From e36fa2f7e92f25aab2e3d787dcfe3590817f19d3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 19 Apr 2010 21:17:14 +0000 Subject: [PATCH] rps: cleanups struct softnet_data holds many queues, so consistent use "sd" name instead of "queue" is better. Adds a rps_ipi_queued() helper to cleanup enqueue_to_backlog() Adds a _and_irq_disable suffix to net_rps_action() name, as David suggested. incr_input_queue_head() becomes input_queue_head_incr() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 +- net/core/dev.c | 149 ++++++++++++++++++++------------------ 2 files changed, 82 insertions(+), 71 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 83ab3da149ad..3c5ed5f5274e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1401,10 +1401,10 @@ struct softnet_data { struct napi_struct backlog; }; -static inline void incr_input_queue_head(struct softnet_data *queue) +static inline void input_queue_head_incr(struct softnet_data *sd) { #ifdef CONFIG_RPS - queue->input_queue_head++; + sd->input_queue_head++; #endif } diff --git a/net/core/dev.c b/net/core/dev.c index 05a2b294906b..7f5755b0a57c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -208,17 +208,17 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex) return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)]; } -static inline void rps_lock(struct softnet_data *queue) +static inline void rps_lock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_lock(&queue->input_pkt_queue.lock); + spin_lock(&sd->input_pkt_queue.lock); #endif } -static inline void rps_unlock(struct softnet_data *queue) +static inline void rps_unlock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_unlock(&queue->input_pkt_queue.lock); + spin_unlock(&sd->input_pkt_queue.lock); #endif } @@ -2346,14 +2346,37 @@ done: } /* Called from hardirq (IPI) context */ -static void trigger_softirq(void *data) +static void rps_trigger_softirq(void *data) { - struct softnet_data *queue = data; - __napi_schedule(&queue->backlog); + struct softnet_data *sd = data; + + __napi_schedule(&sd->backlog); __get_cpu_var(netdev_rx_stat).received_rps++; } + #endif /* CONFIG_RPS */ +/* + * Check if this softnet_data structure is another cpu one + * If yes, queue it to our IPI list and return 1 + * If no, return 0 + */ +static int rps_ipi_queued(struct softnet_data *sd) +{ +#ifdef CONFIG_RPS + struct softnet_data *mysd = &__get_cpu_var(softnet_data); + + if (sd != mysd) { + sd->rps_ipi_next = mysd->rps_ipi_list; + mysd->rps_ipi_list = sd; + + __raise_softirq_irqoff(NET_RX_SOFTIRQ); + return 1; + } +#endif /* CONFIG_RPS */ + return 0; +} + /* * enqueue_to_backlog is called to queue an skb to a per CPU backlog * queue (may be a remote CPU queue). @@ -2361,48 +2384,36 @@ static void trigger_softirq(void *data) static int enqueue_to_backlog(struct sk_buff *skb, int cpu, unsigned int *qtail) { - struct softnet_data *queue; + struct softnet_data *sd; unsigned long flags; - queue = &per_cpu(softnet_data, cpu); + sd = &per_cpu(softnet_data, cpu); local_irq_save(flags); __get_cpu_var(netdev_rx_stat).total++; - rps_lock(queue); - if (queue->input_pkt_queue.qlen <= netdev_max_backlog) { - if (queue->input_pkt_queue.qlen) { + rps_lock(sd); + if (sd->input_pkt_queue.qlen <= netdev_max_backlog) { + if (sd->input_pkt_queue.qlen) { enqueue: - __skb_queue_tail(&queue->input_pkt_queue, skb); + __skb_queue_tail(&sd->input_pkt_queue, skb); #ifdef CONFIG_RPS - *qtail = queue->input_queue_head + - queue->input_pkt_queue.qlen; + *qtail = sd->input_queue_head + sd->input_pkt_queue.qlen; #endif - rps_unlock(queue); + rps_unlock(sd); local_irq_restore(flags); return NET_RX_SUCCESS; } /* Schedule NAPI for backlog device */ - if (napi_schedule_prep(&queue->backlog)) { -#ifdef CONFIG_RPS - if (cpu != smp_processor_id()) { - struct softnet_data *myqueue; - - myqueue = &__get_cpu_var(softnet_data); - queue->rps_ipi_next = myqueue->rps_ipi_list; - myqueue->rps_ipi_list = queue; - - __raise_softirq_irqoff(NET_RX_SOFTIRQ); - goto enqueue; - } -#endif - __napi_schedule(&queue->backlog); + if (napi_schedule_prep(&sd->backlog)) { + if (!rps_ipi_queued(sd)) + __napi_schedule(&sd->backlog); } goto enqueue; } - rps_unlock(queue); + rps_unlock(sd); __get_cpu_var(netdev_rx_stat).dropped++; local_irq_restore(flags); @@ -2903,17 +2914,17 @@ EXPORT_SYMBOL(netif_receive_skb); static void flush_backlog(void *arg) { struct net_device *dev = arg; - struct softnet_data *queue = &__get_cpu_var(softnet_data); + struct softnet_data *sd = &__get_cpu_var(softnet_data); struct sk_buff *skb, *tmp; - rps_lock(queue); - skb_queue_walk_safe(&queue->input_pkt_queue, skb, tmp) + rps_lock(sd); + skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) if (skb->dev == dev) { - __skb_unlink(skb, &queue->input_pkt_queue); + __skb_unlink(skb, &sd->input_pkt_queue); kfree_skb(skb); - incr_input_queue_head(queue); + input_queue_head_incr(sd); } - rps_unlock(queue); + rps_unlock(sd); } static int napi_gro_complete(struct sk_buff *skb) @@ -3219,23 +3230,23 @@ EXPORT_SYMBOL(napi_gro_frags); static int process_backlog(struct napi_struct *napi, int quota) { int work = 0; - struct softnet_data *queue = &__get_cpu_var(softnet_data); + struct softnet_data *sd = &__get_cpu_var(softnet_data); napi->weight = weight_p; do { struct sk_buff *skb; local_irq_disable(); - rps_lock(queue); - skb = __skb_dequeue(&queue->input_pkt_queue); + rps_lock(sd); + skb = __skb_dequeue(&sd->input_pkt_queue); if (!skb) { __napi_complete(napi); - rps_unlock(queue); + rps_unlock(sd); local_irq_enable(); break; } - incr_input_queue_head(queue); - rps_unlock(queue); + input_queue_head_incr(sd); + rps_unlock(sd); local_irq_enable(); __netif_receive_skb(skb); @@ -3331,24 +3342,25 @@ EXPORT_SYMBOL(netif_napi_del); * net_rps_action sends any pending IPI's for rps. * Note: called with local irq disabled, but exits with local irq enabled. */ -static void net_rps_action(void) +static void net_rps_action_and_irq_disable(void) { #ifdef CONFIG_RPS - struct softnet_data *locqueue = &__get_cpu_var(softnet_data); - struct softnet_data *remqueue = locqueue->rps_ipi_list; + struct softnet_data *sd = &__get_cpu_var(softnet_data); + struct softnet_data *remsd = sd->rps_ipi_list; - if (remqueue) { - locqueue->rps_ipi_list = NULL; + if (remsd) { + sd->rps_ipi_list = NULL; local_irq_enable(); /* Send pending IPI's to kick RPS processing on remote cpus. */ - while (remqueue) { - struct softnet_data *next = remqueue->rps_ipi_next; - if (cpu_online(remqueue->cpu)) - __smp_call_function_single(remqueue->cpu, - &remqueue->csd, 0); - remqueue = next; + while (remsd) { + struct softnet_data *next = remsd->rps_ipi_next; + + if (cpu_online(remsd->cpu)) + __smp_call_function_single(remsd->cpu, + &remsd->csd, 0); + remsd = next; } } else #endif @@ -3423,7 +3435,7 @@ static void net_rx_action(struct softirq_action *h) netpoll_poll_unlock(have); } out: - net_rps_action(); + net_rps_action_and_irq_disable(); #ifdef CONFIG_NET_DMA /* @@ -5595,7 +5607,7 @@ static int dev_cpu_callback(struct notifier_block *nfb, /* Process offline CPU's input_pkt_queue */ while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx(skb); - incr_input_queue_head(oldsd); + input_queue_head_incr(oldsd); } return NOTIFY_OK; @@ -5812,24 +5824,23 @@ static int __init net_dev_init(void) */ for_each_possible_cpu(i) { - struct softnet_data *queue; + struct softnet_data *sd = &per_cpu(softnet_data, i); - queue = &per_cpu(softnet_data, i); - skb_queue_head_init(&queue->input_pkt_queue); - queue->completion_queue = NULL; - INIT_LIST_HEAD(&queue->poll_list); + skb_queue_head_init(&sd->input_pkt_queue); + sd->completion_queue = NULL; + INIT_LIST_HEAD(&sd->poll_list); #ifdef CONFIG_RPS - queue->csd.func = trigger_softirq; - queue->csd.info = queue; - queue->csd.flags = 0; - queue->cpu = i; + sd->csd.func = rps_trigger_softirq; + sd->csd.info = sd; + sd->csd.flags = 0; + sd->cpu = i; #endif - queue->backlog.poll = process_backlog; - queue->backlog.weight = weight_p; - queue->backlog.gro_list = NULL; - queue->backlog.gro_count = 0; + sd->backlog.poll = process_backlog; + sd->backlog.weight = weight_p; + sd->backlog.gro_list = NULL; + sd->backlog.gro_count = 0; } dev_boot_phase = 0; -- 2.20.1