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rps: cleanups

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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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-04-19 21:17:14 +00:00 • committed by David S. Miller
commit e36fa2f7e9
2 changed files with 82 additions and 71 deletions
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4
include/linux/netdevice.h
View file

@ -1401,10 +1401,10 @@ struct softnet_data {
struct napi_struct backlog; 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 #ifdef CONFIG_RPS
queue->input_queue_head++; sd->input_queue_head++;
#endif #endif
} }

149
net/core/dev.c
View file

@ -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)]; 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 #ifdef CONFIG_RPS
spin_lock(&queue->input_pkt_queue.lock); spin_lock(&sd->input_pkt_queue.lock);
#endif #endif
} }
static inline void rps_unlock(struct softnet_data *queue) static inline void rps_unlock(struct softnet_data *sd)
{ {
#ifdef CONFIG_RPS #ifdef CONFIG_RPS
spin_unlock(&queue->input_pkt_queue.lock); spin_unlock(&sd->input_pkt_queue.lock);
#endif #endif
} }
@ -2346,14 +2346,37 @@ done:
} }
/* Called from hardirq (IPI) context */ /* Called from hardirq (IPI) context */
static void trigger_softirq(void *data) static void rps_trigger_softirq(void *data)
{ {
struct softnet_data *queue = data; struct softnet_data *sd = data;
__napi_schedule(&queue->backlog);
__napi_schedule(&sd->backlog);
__get_cpu_var(netdev_rx_stat).received_rps++; __get_cpu_var(netdev_rx_stat).received_rps++;
} }
#endif /* CONFIG_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 * enqueue_to_backlog is called to queue an skb to a per CPU backlog
* queue (may be a remote CPU queue). * 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, static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
unsigned int *qtail) unsigned int *qtail)
{ {
struct softnet_data *queue; struct softnet_data *sd;
unsigned long flags; unsigned long flags;
queue = &per_cpu(softnet_data, cpu); sd = &per_cpu(softnet_data, cpu);
local_irq_save(flags); local_irq_save(flags);
__get_cpu_var(netdev_rx_stat).total++; __get_cpu_var(netdev_rx_stat).total++;
rps_lock(queue); rps_lock(sd);
if (queue->input_pkt_queue.qlen <= netdev_max_backlog) { if (sd->input_pkt_queue.qlen <= netdev_max_backlog) {
if (queue->input_pkt_queue.qlen) { if (sd->input_pkt_queue.qlen) {
enqueue: enqueue:
__skb_queue_tail(&queue->input_pkt_queue, skb); __skb_queue_tail(&sd->input_pkt_queue, skb);
#ifdef CONFIG_RPS #ifdef CONFIG_RPS
*qtail = queue->input_queue_head + *qtail = sd->input_queue_head + sd->input_pkt_queue.qlen;
queue->input_pkt_queue.qlen;
#endif #endif
rps_unlock(queue); rps_unlock(sd);
local_irq_restore(flags); local_irq_restore(flags);
return NET_RX_SUCCESS; return NET_RX_SUCCESS;
} }
/* Schedule NAPI for backlog device */ /* Schedule NAPI for backlog device */
if (napi_schedule_prep(&queue->backlog)) { if (napi_schedule_prep(&sd->backlog)) {
#ifdef CONFIG_RPS if (!rps_ipi_queued(sd))
if (cpu != smp_processor_id()) { __napi_schedule(&sd->backlog);
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);
} }
goto enqueue; goto enqueue;
} }
rps_unlock(queue); rps_unlock(sd);
__get_cpu_var(netdev_rx_stat).dropped++; __get_cpu_var(netdev_rx_stat).dropped++;
local_irq_restore(flags); local_irq_restore(flags);
@ -2903,17 +2914,17 @@ EXPORT_SYMBOL(netif_receive_skb);
static void flush_backlog(void *arg) static void flush_backlog(void *arg)
{ {
struct net_device *dev = 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; struct sk_buff *skb, *tmp;
rps_lock(queue); rps_lock(sd);
