diff options
| -rw-r--r-- | Documentation/sysctl/net.txt | 10 | ||||
| -rw-r--r-- | include/linux/netdevice.h | 1 | ||||
| -rw-r--r-- | net/core/dev.c | 50 | ||||
| -rw-r--r-- | net/core/sysctl_net_core.c | 7 |
4 files changed, 49 insertions, 19 deletions
diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt index df38ef046f8..cbd05ffc606 100644 --- a/Documentation/sysctl/net.txt +++ b/Documentation/sysctl/net.txt @@ -84,6 +84,16 @@ netdev_max_backlog Maximum number of packets, queued on the INPUT side, when the interface receives packets faster than kernel can process them. +netdev_tstamp_prequeue +---------------------- + +If set to 0, RX packet timestamps can be sampled after RPS processing, when +the target CPU processes packets. It might give some delay on timestamps, but +permit to distribute the load on several cpus. + +If set to 1 (default), timestamps are sampled as soon as possible, before +queueing. + optmem_max ---------- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 69022d47d6f..c1b2341897c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2100,6 +2100,7 @@ extern const struct net_device_stats *dev_get_stats(struct net_device *dev); extern void dev_txq_stats_fold(const struct net_device *dev, struct net_device_stats *stats); extern int netdev_max_backlog; +extern int netdev_tstamp_prequeue; extern int weight_p; extern int netdev_set_master(struct net_device *dev, struct net_device *master); extern int skb_checksum_help(struct sk_buff *skb); diff --git a/net/core/dev.c b/net/core/dev.c index 5cbba0927a8..988e42912e7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1454,7 +1454,7 @@ void net_disable_timestamp(void) } EXPORT_SYMBOL(net_disable_timestamp); -static inline void net_timestamp(struct sk_buff *skb) +static inline void net_timestamp_set(struct sk_buff *skb) { if (atomic_read(&netstamp_needed)) __net_timestamp(skb); @@ -1462,6 +1462,12 @@ static inline void net_timestamp(struct sk_buff *skb) skb->tstamp.tv64 = 0; } +static inline void net_timestamp_check(struct sk_buff *skb) +{ + if (!skb->tstamp.tv64 && atomic_read(&netstamp_needed)) + __net_timestamp(skb); +} + /** * dev_forward_skb - loopback an skb to another netif * @@ -1508,9 +1514,9 @@ static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev) #ifdef CONFIG_NET_CLS_ACT if (!(skb->tstamp.tv64 && (G_TC_FROM(skb->tc_verd) & AT_INGRESS))) - net_timestamp(skb); + net_timestamp_set(skb); #else - net_timestamp(skb); + net_timestamp_set(skb); #endif rcu_read_lock(); @@ -2201,6 +2207,7 @@ EXPORT_SYMBOL(dev_queue_xmit); =======================================================================*/ int netdev_max_backlog __read_mostly = 1000; +int netdev_tstamp_prequeue __read_mostly = 1; int netdev_budget __read_mostly = 300; int weight_p __read_mostly = 64; /* old backlog weight */ @@ -2465,8 +2472,8 @@ int netif_rx(struct sk_buff *skb) if (netpoll_rx(skb)) return NET_RX_DROP; - if (!skb->tstamp.tv64) - net_timestamp(skb); + if (netdev_tstamp_prequeue) + net_timestamp_check(skb); #ifdef CONFIG_RPS { @@ -2791,8 +2798,8 @@ static int __netif_receive_skb(struct sk_buff *skb) int ret = NET_RX_DROP; __be16 type; - if (!skb->tstamp.tv64) - net_timestamp(skb); + if (!netdev_tstamp_prequeue) + net_timestamp_check(skb); if (vlan_tx_tag_present(skb) && vlan_hwaccel_do_receive(skb)) return NET_RX_SUCCESS; @@ -2910,23 +2917,28 @@ out: */ int netif_receive_skb(struct sk_buff *skb) { + if (netdev_tstamp_prequeue) + net_timestamp_check(skb); + #ifdef CONFIG_RPS - struct rps_dev_flow voidflow, *rflow = &voidflow; - int cpu, ret; + { + struct rps_dev_flow voidflow, *rflow = &voidflow; + int cpu, ret; - rcu_read_lock(); + rcu_read_lock(); + + cpu = get_rps_cpu(skb->dev, skb, &rflow); - cpu = get_rps_cpu(skb->dev, skb, &rflow); + if (cpu >= 0) { + ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); + rcu_read_unlock(); + } else { + rcu_read_unlock(); + ret = __netif_receive_skb(skb); + } - if (cpu >= 0) { - ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); - rcu_read_unlock(); - } else { - rcu_read_unlock(); - ret = __netif_receive_skb(skb); + return ret; } - - return ret; #else return __netif_receive_skb(skb); #endif diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index dcc7d25996a..01eee5d984b 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -122,6 +122,13 @@ static struct ctl_table net_core_table[] = { .proc_handler = proc_dointvec }, { + .procname = "netdev_tstamp_prequeue", + .data = &netdev_tstamp_prequeue, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { .procname = "message_cost", .data = &net_ratelimit_state.interval, .maxlen = sizeof(int), |