net-rps: Fix brokeness causing OOO packets

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>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index bda6d004f9f0..c0946cb2b354 100644
--- 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;