Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:41798 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757818Ab3FADIN (ORCPT ); Fri, 31 May 2013 23:08:13 -0400 From: Jeff Layton To: viro@zeniv.linux.org.uk, matthew@wil.cx, bfields@fieldses.org Cc: dhowells@redhat.com, sage@inktank.com, smfrench@gmail.com, swhiteho@redhat.com, Trond.Myklebust@netapp.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, piastryyy@gmail.com Subject: [PATCH v1 08/11] locks: convert fl_link to a hlist_node Date: Fri, 31 May 2013 23:07:31 -0400 Message-Id: <1370056054-25449-9-git-send-email-jlayton@redhat.com> In-Reply-To: <1370056054-25449-1-git-send-email-jlayton@redhat.com> References: <1370056054-25449-1-git-send-email-jlayton@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- fs/locks.c | 32 ++++++++++++++++---------------- include/linux/fs.h | 2 +- 2 files changed, 17 insertions(+), 17 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index fc35b9e..5ed056b 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -163,8 +163,8 @@ int lease_break_time = 45; #define for_each_lock(inode, lockp) \ for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next) -static LIST_HEAD(file_lock_list); -static LIST_HEAD(blocked_list); +static HLIST_HEAD(file_lock_list); +static HLIST_HEAD(blocked_list); /* Protects the two list heads above */ static DEFINE_SPINLOCK(file_lock_lock); @@ -173,7 +173,7 @@ 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); } @@ -207,7 +207,7 @@ 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); @@ -486,7 +486,7 @@ static inline void locks_insert_global_blocked(struct file_lock *waiter) { spin_lock(&file_lock_lock); - list_add(&waiter->fl_link, &blocked_list); + hlist_add_head(&waiter->fl_link, &blocked_list); spin_unlock(&file_lock_lock); } @@ -494,7 +494,7 @@ static inline void locks_delete_global_blocked(struct file_lock *waiter) { spin_lock(&file_lock_lock); - list_del_init(&waiter->fl_link); + hlist_del_init(&waiter->fl_link); spin_unlock(&file_lock_lock); } @@ -502,7 +502,7 @@ static inline void locks_insert_global_locks(struct file_lock *waiter) { spin_lock(&file_lock_lock); - list_add_tail(&waiter->fl_link, &file_lock_list); + hlist_add_head(&waiter->fl_link, &file_lock_list); spin_unlock(&file_lock_lock); } @@ -510,7 +510,7 @@ static inline void locks_delete_global_locks(struct file_lock *waiter) { spin_lock(&file_lock_lock); - list_del_init(&waiter->fl_link); + hlist_del_init(&waiter->fl_link); spin_unlock(&file_lock_lock); } @@ -705,7 +705,7 @@ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) { struct file_lock *fl, *ret = NULL; - 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)) { ret = fl->fl_next; if (likely(ret)) @@ -867,7 +867,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str goto out; error = FILE_LOCK_DEFERRED; locks_insert_block(fl, request); - if (list_empty(&request->fl_link)) + if (hlist_unhashed(&request->fl_link)) locks_insert_global_blocked(request); goto out; } @@ -882,10 +882,10 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str * Now that we know the request is no longer blocked, we can take it * off the global list. Some callers send down partially initialized * requests, so we only do this if FL_SLEEP is set. Also, avoid taking - * the lock if the list is empty, as that indicates a request that + * the lock if the hlist is unhashed, as that indicates a request that * never blocked. */ - if ((request->fl_flags & FL_SLEEP) && !list_empty(&request->fl_link)) + if ((request->fl_flags & FL_SLEEP) && !hlist_unhashed(&request->fl_link)) locks_delete_global_blocked(request); /* @@ -2277,11 +2277,11 @@ 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), ""); - list_for_each_entry(bfl, &blocked_list, fl_link) { + hlist_for_each_entry(bfl, &blocked_list, fl_link) { if (bfl->fl_next == fl) lock_get_status(f, bfl, *((loff_t *)f->private), " ->"); } @@ -2295,14 +2295,14 @@ 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 ccb44ea..07a009e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -934,7 +934,7 @@ 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; -- 1.7.1