add tcp bugfix causing high CPU load
[ bug introduced in 2.6.32-rc1 ] svn path=/dists/sid/linux-2.6/; revision=15277
This commit is contained in:
parent
301d7ad762
commit
8de617f5f7
|
@ -1,3 +1,9 @@
|
||||||
|
linux-2.6 (2.6.32-10) UNRELEASED; urgency=low
|
||||||
|
|
||||||
|
* tcp: fix ICMP-RTO war.
|
||||||
|
|
||||||
|
-- maximilian attems <maks@debian.org> Thu, 25 Feb 2010 13:07:47 +0100
|
||||||
|
|
||||||
linux-2.6 (2.6.32-9) unstable; urgency=high
|
linux-2.6 (2.6.32-9) unstable; urgency=high
|
||||||
|
|
||||||
[ Ben Hutchings ]
|
[ Ben Hutchings ]
|
||||||
|
|
|
@ -0,0 +1,51 @@
|
||||||
|
From 598856407d4e20ebb4de01a91a93d89325924d43 Mon Sep 17 00:00:00 2001
|
||||||
|
From: Damian Lukowski <damian@tvk.rwth-aachen.de>
|
||||||
|
Date: Wed, 10 Feb 2010 18:04:08 -0800
|
||||||
|
Subject: [PATCH] tcp: fix ICMP-RTO war
|
||||||
|
|
||||||
|
Make sure, that TCP has a nonzero RTT estimation after three-way
|
||||||
|
handshake. Currently, a listening TCP has a value of 0 for srtt,
|
||||||
|
rttvar and rto right after the three-way handshake is completed
|
||||||
|
with TCP timestamps disabled.
|
||||||
|
This will lead to corrupt RTO recalculation and retransmission
|
||||||
|
flood when RTO is recalculated on backoff reversion as introduced
|
||||||
|
in "Revert RTO on ICMP destination unreachable"
|
||||||
|
(f1ecd5d9e7366609d640ff4040304ea197fbc618).
|
||||||
|
This behaviour can be provoked by connecting to a server which
|
||||||
|
"responds first" (like SMTP) and rejecting every packet after
|
||||||
|
the handshake with dest-unreachable, which will lead to softirq
|
||||||
|
load on the server (up to 30% per socket in some tests).
|
||||||
|
|
||||||
|
Thanks to Ilpo Jarvinen for providing debug patches and to
|
||||||
|
Denys Fedoryshchenko for reporting and testing.
|
||||||
|
|
||||||
|
Changes since v3: Removed bad characters in patchfile.
|
||||||
|
|
||||||
|
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
|
||||||
|
Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de>
|
||||||
|
Signed-off-by: David S. Miller <davem@davemloft.net>
|
||||||
|
---
|
||||||
|
net/ipv4/tcp_input.c | 6 ++----
|
||||||
|
1 files changed, 2 insertions(+), 4 deletions(-)
|
||||||
|
|
||||||
|
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
|
||||||
|
index 28e0296..3fddc69 100644
|
||||||
|
--- a/net/ipv4/tcp_input.c
|
||||||
|
+++ b/net/ipv4/tcp_input.c
|
||||||
|
@@ -5783,11 +5783,9 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
|
||||||
|
|
||||||
|
/* tcp_ack considers this ACK as duplicate
|
||||||
|
* and does not calculate rtt.
|
||||||
|
- * Fix it at least with timestamps.
|
||||||
|
+ * Force it here.
|
||||||
|
*/
|
||||||
|
- if (tp->rx_opt.saw_tstamp &&
|
||||||
|
- tp->rx_opt.rcv_tsecr && !tp->srtt)
|
||||||
|
- tcp_ack_saw_tstamp(sk, 0);
|
||||||
|
+ tcp_ack_update_rtt(sk, 0, 0);
|
||||||
|
|
||||||
|
if (tp->rx_opt.tstamp_ok)
|
||||||
|
tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
|
||||||
|
--
|
||||||
|
1.6.6.1
|
||||||
|
|
|
@ -0,0 +1 @@
|
||||||
|
+ bugfix/all/tcp-fix-ICMP-RTO-war.patch
|
Loading…
Reference in New Issue