From 139ca04ee572fea6c0c105e88aba3a534efcd7c4 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:17 -0400 Subject: [PATCH] locks: convert fl_link to a hlist_node Testing has shown that iterating over the blocked_list for deadlock detection turns out to be a bottleneck. In order to alleviate that, begin the process of turning it into a hashtable. We start by turning the fl_link into a hlist_node and the global lists into hlists. A later patch will do the conversion of the blocked_list to a hashtable. Signed-off-by: Jeff Layton Acked-by: J. Bruce Fields Signed-off-by: Al Viro --- fs/locks.c | 24 ++++++++++++------------ include/linux/fs.h | 2 +- 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 84e269fc4c69..941b7146b6be 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -157,13 +157,13 @@ int lease_break_time = 45; * The global file_lock_list is only used for displaying /proc/locks. Protected * by the file_lock_lock. */ -static LIST_HEAD(file_lock_list); +static HLIST_HEAD(file_lock_list); /* * The blocked_list is used to find POSIX lock loops for deadlock detection. * Protected by file_lock_lock. */ -static LIST_HEAD(blocked_list); +static HLIST_HEAD(blocked_list); /* * This lock protects the blocked_list, and the file_lock_list. Generally, if @@ -188,7 +188,7 @@ static struct kmem_cache *filelock_cache __read_mostly; static void locks_init_lock_heads(struct file_lock *fl) { - INIT_LIST_HEAD(&fl->fl_link); + INIT_HLIST_NODE(&fl->fl_link); INIT_LIST_HEAD(&fl->fl_block); init_waitqueue_head(&fl->fl_wait); } @@ -222,7 +222,7 @@ void locks_free_lock(struct file_lock *fl) { BUG_ON(waitqueue_active(&fl->fl_wait)); BUG_ON(!list_empty(&fl->fl_block)); - BUG_ON(!list_empty(&fl->fl_link)); + BUG_ON(!hlist_unhashed(&fl->fl_link)); locks_release_private(fl); kmem_cache_free(filelock_cache, fl); @@ -500,7 +500,7 @@ static inline void locks_insert_global_locks(struct file_lock *fl) { spin_lock(&file_lock_lock); - list_add_tail(&fl->fl_link, &file_lock_list); + hlist_add_head(&fl->fl_link, &file_lock_list); spin_unlock(&file_lock_lock); } @@ -508,20 +508,20 @@ static inline void locks_delete_global_locks(struct file_lock *fl) { spin_lock(&file_lock_lock); - list_del_init(&fl->fl_link); + hlist_del_init(&fl->fl_link); spin_unlock(&file_lock_lock); } static inline void locks_insert_global_blocked(struct file_lock *waiter) { - list_add(&waiter->fl_link, &blocked_list); + hlist_add_head(&waiter->fl_link, &blocked_list); } static inline void locks_delete_global_blocked(struct file_lock *waiter) { - list_del_init(&waiter->fl_link); + hlist_del_init(&waiter->fl_link); } /* Remove waiter from blocker's block list. @@ -748,7 +748,7 @@ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) { struct file_lock *fl; - list_for_each_entry(fl, &blocked_list, fl_link) { + hlist_for_each_entry(fl, &blocked_list, fl_link) { if (posix_same_owner(fl, block_fl)) return fl->fl_next; } @@ -2300,7 +2300,7 @@ static int locks_show(struct seq_file *f, void *v) { struct file_lock *fl, *bfl; - fl = list_entry(v, struct file_lock, fl_link); + fl = hlist_entry(v, struct file_lock, fl_link); lock_get_status(f, fl, *((loff_t *)f->private), ""); @@ -2316,14 +2316,14 @@ static void *locks_start(struct seq_file *f, loff_t *pos) spin_lock(&file_lock_lock); *p = (*pos + 1); - return seq_list_start(&file_lock_list, *pos); + return seq_hlist_start(&file_lock_list, *pos); } static void *locks_next(struct seq_file *f, void *v, loff_t *pos) { loff_t *p = f->private; ++*p; - return seq_list_next(v, &file_lock_list, pos); + return seq_hlist_next(v, &file_lock_list, pos); } static void locks_stop(struct seq_file *f, void *v) diff --git a/include/linux/fs.h b/include/linux/fs.h index 24fe998795e1..fab064a3b65f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -946,7 +946,7 @@ int locks_in_grace(struct net *); */ struct file_lock { struct file_lock *fl_next; /* singly linked list for this inode */ - struct list_head fl_link; /* doubly linked list of all locks */ + struct hlist_node fl_link; /* node in global lists */ struct list_head fl_block; /* circular list of blocked processes */ fl_owner_t fl_owner; unsigned int fl_flags;