net-rps: Fix brokeness causing OOO packets

In commit 8d061a6de72c704d 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>

diff --git a/net/core/dev.c b/net/core/dev.c
index bda6d004f9f0940df66a00170e8a0d6b52dd540a..c0946cb2b3547f4fdea0fa56b8f7e17c71a75012 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2818,8 +2818,10 @@ 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;