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| author | Jiri Kosina <jkosina@suse.cz> | 2013-01-11 14:31:56 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-11 14:54:55 -0800 |
| commit | 1b963c81b14509e330e0fe3218b645ece2738dc5 (patch) | |
| tree | 5179a29d62e7283c8a1d764e7e320490c4352aeb | |
| parent | fef6c12e8874279ebebfa4cd58d735f6adce3ed1 (diff) | |
| download | linux-1b963c81b14509e330e0fe3218b645ece2738dc5.tar.gz linux-1b963c81b14509e330e0fe3218b645ece2738dc5.tar.xz | |
lockdep, rwsem: provide down_write_nest_lock()
down_write_nest_lock() provides a means to annotate locking scenario
where an outer lock is guaranteed to serialize the order nested locks
are being acquired.
This is analogoue to already existing mutex_lock_nest_lock() and
spin_lock_nest_lock().
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mel Gorman <mel@csn.ul.ie>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/lockdep.h | 3 | ||||
| -rw-r--r-- | include/linux/rwsem.h | 9 | ||||
| -rw-r--r-- | kernel/rwsem.c | 10 |
3 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 00e46376e28f..2bca44b0893c 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -524,14 +524,17 @@ static inline void print_irqtrace_events(struct task_struct *curr) #ifdef CONFIG_DEBUG_LOCK_ALLOC # ifdef CONFIG_PROVE_LOCKING # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) +# define rwsem_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i) # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, NULL, i) # else # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) +# define rwsem_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, i) # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, NULL, i) # endif # define rwsem_release(l, n, i) lock_release(l, n, i) #else # define rwsem_acquire(l, s, t, i) do { } while (0) +# define rwsem_acquire_nest(l, s, t, n, i) do { } while (0) # define rwsem_acquire_read(l, s, t, i) do { } while (0) # define rwsem_release(l, n, i) do { } while (0) #endif diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 54bd7cd7ecbd..413cc11e414a 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -125,8 +125,17 @@ extern void downgrade_write(struct rw_semaphore *sem); */ extern void down_read_nested(struct rw_semaphore *sem, int subclass); extern void down_write_nested(struct rw_semaphore *sem, int subclass); +extern void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest_lock); + +# define down_write_nest_lock(sem, nest_lock) \ +do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \ + _down_write_nest_lock(sem, &(nest_lock)->dep_map); \ +} while (0); + #else # define down_read_nested(sem, subclass) down_read(sem) +# define down_write_nest_lock(sem, nest_lock) down_read(sem) # define down_write_nested(sem, subclass) down_write(sem) #endif diff --git a/kernel/rwsem.c b/kernel/rwsem.c index 6850f53e02d8..b3c6c3fcd847 100644 --- a/kernel/rwsem.c +++ b/kernel/rwsem.c @@ -116,6 +116,16 @@ void down_read_nested(struct rw_semaphore *sem, int subclass) EXPORT_SYMBOL(down_read_nested); +void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) +{ + might_sleep(); + rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_); + + LOCK_CONTENDED(sem, __down_write_trylock, __down_write); +} + +EXPORT_SYMBOL(_down_write_nest_lock); + void down_write_nested(struct rw_semaphore *sem, int subclass) { might_sleep(); |