Patch "tcp: convert cached rtt from usec to jiffies when feeding initial rto" has been added to the 4.4-stable tree

Patch "tcp: convert cached rtt from usec to jiffies when feeding initial rto" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tcp: convert cached rtt from usec to jiffies when feeding initial rto

to the 4.4-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-convert-cached-rtt-from-usec-to-jiffies-when-feeding-initial-rto.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Apr 16 10:02:52 PDT 2016
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Date: Sun, 21 Feb 2016 10:12:39 +0300
Subject: tcp: convert cached rtt from usec to jiffies when feeding initial rto

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

[ Upstream commit 9bdfb3b79e61c60e1a3e2dc05ad164528afa6b8a ]

Currently it's converted into msecs, thus HZ=1000 intact.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 740b0f1841f6 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/tcp_metrics.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -550,7 +550,7 @@ reset:
 	 */
 	if (crtt > tp->srtt_us) {
 		/* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
-		crtt /= 8 * USEC_PER_MSEC;
+		crtt /= 8 * USEC_PER_SEC / HZ;
 		inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
 	} else if (tp->srtt_us == 0) {
 		/* RFC6298: 5.7 We've failed to get a valid RTT sample from


Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are

queue-4.4/tcp-convert-cached-rtt-from-usec-to-jiffies-when-feeding-initial-rto.patch