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| author | Waiman Long <longman@redhat.com> | 2019-05-20 16:59:12 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-06-17 12:28:06 +0200 |
| commit | 94a9717b3c40e77a54e4afacd8f19a9a86bfeead (patch) | |
| tree | 66551a1dfa95af0602b4d2cec3559deb03d7be43 /include/linux/percpu-rwsem.h | |
| parent | cf69482d62d996d3ce840eeead8e160de281ac6c (diff) | |
| download | lwn-94a9717b3c40e77a54e4afacd8f19a9a86bfeead.tar.gz lwn-94a9717b3c40e77a54e4afacd8f19a9a86bfeead.zip | |
locking/rwsem: Make rwsem->owner an atomic_long_t
The rwsem->owner contains not just the task structure pointer, it also
holds some flags for storing the current state of the rwsem. Some of
the flags may have to be atomically updated. To reflect the new reality,
the owner is now changed to an atomic_long_t type.
New helper functions are added to properly separate out the task
structure pointer and the embedded flags.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-14-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/percpu-rwsem.h')
| -rw-r--r-- | include/linux/percpu-rwsem.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 03cb4b6f842e..0a43830f1932 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -117,7 +117,7 @@ static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem, lock_release(&sem->rw_sem.dep_map, 1, ip); #ifdef CONFIG_RWSEM_SPIN_ON_OWNER if (!read) - sem->rw_sem.owner = RWSEM_OWNER_UNKNOWN; + atomic_long_set(&sem->rw_sem.owner, RWSEM_OWNER_UNKNOWN); #endif } @@ -127,7 +127,7 @@ static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem, lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip); #ifdef CONFIG_RWSEM_SPIN_ON_OWNER if (!read) - sem->rw_sem.owner = current; + atomic_long_set(&sem->rw_sem.owner, (long)current); #endif } |