[3.5.y.z,extended,stable] Patch "net-rps: Fix brokeness causing OOO packets" has been added to staging queue

Message ID 1355289137-32019-1-git-send-email-herton.krzesinski@canonical.com
State New
Headers show

Commit Message

Herton Ronaldo Krzesinski Dec. 12, 2012, 5:12 a.m.
This is a note to let you know that I have just added a patch titled

    net-rps: Fix brokeness causing OOO packets

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



From 4f41574b83049c523faa5468bb65a9f490394779 Mon Sep 17 00:00:00 2001
From: Tom Herbert <therbert@google.com>
Date: Fri, 16 Nov 2012 09:04:15 +0000
Subject: [PATCH] net-rps: Fix brokeness causing OOO packets

commit baefa31db2f2b13a05d1b81bdf2d20d487f58b0a upstream.

In commit c445477d74ab3779 which adds aRFS to the kernel, the CPU
selected for RFS is not set correctly when CPU is changing.
This is causing OOO packets and probably other issues.

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
 net/core/dev.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)



diff --git a/net/core/dev.c b/net/core/dev.c
index 75845ba..3ad746b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2761,8 +2761,10 @@  static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
 		if (unlikely(tcpu != next_cpu) &&
 		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
-		      rflow->last_qtail)) >= 0))
+		      rflow->last_qtail)) >= 0)) {
+			tcpu = next_cpu;
 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
+		}

 		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
 			*rflowp = rflow;