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author | Oleg Nesterov <oleg@redhat.com> | 2013-07-08 23:24:16 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-07-13 11:29:10 +0200 |
commit | 4f5e65a1cc90bbb15b9f6cdc362922af1bcc155a (patch) | |
tree | c635e87d98c9961ad95c2351bae6d9609eeb761f /fs | |
parent | fs/file_table.c:fput(): add comment (diff) | |
download | linux-4f5e65a1cc90bbb15b9f6cdc362922af1bcc155a.tar.xz linux-4f5e65a1cc90bbb15b9f6cdc362922af1bcc155a.zip |
fput: turn "list_head delayed_fput_list" into llist_head
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>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/file_table.c | 25 |
1 files changed, 10 insertions, 15 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index b9a77ad08b4d..b44e4c559786 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))) { @@ -320,10 +316,9 @@ void fput(struct file *file) * fput to avoid leaking *file. */ } - 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); } } |