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| author | Eric Dumazet <edumazet@google.com> | 2015-03-22 18:22:18 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-23 21:52:25 +0100 |
| commit | 2b41fab70fc001d2acd89c0477d32feb8265bb32 (patch) | |
| tree | 1597c834b5bc63933f5d3d1d62612319280e3fd0 /net/ipv4/inet_connection_sock.c | |
| parent | Merge branch 'gigaset_modem_response' (diff) | |
| download | linux-2b41fab70fc001d2acd89c0477d32feb8265bb32.tar.xz linux-2b41fab70fc001d2acd89c0477d32feb8265bb32.zip | |
inet: cache listen_sock_qlen() and read rskq_defer_accept once
Cache listen_sock_qlen() to limit false sharing, and read
rskq_defer_accept once as it might change under us.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/inet_connection_sock.c')
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 844808d9337b..7d011e825c48 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -571,8 +571,9 @@ static void reqsk_timer_handler(unsigned long data) struct inet_connection_sock *icsk = inet_csk(sk_listener); struct request_sock_queue *queue = &icsk->icsk_accept_queue; struct listen_sock *lopt = queue->listen_opt; - int expire = 0, resend = 0; + int qlen, expire = 0, resend = 0; int max_retries, thresh; + u8 defer_accept; if (sk_listener->sk_state != TCP_LISTEN || !lopt) { reqsk_put(req); @@ -598,19 +599,21 @@ static void reqsk_timer_handler(unsigned long data) * embrions; and abort old ones without pity, if old * ones are about to clog our table. */ - if (listen_sock_qlen(lopt) >> (lopt->max_qlen_log - 1)) { + qlen = listen_sock_qlen(lopt); + if (qlen >> (lopt->max_qlen_log - 1)) { int young = listen_sock_young(lopt) << 1; while (thresh > 2) { - if (listen_sock_qlen(lopt) < young) + if (qlen < young) break; thresh--; young <<= 1; } } - if (queue->rskq_defer_accept) - max_retries = queue->rskq_defer_accept; - syn_ack_recalc(req, thresh, max_retries, queue->rskq_defer_accept, + defer_accept = READ_ONCE(queue->rskq_defer_accept); + if (defer_accept) + max_retries = defer_accept; + syn_ack_recalc(req, thresh, max_retries, defer_accept, &expire, &resend); req->rsk_ops->syn_ack_timeout(sk_listener, req); if (!expire && |