting _QW_WAITING
lockdep: Do not break user-visible string
locking/arch: Rename set_mb() to smp_store_mb()
locking/arch: Add WRITE_ONCE() to set_mb()
rtmutex: Warn if trylock is called from hard/softirq context
arch: Remove __ARCH_HAVE_CMPXCHG
locking/rtmutex: Drop usage of __HAVE_ARCH_CMPXCHG
locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS
locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKS
locking/pvqspinlock: Replace xchg() by the more descriptive set_mb()
locking/pvqspinlock, x86: Enable PV qspinlock for Xen
locking/pvqspinlock, x86: Enable PV qspinlock for KVM
locking/pvqspinlock, x86: Implement the paravirt qspinlock call patching
locking/pvqspinlock: Implement simple paravirt support for the qspinlock
locking/qspinlock: Revert to test-and-set on hypervisors
locking/qspinlock: Use a simple write to grab the lock
locking/qspinlock: Optimize for smaller NR_CPUS
locking/qspinlock: Extract out code snippets for the next patch
locking/qspinlock: Add pending bit
...
Diffstat (limited to 'kernel/locking/rtmutex.c')
-rw-r--r-- | kernel/locking/rtmutex.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index b025295..30ec5b4 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -70,10 +70,10 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) } /* - * We can speed up the acquire/release, if the architecture - * supports cmpxchg and if there's no debugging state to be set up + * We can speed up the acquire/release, if there's no debugging state to be + * set up. */ -#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES) +#ifndef CONFIG_DEBUG_RT_MUTEXES # define rt_mutex_cmpxchg(l,c,n) (cmpxchg(&l->owner, c, n) == c) static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) { @@ -1443,10 +1443,17 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); * * @lock: the rt_mutex to be locked * + * This function can only be called in thread context. It's safe to + * call it from atomic regions, but not from hard interrupt or soft + * interrupt context. + * * Returns 1 on success and 0 on contention */ int __sched rt_mutex_trylock(struct rt_mutex *lock) { + if (WARN_ON(in_irq() || in_nmi() || in_serving_softirq())) + return 0; + return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); } EXPORT_SYMBOL_GPL(rt_mutex_trylock); |