On 04/26/2016 09:55 AM, Jason Wang wrote: > 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 <m...@redhat.com> > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > drivers/net/tun.c | 2 +- > net/core/dev.c | 1 + > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index afdf950..746877f 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -819,7 +819,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, > struct net_device *dev) > if (txq >= numqueues) > goto drop; > > - if (numqueues == 1) { > + if (numqueues == 1 && static_key_false(&rps_needed)) { > /* Select queue was not called for the skbuff, so we extract the > * RPS hash and save it into the flow_table here. > */ > diff --git a/net/core/dev.c b/net/core/dev.c > index b9bcbe7..d4ba936 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -3428,6 +3428,7 @@ u32 rps_cpu_mask __read_mostly; > EXPORT_SYMBOL(rps_cpu_mask); > > struct static_key rps_needed __read_mostly; > +EXPORT_SYMBOL(rps_needed); > > static struct rps_dev_flow * > set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
Kbuild bot reports an error when !CONFIG_RPS. Will send V2 to fix this.