tuntap: calculate rps hash only when needed
authorJason Wang <jasowang@redhat.com>
Tue, 26 Apr 2016 03:13:42 +0000 (23:13 -0400)
committerDavid S. Miller <davem@davemloft.net>
Thu, 28 Apr 2016 20:38:54 +0000 (16:38 -0400)
commit3df97ba83019d524c012fd43d3216d4cc3005955
treed913793fb00287a9e120f36d9a6d274a0257c2f4
parentf345c9a5726d10cc3613d17ae75dcb1ab0986ba1
tuntap: calculate rps hash only when needed

There's no need to calculate rps hash if it was not enabled. So this
patch export rps_needed and check it before trying to get rps
hash. Tests (using pktgen to inject packets to guest) shows this can
improve pps about 13% (when rps is disabled).

Before:
~1150000 pps
After:
~1300000 pps

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
----
Changes from V1:
- Fix build when CONFIG_RPS is not set
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/tun.c
net/core/dev.c