From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 17 Aug 2016 08:04:03 +0000 (+0200)
Subject: 3.14-stable patches
X-Git-Tag: v3.14.77~44
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e09bea58ec0552dbbf71fb22bf7a46da9a288fc8;p=thirdparty%2Fkernel%2Fstable-queue.git

3.14-stable patches

added patches:
	tcp_acks_speedup.patch
---

diff --git a/queue-3.14/series b/queue-3.14/series
new file mode 100644
index 00000000000..e8b07d1bbaa
--- /dev/null
+++ b/queue-3.14/series
@@ -0,0 +1 @@
+tcp_acks_speedup.patch
diff --git a/queue-3.14/tcp_acks_speedup.patch b/queue-3.14/tcp_acks_speedup.patch
new file mode 100644
index 00000000000..0d4c0f1f8fb
--- /dev/null
+++ b/queue-3.14/tcp_acks_speedup.patch
@@ -0,0 +1,48 @@
+From foo@baz Wed Aug 17 10:00:14 CEST 2016
+Date: Wed, 17 Aug 2016 10:00:14 +0200
+To: Greg KH <gregkh@linuxfoundation.org>
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Subject: tcp: make challenge acks faster
+
+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);
+ 	}