diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt index f0480f7ea740..b80fbd4e5575 100644 --- a/Documentation/sysctl/net.txt +++ b/Documentation/sysctl/net.txt @@ -61,6 +61,27 @@ The maximum number of packets that kernel can handle on a NAPI interrupt, it's a Per-CPU variable. Default: 64 +dev_weight_rx_bias +-------------- + +RPS (e.g. RFS, aRFS) processing is competing with the registered NAPI poll function +of the driver for the per softirq cycle netdev_budget. This parameter influences +the proportion of the configured netdev_budget that is spent on RPS based packet +processing during RX softirq cycles. It is further meant for making current +dev_weight adaptable for asymmetric CPU needs on RX/TX side of the network stack. +(see dev_weight_tx_bias) It is effective on a per CPU basis. Determination is based +on dev_weight and is calculated multiplicative (dev_weight * dev_weight_rx_bias). +Default: 1 + +dev_weight_tx_bias +-------------- + +Scales the maximum number of packets that can be processed during a TX softirq cycle. +Effective on a per CPU basis. Allows scaling of current dev_weight for asymmetric +net stack processing needs. Be careful to avoid making TX softirq processing a CPU hog. +Calculation is based on dev_weight (dev_weight * dev_weight_tx_bias). +Default: 1 + default_qdisc -------------- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 994f7423a74b..ecd78b3c9aba 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3795,6 +3795,10 @@ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, extern int netdev_max_backlog; extern int netdev_tstamp_prequeue; extern int weight_p; +extern int dev_weight_rx_bias; +extern int dev_weight_tx_bias; +extern int dev_rx_weight; +extern int dev_tx_weight; bool netdev_has_upper_dev(struct net_device *dev, struct net_device *upper_dev); struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev, diff --git a/net/core/dev.c b/net/core/dev.c index 8db5a0b4b520..56818f7eab2b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3427,7 +3427,11 @@ EXPORT_SYMBOL(netdev_max_backlog); int netdev_tstamp_prequeue __read_mostly = 1; int netdev_budget __read_mostly = 300; -int weight_p __read_mostly = 64; /* old backlog weight */ +int weight_p __read_mostly = 64; /* old backlog weight */ +int dev_weight_rx_bias __read_mostly = 1; /* bias for backlog weight */ +int dev_weight_tx_bias __read_mostly = 1; /* bias for output_queue quota */ +int dev_rx_weight __read_mostly = 64; +int dev_tx_weight __read_mostly = 64; /* Called with irq disabled */ static inline void ____napi_schedule(struct softnet_data *sd, @@ -4833,7 +4837,7 @@ static int process_backlog(struct napi_struct *napi, int quota) net_rps_action_and_irq_enable(sd); } - napi->weight = weight_p; + napi->weight = dev_rx_weight; while (again) { struct sk_buff *skb; diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 2a46e4009f62..eaa72eb0399c 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -222,6 +222,21 @@ static int set_default_qdisc(struct ctl_table *table, int write, } #endif +static int proc_do_dev_weight(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int ret; + + ret = proc_dointvec(table, write, buffer, lenp, ppos); + if (ret != 0) + return ret; + + dev_rx_weight = weight_p * dev_weight_rx_bias; + dev_tx_weight = weight_p * dev_weight_tx_bias; + + return ret; +} + static int proc_do_rss_key(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { @@ -273,7 +288,21 @@ static struct ctl_table net_core_table[] = { .data = &weight_p, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_do_dev_weight, + }, + { + .procname = "dev_weight_rx_bias", + .data = &dev_weight_rx_bias, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_do_dev_weight, + }, + { + .procname = "dev_weight_tx_bias", + .data = &dev_weight_tx_bias, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_do_dev_weight, }, { .procname = "netdev_max_backlog", diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 6eb9c8e88519..b052b27a984e 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -247,7 +247,7 @@ static inline int qdisc_restart(struct Qdisc *q, int *packets) void __qdisc_run(struct Qdisc *q) { - int quota = weight_p; + int quota = dev_tx_weight; int packets; while (qdisc_restart(q, &packets)) {