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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-13 17:27:28 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-13 17:27:28 (GMT) |
commit | cc76ee75a9d3201eeacc576d17fbc1511f673010 (patch) | |
tree | 9505405c270718c491840ae7d0da0521386ce939 /kernel/locking/osq_lock.c | |
parent | 9c65e12a55fea2da50f4069ec0dc47c50b7bd2bb (diff) | |
parent | 58995a9a5b292458f94a2356b8c878230fa56fe0 (diff) | |
download | linux-cc76ee75a9d3201eeacc576d17fbc1511f673010.tar.xz |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking changes from Ingo Molnar:
"Main changes:
- jump label asm preparatory work for PowerPC (Anton Blanchard)
- rwsem optimizations and cleanups (Davidlohr Bueso)
- mutex optimizations and cleanups (Jason Low)
- futex fix (Oleg Nesterov)
- remove broken atomicity checks from {READ,WRITE}_ONCE() (Peter
Zijlstra)"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
powerpc, jump_label: Include linux/jump_label.h to get HAVE_JUMP_LABEL define
jump_label: Allow jump labels to be used in assembly
jump_label: Allow asm/jump_label.h to be included in assembly
locking/mutex: Further simplify mutex_spin_on_owner()
locking: Remove atomicy checks from {READ,WRITE}_ONCE
locking/rtmutex: Rename argument in the rt_mutex_adjust_prio_chain() documentation as well
locking/rwsem: Fix lock optimistic spinning when owner is not running
locking: Remove ACCESS_ONCE() usage
locking/rwsem: Check for active lock before bailing on spinning
locking/rwsem: Avoid deceiving lock spinners
locking/rwsem: Set lock ownership ASAP
locking/rwsem: Document barrier need when waking tasks
locking/futex: Check PF_KTHREAD rather than !p->mm to filter out kthreads
locking/mutex: Refactor mutex_spin_on_owner()
locking/mutex: In mutex_spin_on_owner(), return true when owner changes
Diffstat (limited to 'kernel/locking/osq_lock.c')
-rw-r--r-- | kernel/locking/osq_lock.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c index c112d00..dc85ee2 100644 --- a/kernel/locking/osq_lock.c +++ b/kernel/locking/osq_lock.c @@ -98,7 +98,7 @@ bool osq_lock(struct optimistic_spin_queue *lock) prev = decode_cpu(old); node->prev = prev; - ACCESS_ONCE(prev->next) = node; + WRITE_ONCE(prev->next, node); /* * Normally @prev is untouchable after the above store; because at that @@ -109,7 +109,7 @@ bool osq_lock(struct optimistic_spin_queue *lock) * cmpxchg in an attempt to undo our queueing. */ - while (!ACCESS_ONCE(node->locked)) { + while (!READ_ONCE(node->locked)) { /* * If we need to reschedule bail... so we can block. */ @@ -148,7 +148,7 @@ unqueue: * Or we race against a concurrent unqueue()'s step-B, in which * case its step-C will write us a new @node->prev pointer. */ - prev = ACCESS_ONCE(node->prev); + prev = READ_ONCE(node->prev); } /* @@ -170,8 +170,8 @@ unqueue: * it will wait in Step-A. */ - ACCESS_ONCE(next->prev) = prev; - ACCESS_ONCE(prev->next) = next; + WRITE_ONCE(next->prev, prev); + WRITE_ONCE(prev->next, next); return false; } @@ -193,11 +193,11 @@ void osq_unlock(struct optimistic_spin_queue *lock) node = this_cpu_ptr(&osq_node); next = xchg(&node->next, NULL); if (next) { - ACCESS_ONCE(next->locked) = 1; + WRITE_ONCE(next->locked, 1); return; } next = osq_wait_next(lock, node, NULL); if (next) - ACCESS_ONCE(next->locked) = 1; + WRITE_ONCE(next->locked, 1); } |