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-rw-r--r--Documentation/sysctl/net.txt10
-rw-r--r--include/linux/netdevice.h1
-rw-r--r--net/core/dev.c50
-rw-r--r--net/core/sysctl_net_core.c7
4 files changed, 49 insertions, 19 deletions
diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
index df38ef046f8d..cbd05ffc606b 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 69022d47d6f2..c1b2341897c2 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 5cbba0927a8e..988e42912e72 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 dcc7d25996ab..01eee5d984be 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),