From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:55958 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014AbcHQIDz (ORCPT ); Wed, 17 Aug 2016 04:03:55 -0400 Subject: Patch "tcp: make challenge acks faster" has been added to the 3.14-stable tree To: gregkh@linuxfoundation.org, ciwillia@brocade.com, davem@davemloft.net, edumazet@google.com, ncardwell@google.com, torvalds@linux-foundation.org, w@1wt.eu, ycao009@ucr.edu, ycheng@google.com Cc: , From: Date: Wed, 17 Aug 2016 10:04:03 +0200 Message-ID: <147142104322328@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tcp: make challenge acks faster to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp_acks_speedup.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Wed Aug 17 10:00:14 CEST 2016 Date: Wed, 17 Aug 2016 10:00:14 +0200 To: Greg KH From: Greg Kroah-Hartman Subject: tcp: make challenge acks faster From: Greg Kroah-Hartman 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 Cc: Eric Dumazet Cc: Linus Torvalds Cc: Yuchung Cheng Cc: Neal Cardwell Cc: Neal Cardwell Cc: Yuchung Cheng Cc: David S. Miller Cc: Chas Williams Cc: Willy Tarreau Signed-off-by: Greg Kroah-Hartman --- 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); } Patches currently in stable-queue which might be from gregkh@linuxfoundation.org are queue-3.14/tcp_acks_speedup.patch