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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-16 22:41:02 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-16 22:41:02 +0200 |
commit | 3469d261eac65912927dca13ee8f77c744ad7aa2 (patch) | |
tree | 09b25f80c065d52ee6e158c189ba44bb28bb76fc /arch/ia64 | |
parent | Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/k... (diff) | |
parent | locking/rwsem: Fix comment on register clobbering (diff) | |
download | linux-3469d261eac65912927dca13ee8f77c744ad7aa2.tar.xz linux-3469d261eac65912927dca13ee8f77c744ad7aa2.zip |
Merge branch 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull support for killable rwsems from Ingo Molnar:
"This, by Michal Hocko, implements down_write_killable().
The main usecase will be to update mm_sem usage sites to use this new
API, to allow the mm-reaper introduced in commit aac453635549 ("mm,
oom: introduce oom reaper") to tear down oom victim address spaces
asynchronously with minimum latencies and without deadlock worries"
[ The vfs will want it too as the inode lock is changed from a mutex to
a rwsem due to the parallel lookup and readdir updates ]
* 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Fix comment on register clobbering
locking/rwsem: Fix down_write_killable()
locking/rwsem, x86: Add frame annotation for call_rwsem_down_write_failed_killable()
locking/rwsem: Provide down_write_killable()
locking/rwsem, x86: Provide __down_write_killable()
locking/rwsem, s390: Provide __down_write_killable()
locking/rwsem, ia64: Provide __down_write_killable()
locking/rwsem, alpha: Provide __down_write_killable()
locking/rwsem: Introduce basis for down_write_killable()
locking/rwsem, sparc: Drop superfluous arch specific implementation
locking/rwsem, sh: Drop superfluous arch specific implementation
locking/rwsem, xtensa: Drop superfluous arch specific implementation
locking/rwsem: Drop explicit memory barriers
locking/rwsem: Get rid of __down_write_nested()
Diffstat (limited to 'arch/ia64')
-rw-r--r-- | arch/ia64/include/asm/rwsem.h | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h index ce112472bdd6..8b23e070b844 100644 --- a/arch/ia64/include/asm/rwsem.h +++ b/arch/ia64/include/asm/rwsem.h @@ -49,8 +49,8 @@ __down_read (struct rw_semaphore *sem) /* * lock for writing */ -static inline void -__down_write (struct rw_semaphore *sem) +static inline long +___down_write (struct rw_semaphore *sem) { long old, new; @@ -59,10 +59,26 @@ __down_write (struct rw_semaphore *sem) new = old + RWSEM_ACTIVE_WRITE_BIAS; } while (cmpxchg_acq(&sem->count, old, new) != old); - if (old != 0) + return old; +} + +static inline void +__down_write (struct rw_semaphore *sem) +{ + if (___down_write(sem)) rwsem_down_write_failed(sem); } +static inline int +__down_write_killable (struct rw_semaphore *sem) +{ + if (___down_write(sem)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * unlock after reading */ |