diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-07-08 14:24:16 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-07-03 19:48:08 -0700 |
| commit | 2a7abb5a0b35ca8f7c9f8113322fbff87b5d6667 (patch) | |
| tree | 0952d0b787ed15634b1bbb463c145854af41021f | |
| parent | b3d78448444995411ba87af2237391bf68fc358d (diff) | |
fput: turn "list_head delayed_fput_list" into llist_head
commit 4f5e65a1cc90bbb15b9f6cdc362922af1bcc155a upstream.
fput() and delayed_fput() can use llist and avoid the locking.
This is unlikely path, it is not that this change can improve
the performance, but this way the code looks simpler.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Wang Kai <morgan.wang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/file_table.c | 25 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
2 files changed, 12 insertions, 15 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index 54a34be444f9..cd4ef34bb641 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -265,18 +265,15 @@ static void __fput(struct file *file) mntput(mnt); } -static DEFINE_SPINLOCK(delayed_fput_lock); -static LIST_HEAD(delayed_fput_list); +static LLIST_HEAD(delayed_fput_list); static void delayed_fput(struct work_struct *unused) { - LIST_HEAD(head); - spin_lock_irq(&delayed_fput_lock); - list_splice_init(&delayed_fput_list, &head); - spin_unlock_irq(&delayed_fput_lock); - while (!list_empty(&head)) { - struct file *f = list_first_entry(&head, struct file, f_u.fu_list); - list_del_init(&f->f_u.fu_list); - __fput(f); + struct llist_node *node = llist_del_all(&delayed_fput_list); + struct llist_node *next; + + for (; node; node = next) { + next = llist_next(node); + __fput(llist_entry(node, struct file, f_u.fu_llist)); } } @@ -306,7 +303,6 @@ void fput(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { struct task_struct *task = current; - unsigned long flags; file_sb_list_del(file); if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { @@ -314,10 +310,9 @@ void fput(struct file *file) if (!task_work_add(task, &file->f_u.fu_rcuhead, true)) return; } - spin_lock_irqsave(&delayed_fput_lock, flags); - list_add(&file->f_u.fu_list, &delayed_fput_list); - schedule_work(&delayed_fput_work); - spin_unlock_irqrestore(&delayed_fput_lock, flags); + + if (llist_add(&file->f_u.fu_llist, &delayed_fput_list)) + schedule_work(&delayed_fput_work); } } diff --git a/include/linux/fs.h b/include/linux/fs.h index d57bc5df7225..f45857a7ac49 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -10,6 +10,7 @@ #include <linux/stat.h> #include <linux/cache.h> #include <linux/list.h> +#include <linux/llist.h> #include <linux/radix-tree.h> #include <linux/rbtree.h> #include <linux/init.h> @@ -767,6 +768,7 @@ struct file { */ union { struct list_head fu_list; + struct llist_node fu_llist; struct rcu_head fu_rcuhead; } f_u; struct path f_path; |