diff options
| author | Jason Wang <jasowang@redhat.com> | 2016-04-26 05:13:42 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-28 22:38:54 +0200 |
| commit | 3df97ba83019d524c012fd43d3216d4cc3005955 (patch) | |
| tree | d913793fb00287a9e120f36d9a6d274a0257c2f4 | |
| parent | Merge branch 'tcp-eor' (diff) | |
| download | linux-3df97ba83019d524c012fd43d3216d4cc3005955.tar.xz linux-3df97ba83019d524c012fd43d3216d4cc3005955.zip | |
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>
| -rw-r--r-- | drivers/net/tun.c | 4 | ||||
| -rw-r--r-- | net/core/dev.c | 1 |
2 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 42992dcbdda8..425e983bab93 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -833,7 +833,8 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) if (txq >= numqueues) goto drop; - if (numqueues == 1) { +#ifdef CONFIG_RPS + 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. */ @@ -848,6 +849,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) tun_flow_save_rps_rxhash(e, rxhash); } } +#endif tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len); diff --git a/net/core/dev.c b/net/core/dev.c index e96a3bc2c634..c2f3d5dbde56 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3469,6 +3469,7 @@ 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, |