From: John McCutchan Bypass an inotify-related fastpath spinlock and several function calls on systems which have no inotify watches registered. Signed-off-by: Andrew Morton --- fs/inotify.c | 7 +++++++ 1 files changed, 7 insertions(+) diff -puN fs/inotify.c~inotify-speedup fs/inotify.c --- devel/fs/inotify.c~inotify-speedup 2005-08-06 15:34:46.000000000 -0700 +++ devel-akpm/fs/inotify.c 2005-08-06 15:34:46.000000000 -0700 @@ -37,6 +37,7 @@ #include static atomic_t inotify_cookie; +static atomic_t inotify_watches; static kmem_cache_t *watch_cachep; static kmem_cache_t *event_cachep; @@ -422,6 +423,7 @@ static struct inotify_watch *create_watc get_inotify_watch(watch); atomic_inc(&dev->user->inotify_watches); + atomic_inc(&inotify_watches); return watch; } @@ -454,6 +456,7 @@ static void remove_watch_no_event(struct list_del(&watch->d_list); atomic_dec(&dev->user->inotify_watches); + atomic_dec(&inotify_watches); idr_remove(&dev->idr, watch->wd); put_inotify_watch(watch); } @@ -532,6 +535,9 @@ void inotify_dentry_parent_queue_event(s struct dentry *parent; struct inode *inode; + if (!atomic_read (&inotify_watches)) + return; + spin_lock(&dentry->d_lock); parent = dentry->d_parent; inode = parent->d_inode; @@ -1043,6 +1049,7 @@ static int __init inotify_setup(void) inotify_max_user_watches = 8192; atomic_set(&inotify_cookie, 0); + atomic_set(&inotify_watches, 0); watch_cachep = kmem_cache_create("inotify_watch_cache", sizeof(struct inotify_watch), _