From 2f7ca90a0188b57a54d3b1159eb7874427a7e07a Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 21 Jun 2022 10:19:13 -0700 Subject: af_unix: Remove unix_table_locks. unix_table_locks are to protect the global hash table, unix_socket_table. The previous commit removed it, so let's clean up the unnecessary locks. Here is a test result on EC2 c5.9xlarge where 10 processes run concurrently in different netns and bind 100,000 sockets for each. without this series : 1m 38s with this series : 11s It is ~10x faster because the global hash table is split into 10 netns in this case. Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- net/unix/af_unix.c | 42 ++++++++---------------------------------- 1 file changed, 8 insertions(+), 34 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 9d0b07235dbc..49f6626330c3 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -118,13 +118,11 @@ #include "scm.h" -spinlock_t unix_table_locks[UNIX_HASH_SIZE]; -EXPORT_SYMBOL_GPL(unix_table_locks); static atomic_long_t unix_nr_socks; /* SMP locking strategy: - * hash table is protected with spinlock unix_table_locks - * each socket state is protected by separate spin lock. + * hash table is protected with spinlock. + * each socket state is protected by separate spinlock. */ static unsigned int unix_unbound_hash(struct sock *sk) @@ -166,9 +164,6 @@ static void unix_table_double_lock(struct net *net, if (hash1 > hash2) swap(hash1, hash2); - spin_lock(&unix_table_locks[hash1]); - spin_lock_nested(&unix_table_locks[hash2], SINGLE_DEPTH_NESTING); - spin_lock(&net->unx.table.locks[hash1]); spin_lock_nested(&net->unx.table.locks[hash2], SINGLE_DEPTH_NESTING); } @@ -178,9 +173,6 @@ static void unix_table_double_unlock(struct net *net, { spin_unlock(&net->unx.table.locks[hash1]); spin_unlock(&net->unx.table.locks[hash2]); - - spin_unlock(&unix_table_locks[hash1]); - spin_unlock(&unix_table_locks[hash2]); } #ifdef CONFIG_SECURITY_NETWORK @@ -324,20 +316,16 @@ static void __unix_set_addr_hash(struct net *net, struct sock *sk, static void unix_remove_socket(struct net *net, struct sock *sk) { - spin_lock(&unix_table_locks[sk->sk_hash]); spin_lock(&net->unx.table.locks[sk->sk_hash]); __unix_remove_socket(sk); spin_unlock(&net->unx.table.locks[sk->sk_hash]); - spin_unlock(&unix_table_locks[sk->sk_hash]); } static void unix_insert_unbound_socket(struct net *net, struct sock *sk) { - spin_lock(&unix_table_locks[sk->sk_hash]); spin_lock(&net->unx.table.locks[sk->sk_hash]); __unix_insert_socket(net, sk); spin_unlock(&net->unx.table.locks[sk->sk_hash]); - spin_unlock(&unix_table_locks[sk->sk_hash]); } static struct sock *__unix_find_socket_byname(struct net *net, @@ -362,13 +350,11 @@ static inline struct sock *unix_find_socket_byname(struct net *net, { struct sock *s; - spin_lock(&unix_table_locks[hash]); spin_lock(&net->unx.table.locks[hash]); s = __unix_find_socket_byname(net, sunname, len, hash); if (s) sock_hold(s); spin_unlock(&net->unx.table.locks[hash]); - spin_unlock(&unix_table_locks[hash]); return s; } @@ -377,7 +363,6 @@ static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i) unsigned int hash = unix_bsd_hash(i); struct sock *s; - spin_lock(&unix_table_locks[hash]); spin_lock(&net->unx.table.locks[hash]); sk_for_each(s, &net->unx.table.buckets[hash]) { struct dentry *dentry = unix_sk(s)->path.dentry; @@ -385,12 +370,10 @@ static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i) if (dentry && d_backing_inode(dentry) == i) { sock_hold(s); spin_unlock(&net->unx.table.locks[hash]); - spin_unlock(&unix_table_locks[hash]); return s; } } spin_unlock(&net->unx.table.locks[hash]); - spin_unlock(&unix_table_locks[hash]); return NULL; } @@ -1551,9 +1534,9 @@ restart: * * The contents of *(otheru->addr) and otheru->path * are seen fully set up here, since we have found - * otheru in hash under unix_table_locks. Insertion - * into the hash chain we'd found it in had been done - * in an earlier critical area protected by unix_table_locks, + * otheru in hash under its lock. Insertion into the + * hash chain we'd found it in had been done in an + * earlier critical area protected by the chain's lock, * the same one where we'd set *(otheru->addr) contents, * as well as otheru->path and otheru->addr itself. * @@ -3253,7 +3236,6 @@ static struct sock *unix_get_first(struct seq_file *seq, loff_t *pos) struct sock *sk; while (bucket < UNIX_HASH_SIZE) { - spin_lock(&unix_table_locks[bucket]); spin_lock(&net->unx.table.locks[bucket]); sk = unix_from_bucket(seq, pos); @@ -3261,7 +3243,6 @@ static struct sock *unix_get_first(struct seq_file *seq, loff_t *pos) return sk; spin_unlock(&net->unx.table.locks[bucket]); - spin_unlock(&unix_table_locks[bucket]); *pos = set_bucket_offset(++bucket, 1); } @@ -3280,7 +3261,6 @@ static struct sock *unix_get_next(struct seq_file *seq, struct sock *sk, spin_unlock(&seq_file_net(seq)->unx.table.locks[bucket]); - spin_unlock(&unix_table_locks[bucket]); *pos = set_bucket_offset(++bucket, 1); @@ -3309,10 +3289,8 @@ static void unix_seq_stop(struct seq_file *seq, void *v) { struct sock *sk = v; - if (sk) { + if (sk) spin_unlock(&seq_file_net(seq)->unx.table.locks[sk->sk_hash]); - spin_unlock(&unix_table_locks[sk->sk_hash]); - } } static int unix_seq_show(struct seq_file *seq, void *v) @@ -3337,7 +3315,7 @@ static int unix_seq_show(struct seq_file *seq, void *v) (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), sock_i_ino(s)); - if (u->addr) { // under unix_table_locks here + if (u->addr) { // under a hash table lock here int i, len; seq_putc(seq, ' '); @@ -3416,7 +3394,6 @@ static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk) } spin_unlock(&seq_file_net(seq)->unx.table.locks[start_sk->sk_hash]); - spin_unlock(&unix_table_locks[start_sk->sk_hash]); return expected; } @@ -3705,13 +3682,10 @@ static void __init bpf_iter_register(void) static int __init af_unix_init(void) { - int i, rc = -1; + int rc = -1; BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb)); - for (i = 0; i < UNIX_HASH_SIZE; i++) - spin_lock_init(&unix_table_locks[i]); - rc = proto_register(&unix_dgram_proto, 1); if (rc != 0) { pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__); -- cgit