path: root/net/ipv4/tcp_fastopen.c
diff options
authorEric Dumazet <edumazet@google.com>2015-09-29 07:42:52 -0700
committerDavid S. Miller <davem@davemloft.net>2015-09-29 16:53:10 -0700
commit0536fcc039a8926ec12ec587f41a83f7acafeb82 (patch)
tree335da15ef581d750ada2ba11e6ca6900ba82ae86 /net/ipv4/tcp_fastopen.c
parenttcp: constify tcp_syn_flood_action() socket argument (diff)
tcp: prepare fastopen code for upcoming listener changes
While auditing TCP stack for upcoming 'lockless' listener changes, I found I had to change fastopen_init_queue() to properly init the object before publishing it. Otherwise an other cpu could try to lock the spinlock before it gets properly initialized. Instead of adding appropriate barriers, just remove dynamic memory allocations : - Structure is 28 bytes on 64bit arches. Using additional 8 bytes for holding a pointer seems overkill. - Two listeners can share same cache line and performance would suffer. If we really want to save few bytes, we would instead dynamically allocate whole struct request_sock_queue in the future. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
1 files changed, 5 insertions, 5 deletions
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index db43c6286cf7..f69f436fcbcc 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -142,9 +142,9 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
if (!child)
return NULL;
- spin_lock(&queue->fastopenq->lock);
- queue->fastopenq->qlen++;
- spin_unlock(&queue->fastopenq->lock);
+ spin_lock(&queue->fastopenq.lock);
+ queue->fastopenq.qlen++;
+ spin_unlock(&queue->fastopenq.lock);
/* Initialize the child socket. Have to fix some values to take
* into account the child is a Fast Open socket and is created
@@ -237,8 +237,8 @@ static bool tcp_fastopen_queue_check(struct sock *sk)
* between qlen overflow causing Fast Open to be disabled
* temporarily vs a server not supporting Fast Open at all.
- fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq;
- if (!fastopenq || fastopenq->max_qlen == 0)
+ fastopenq = &inet_csk(sk)->icsk_accept_queue.fastopenq;
+ if (fastopenq->max_qlen == 0)
return false;
if (fastopenq->qlen >= fastopenq->max_qlen) {