From fbe9cc4a87030d5cad5f944ffaef6af7efd119e4 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 13 Dec 2005 23:26:29 -0800 Subject: [PATCH] [AF_UNIX]: Use spinlock for unix_table_lock This lock is actually taken mostly as a writer, so using a rwlock actually just makes performance worse especially on chips like the Intel P4. Signed-off-by: David S. Miller --- include/net/af_unix.h | 2 +- net/unix/af_unix.c | 34 +++++++++++++++++----------------- net/unix/garbage.c | 4 ++-- 3 files changed, 20 insertions(+), 20 deletions(-) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index b5d785ab4a0..3f302ae98c0 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -13,7 +13,7 @@ extern void unix_gc(void); #define UNIX_HASH_SIZE 256 extern struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; -extern rwlock_t unix_table_lock; +extern spinlock_t unix_table_lock; extern atomic_t unix_tot_inflight; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 1dc3685048f..04e850e04e3 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -121,7 +121,7 @@ int sysctl_unix_max_dgram_qlen = 10; struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; -DEFINE_RWLOCK(unix_table_lock); +DEFINE_SPINLOCK(unix_table_lock); static atomic_t unix_nr_socks = ATOMIC_INIT(0); #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) @@ -130,7 +130,7 @@ static atomic_t unix_nr_socks = ATOMIC_INIT(0); /* * SMP locking strategy: - * hash table is protected with rwlock unix_table_lock + * hash table is protected with spinlock unix_table_lock * each socket state is protected by separate rwlock. */ @@ -214,16 +214,16 @@ static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) static inline void unix_remove_socket(struct sock *sk) { - write_lock(&unix_table_lock); + spin_lock(&unix_table_lock); __unix_remove_socket(sk); - write_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); } static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) { - write_lock(&unix_table_lock); + spin_lock(&unix_table_lock); __unix_insert_socket(list, sk); - write_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); } static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname, @@ -250,11 +250,11 @@ static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname, { struct sock *s; - read_lock(&unix_table_lock); + spin_lock(&unix_table_lock); s = __unix_find_socket_byname(sunname, len, type, hash); if (s) sock_hold(s); - read_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); return s; } @@ -263,7 +263,7 @@ static struct sock *unix_find_socket_byinode(struct inode *i) struct sock *s; struct hlist_node *node; - read_lock(&unix_table_lock); + spin_lock(&unix_table_lock); sk_for_each(s, node, &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { struct dentry *dentry = unix_sk(s)->dentry; @@ -276,7 +276,7 @@ static struct sock *unix_find_socket_byinode(struct inode *i) } s = NULL; found: - read_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); return s; } @@ -642,12 +642,12 @@ retry: addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0)); - write_lock(&unix_table_lock); + spin_lock(&unix_table_lock); ordernum = (ordernum+1)&0xFFFFF; if (__unix_find_socket_byname(addr->name, addr->len, sock->type, addr->hash)) { - write_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); /* Sanity yield. It is unusual case, but yet... */ if (!(ordernum&0xFF)) yield(); @@ -658,7 +658,7 @@ retry: __unix_remove_socket(sk); u->addr = addr; __unix_insert_socket(&unix_socket_table[addr->hash], sk); - write_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); err = 0; out: up(&u->readsem); @@ -791,7 +791,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) addr->hash = UNIX_HASH_SIZE; } - write_lock(&unix_table_lock); + spin_lock(&unix_table_lock); if (!sunaddr->sun_path[0]) { err = -EADDRINUSE; @@ -814,7 +814,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) __unix_insert_socket(list, sk); out_unlock: - write_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); out_up: up(&u->readsem); out: @@ -1916,7 +1916,7 @@ static struct sock *unix_seq_idx(int *iter, loff_t pos) static void *unix_seq_start(struct seq_file *seq, loff_t *pos) { - read_lock(&unix_table_lock); + spin_lock(&unix_table_lock); return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1); } @@ -1931,7 +1931,7 @@ static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) static void unix_seq_stop(struct seq_file *seq, void *v) { - read_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); } static int unix_seq_show(struct seq_file *seq, void *v) diff --git a/net/unix/garbage.c b/net/unix/garbage.c index 6ffc64e1712..411802bd4d3 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -182,7 +182,7 @@ void unix_gc(void) if (down_trylock(&unix_gc_sem)) return; - read_lock(&unix_table_lock); + spin_lock(&unix_table_lock); forall_unix_sockets(i, s) { @@ -301,7 +301,7 @@ void unix_gc(void) } u->gc_tree = GC_ORPHAN; } - read_unlock(&unix_table_lock); + spin_unlock(&unix_table_lock); /* * Here we are. Hitlist is filled. Die. -- 2.41.0