net: convert syn_wait_lock to a spinlock
This is a low hanging fruit, as we'll get rid of syn_wait_lock eventually.
We hold syn_wait_lock for such small sections, that it makes no sense to use
a read/write lock. A spin lock is simply faster.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 711ab143..79c0c94 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -495,7 +495,7 @@
u32 hash = inet_synq_hash(raddr, rport, lopt->hash_rnd,
lopt->nr_table_entries);
- write_lock(&icsk->icsk_accept_queue.syn_wait_lock);
+ spin_lock(&icsk->icsk_accept_queue.syn_wait_lock);
for (req = lopt->syn_table[hash]; req != NULL; req = req->dl_next) {
const struct inet_request_sock *ireq = inet_rsk(req);
@@ -508,7 +508,7 @@
break;
}
}
- write_unlock(&icsk->icsk_accept_queue.syn_wait_lock);
+ spin_unlock(&icsk->icsk_accept_queue.syn_wait_lock);
return req;
}
@@ -650,10 +650,10 @@
setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
req->rsk_hash = hash;
- write_lock(&queue->syn_wait_lock);
+ spin_lock(&queue->syn_wait_lock);
req->dl_next = lopt->syn_table[hash];
lopt->syn_table[hash] = req;
- write_unlock(&queue->syn_wait_lock);
+ spin_unlock(&queue->syn_wait_lock);
mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
}