From 820249bafe441dce5336ad544a5e709df42fceb5 Mon Sep 17 00:00:00 2001 From: John McCutchan Date: Tue, 6 Sep 2005 15:16:38 -0700 Subject: [PATCH] [PATCH] inotify speedup Bypass an inotify-related fastpath spinlock and several function calls on systems which have no inotify watches registered. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/inotify.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/inotify.c b/fs/inotify.c index 2e4e2a57708..2fd97ef547f 100644 --- a/fs/inotify.c +++ b/fs/inotify.c @@ -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_watch(struct inotify_device *dev, 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 inotify_watch *watch, 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(struct dentry *dentry, u32 mask, 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), -- 2.20.1