Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 01/46] tcp: make challenge acks faster | Date | Thu, 18 Aug 2016 15:54:23 +0200 |
| |
3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When backporting upstream commit 75ff39ccc1bd ("tcp: make challenge acks less predictable") I negelected to use the correct ACCESS* type macros. This fixes that up to hopefully speed things up a bit more.
Thanks to Chas Wiliams for the 3.10 backport which reminded me of this.
Cc: Yue Cao <ycao009@ucr.edu> Cc: Eric Dumazet <edumazet@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chas Williams <ciwillia@brocade.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/ipv4/tcp_input.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3299,12 +3299,12 @@ static void tcp_send_challenge_ack(struc u32 half = (sysctl_tcp_challenge_ack_limit + 1) >> 1; challenge_timestamp = now; - challenge_count = half + + ACCESS_ONCE(challenge_count) = half + prandom_u32_max(sysctl_tcp_challenge_ack_limit); } - count = challenge_count; + count = ACCESS_ONCE(challenge_count); if (count > 0) { - challenge_count = count - 1; + ACCESS_ONCE(challenge_count) = count - 1; NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPCHALLENGEACK); tcp_send_ack(sk); }
| |