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| author | Maarten Lankhorst <m.b.lankhorst@gmail.com> | 2013-03-08 16:07:27 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-25 10:42:36 -0700 |
| commit | 3db3c62584fbafee52a068035cc4c57e7b921acf (patch) | |
| tree | b4d77f9833981ec5a089a3f29672dfce44687c4c /fs/sysfs | |
| parent | 91721197def2fc69abf152c47dbb87eed0f13333 (diff) | |
| download | linux-3db3c62584fbafee52a068035cc4c57e7b921acf.tar.gz linux-3db3c62584fbafee52a068035cc4c57e7b921acf.tar.bz2 linux-3db3c62584fbafee52a068035cc4c57e7b921acf.zip | |
sysfs: use atomic_inc_unless_negative in sysfs_get_active
It seems that sysfs has an interesting way of doing the same thing.
This removes the cpu_relax unfortunately, but if it's really needed,
it would be better to add this to include/linux/atomic.h to benefit
all atomic ops users.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/dir.c | 17 |
1 files changed, 2 insertions, 15 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 2fbdff6be25c..7f968ede20d6 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -165,21 +165,8 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) if (unlikely(!sd)) return NULL; - while (1) { - int v, t; - - v = atomic_read(&sd->s_active); - if (unlikely(v < 0)) - return NULL; - - t = atomic_cmpxchg(&sd->s_active, v, v + 1); - if (likely(t == v)) - break; - if (t < 0) - return NULL; - - cpu_relax(); - } + if (!atomic_inc_unless_negative(&sd->s_active)) + return NULL; if (likely(!ignore_lockdep(sd))) rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); |