From b282705336e03fc7b9377a278939594870a40f96 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 22 Mar 2015 10:22:21 -0700 Subject: 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 Signed-off-by: David S. Miller --- include/net/request_sock.h | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'include/net/request_sock.h') diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 8603c350fad0..fe41f3ceb008 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -173,11 +173,6 @@ struct fastopen_queue { * %syn_wait_lock is necessary only to avoid proc interface having to grab the main * lock sock while browsing the listening hash (otherwise it's deadlock prone). * - * This lock is acquired in read mode only from listening_get_next() seq_file - * op and it's acquired in write mode _only_ from code that is actively - * changing rskq_accept_head. All readers that are holding the master sock lock - * don't need to grab this lock in read mode too as rskq_accept_head. writes - * are always protected from the main sock lock. */ struct request_sock_queue { struct request_sock *rskq_accept_head; @@ -192,7 +187,7 @@ struct request_sock_queue { */ /* temporary alignment, our goal is to get rid of this lock */ - rwlock_t syn_wait_lock ____cacheline_aligned_in_smp; + spinlock_t syn_wait_lock ____cacheline_aligned_in_smp; }; int reqsk_queue_alloc(struct request_sock_queue *queue, @@ -223,14 +218,14 @@ static inline void reqsk_queue_unlink(struct request_sock_queue *queue, struct listen_sock *lopt = queue->listen_opt; struct request_sock **prev; - write_lock(&queue->syn_wait_lock); + spin_lock(&queue->syn_wait_lock); prev = &lopt->syn_table[req->rsk_hash]; while (*prev != req) prev = &(*prev)->dl_next; *prev = req->dl_next; - write_unlock(&queue->syn_wait_lock); + spin_unlock(&queue->syn_wait_lock); if (del_timer(&req->rsk_timer)) reqsk_put(req); } -- cgit v1.2.3