diff options
| -rw-r--r-- | include/net/rps.h | 7 | ||||
| -rw-r--r-- | net/core/dev.c | 64 | ||||
| -rw-r--r-- | net/core/net-sysfs.c | 4 |
3 files changed, 65 insertions, 10 deletions
diff --git a/include/net/rps.h b/include/net/rps.h index d8ab3a08bcc4..9917dce42ca4 100644 --- a/include/net/rps.h +++ b/include/net/rps.h @@ -25,13 +25,16 @@ struct rps_map { /* * The rps_dev_flow structure contains the mapping of a flow to a CPU, the - * tail pointer for that CPU's input queue at the time of last enqueue, and - * a hardware filter index. + * tail pointer for that CPU's input queue at the time of last enqueue, a + * hardware filter index, and the hash of the flow if aRFS is enabled. */ struct rps_dev_flow { u16 cpu; u16 filter; unsigned int last_qtail; +#ifdef CONFIG_RFS_ACCEL + u32 hash; +#endif }; #define RPS_NO_FILTER 0xffff diff --git a/net/core/dev.c b/net/core/dev.c index 93a25d87b86b..fbf0894c55d0 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4849,6 +4849,36 @@ static u32 rfs_slot(u32 hash, const struct rps_dev_flow_table *flow_table) return hash_32(hash, flow_table->log); } +#ifdef CONFIG_RFS_ACCEL +/** + * rps_flow_is_active - check whether the flow is recently active. + * @rflow: Specific flow to check activity. + * @flow_table: per-queue flowtable that @rflow belongs to. + * @cpu: CPU saved in @rflow. + * + * If the CPU has processed many packets since the flow's last activity + * (beyond 10 times the table size), the flow is considered stale. + * + * Return: true if flow was recently active. + */ +static bool rps_flow_is_active(struct rps_dev_flow *rflow, + struct rps_dev_flow_table *flow_table, + unsigned int cpu) +{ + unsigned int flow_last_active; + unsigned int sd_input_head; + + if (cpu >= nr_cpu_ids) + return false; + + sd_input_head = READ_ONCE(per_cpu(softnet_data, cpu).input_queue_head); + flow_last_active = READ_ONCE(rflow->last_qtail); + + return (int)(sd_input_head - flow_last_active) < + (int)(10 << flow_table->log); +} +#endif + static struct rps_dev_flow * set_rps_cpu(struct net_device *dev, struct sk_buff *skb, struct rps_dev_flow *rflow, u16 next_cpu) @@ -4859,8 +4889,11 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb, struct netdev_rx_queue *rxqueue; struct rps_dev_flow_table *flow_table; struct rps_dev_flow *old_rflow; + struct rps_dev_flow *tmp_rflow; + unsigned int tmp_cpu; u16 rxq_index; u32 flow_id; + u32 hash; int rc; /* Should we steer this flow to a different hardware queue? */ @@ -4875,14 +4908,32 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb, flow_table = rcu_dereference(rxqueue->rps_flow_table); if (!flow_table) goto out; - flow_id = rfs_slot(skb_get_hash(skb), flow_table); + + hash = skb_get_hash(skb); + flow_id = rfs_slot(hash, flow_table); + + tmp_rflow = &flow_table->flows[flow_id]; + tmp_cpu = READ_ONCE(tmp_rflow->cpu); + + if (READ_ONCE(tmp_rflow->filter) != RPS_NO_FILTER) { + if (rps_flow_is_active(tmp_rflow, flow_table, + tmp_cpu)) { + if (hash != READ_ONCE(tmp_rflow->hash) || + next_cpu == tmp_cpu) + goto out; + } + } + rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb, rxq_index, flow_id); if (rc < 0) goto out; + old_rflow = rflow; - rflow = &flow_table->flows[flow_id]; + rflow = tmp_rflow; WRITE_ONCE(rflow->filter, rc); + WRITE_ONCE(rflow->hash, hash); + if (old_rflow->filter == rc) WRITE_ONCE(old_rflow->filter, RPS_NO_FILTER); out: @@ -5017,17 +5068,16 @@ bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, struct rps_dev_flow_table *flow_table; struct rps_dev_flow *rflow; bool expire = true; - unsigned int cpu; rcu_read_lock(); flow_table = rcu_dereference(rxqueue->rps_flow_table); if (flow_table && flow_id < (1UL << flow_table->log)) { + unsigned int cpu; + rflow = &flow_table->flows[flow_id]; cpu = READ_ONCE(rflow->cpu); - if (READ_ONCE(rflow->filter) == filter_id && cpu < nr_cpu_ids && - ((int)(READ_ONCE(per_cpu(softnet_data, cpu).input_queue_head) - - READ_ONCE(rflow->last_qtail)) < - (int)(10 << flow_table->log))) + if (READ_ONCE(rflow->filter) == filter_id && + rps_flow_is_active(rflow, flow_table, cpu)) expire = false; } rcu_read_unlock(); diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index c28cd6665444..5ea9f64adce3 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1120,8 +1120,10 @@ static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue, return -ENOMEM; table->log = ilog2(mask) + 1; - for (count = 0; count <= mask; count++) + for (count = 0; count <= mask; count++) { table->flows[count].cpu = RPS_NO_CPU; + table->flows[count].filter = RPS_NO_FILTER; + } } else { table = NULL; } |