[ovs-dev] [PATCH 5/5] dpif-netdev: Reset RSS hash when recirculating.

[Daniele Di Proietto]

Having the same RSS hash after recirculation can cause unnecessary
collisions in the exact match cache.  Setting the RSS hash to 0 forces
the datapath to compute a new value and account for the changes in the
packet or in the metadata.

Requested-by: Ethan Jackson <ethan at nicira.com>
Signed-off-by: Daniele Di Proietto <diproiettod at vmware.com>
---
 lib/dpif-netdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 20bb498..28262e6 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -3404,6 +3404,10 @@ dp_execute_cb(void *aux_, struct dp_packet **packets, int cnt,
 
             err = push_tnl_action(dp, a, packets, cnt);
             if (!err) {
+                for (i = 0; i < cnt; i++) {
+                    dp_packet_set_rss_hash(packets[i], 0);
+                }
+
                 (*depth)++;
                 dp_netdev_input(pmd, packets, cnt);
                 (*depth)--;
@@ -3433,6 +3437,7 @@ dp_execute_cb(void *aux_, struct dp_packet **packets, int cnt,
 
                     for (i = 0; i < cnt; i++) {
                         packets[i]->md.in_port.odp_port = portno;
+                        dp_packet_set_rss_hash(packets[i], 0);
                     }
 
                     (*depth)++;
@@ -3491,6 +3496,7 @@ dp_execute_cb(void *aux_, struct dp_packet **packets, int cnt,
 
             for (i = 0; i < cnt; i++) {
                 packets[i]->md.recirc_id = nl_attr_get_u32(a);
+                dp_packet_set_rss_hash(packets[i], 0);
             }
 
             (*depth)++;
-- 
2.1.4