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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-16 13:41:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-16 13:41:02 -0700
commit3469d261eac65912927dca13ee8f77c744ad7aa2 (patch)
tree09b25f80c065d52ee6e158c189ba44bb28bb76fc /arch/ia64
parent1c19b68a279c58d6da4379bf8b6d679a300a1daf (diff)
parent4544ba8c6b1743499cabb682897a469911845f15 (diff)
downloadlinux-3469d261eac65912927dca13ee8f77c744ad7aa2.tar.bz2
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.h22
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
*/