skb_queue_walk_safe(&queue->input_pkt_queue, skb, tmp) skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp)
if (skb->dev == dev) { if (skb->dev == dev) {
__skb_unlink(skb, &queue->input_pkt_queue); __skb_unlink(skb, &sd->input_pkt_queue);
kfree_skb(skb); 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) 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) static int process_backlog(struct napi_struct *napi, int quota)
{ {
int work = 0; 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; napi->weight = weight_p;
do { do {
struct sk_buff *skb; struct sk_buff *skb;
local_irq_disable(); local_irq_disable();
rps_lock(queue); rps_lock(sd);
skb = __skb_dequeue(&queue->input_pkt_queue); skb = __skb_dequeue(&sd->input_pkt_queue);
if (!skb) { if (!skb) {
__napi_complete(napi); __napi_complete(napi);
rps_unlock(queue); rps_unlock(sd);
local_irq_enable(); local_irq_enable();
break; break;
} }
incr_input_queue_head(queue); input_queue_head_incr(sd);
rps_unlock(queue); rps_unlock(sd);
local_irq_enable(); local_irq_enable();
__netif_receive_skb(skb); __netif_receive_skb(skb);
@ -3331,24 +3342,25 @@ EXPORT_SYMBOL(netif_napi_del);
* net_rps_action sends any pending IPI's for rps. * net_rps_action sends any pending IPI's for rps.
* Note: called with local irq disabled, but exits with local irq enabled. * 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 #ifdef CONFIG_RPS
struct softnet_data *locqueue = &__get_cpu_var(softnet_data); struct softnet_data *sd = &__get_cpu_var(softnet_data);
struct softnet_data *remqueue = locqueue->rps_ipi_list; struct softnet_data *remsd = sd->rps_ipi_list;
if (remqueue) { if (remsd) {
locqueue->rps_ipi_list = NULL; sd->rps_ipi_list = NULL;
local_irq_enable(); local_irq_enable();
/* Send pending IPI's to kick RPS processing on remote cpus. */ /* Send pending IPI's to kick RPS processing on remote cpus. */
while (remqueue) { while (remsd) {
struct softnet_data *next = remqueue->rps_ipi_next; struct softnet_data *next = remsd->rps_ipi_next;
if (cpu_online(remqueue->cpu))
__smp_call_function_single(remqueue->cpu, if (cpu_online(remsd->cpu))
&remqueue->csd, 0); __smp_call_function_single(remsd->cpu,
remqueue = next; &remsd->csd, 0);
remsd = next;
} }
} else } else
#endif #endif
@ -3423,7 +3435,7 @@ static void net_rx_action(struct softirq_action *h)
netpoll_poll_unlock(have); netpoll_poll_unlock(have);
} }
out: out:
net_rps_action(); net_rps_action_and_irq_disable();
#ifdef CONFIG_NET_DMA #ifdef CONFIG_NET_DMA
/* /*
@ -5595,7 +5607,7 @@ static int dev_cpu_callback(struct notifier_block *nfb,
/* Process offline CPU's input_pkt_queue */ /* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
netif_rx(skb); netif_rx(skb);
incr_input_queue_head(oldsd); input_queue_head_incr(oldsd);
} }
return NOTIFY_OK; return NOTIFY_OK;
@ -5812,24 +5824,23 @@ static int __init net_dev_init(void)
*/ */
for_each_possible_cpu(i) { 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(&sd->input_pkt_queue);
skb_queue_head_init(&queue->input_pkt_queue); sd->completion_queue = NULL;
queue->completion_queue = NULL; INIT_LIST_HEAD(&sd->poll_list);
INIT_LIST_HEAD(&queue->poll_list);
#ifdef CONFIG_RPS #ifdef CONFIG_RPS
queue->csd.func = trigger_softirq; sd->csd.func = rps_trigger_softirq;
queue->csd.info = queue; sd->csd.info = sd;
queue->csd.flags = 0; sd->csd.flags = 0;
queue->cpu = i; sd->cpu = i;
#endif #endif
queue->backlog.poll = process_backlog; sd->backlog.poll = process_backlog;
queue->backlog.weight = weight_p; sd->backlog.weight = weight_p;
queue->backlog.gro_list = NULL; sd->backlog.gro_list = NULL;
queue->backlog.gro_count = 0; sd->backlog.gro_count = 0;
} }
dev_boot_phase = 0; dev_boot_phase = 0;