Re: linux-next: Tree for March 22 (net-sysfs.c)

Eric Dumazet
2010-03-22T20:48:52Z

Le lundi 22 mars 2010 à 10:22 -0700, David Miller a écrit :
> From: Randy Dunlap <randy.dunlap@oracle.com>
> Date: Mon, 22 Mar 2010 08:31:09 -0700
>
> > When CONFIG_SYSFS is not enabled:
> >
> > net/core/net-sysfs.c:742: error: implicit declaration of function 'rx_queue_remove_kobjects'
> > net/core/net-sysfs.c:783: error: implicit declaration of function 'rx_queue_register_kobjects'
> >
>

I cooked following patch and added a new CONFIG_RPS setting, I believe
its cleaner and could help.

Thanks

[PATCH net-next-2.6] net: RPS depends on CONFIG_SYSFS

Randy Dunlap found net/core/net-sysfs.c could not compile if
CONFIG_SYSFS=n

Defines CONFIG_RPS in net/Kconfig to let user disable RPS if wanted.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
include/linux/netdevice.h | 4 ++++
net/Kconfig | 5 +++++
net/core/dev.c | 29 +++++++++++++++++++----------
net/core/net-sysfs.c | 7 ++++++-
4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c96c41e..c94cdb4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -531,6 +531,7 @@ struct netdev_queue {
unsigned long tx_dropped;
} ____cacheline_aligned_in_smp;

+#if defined(CONFIG_RPS)
/*
* This structure holds an RPS map which can be of variable length. The
* map is an array of CPUs.
@@ -549,6 +550,7 @@ struct netdev_rx_queue {
struct netdev_rx_queue *first;
atomic_t count;
} ____cacheline_aligned_in_smp;
+#endif

/*
* This structure defines the management hooks for network devices.
@@ -897,12 +899,14 @@ struct net_device {

unsigned char broadcast[MAX_ADDR_LEN]; /* hw bcast add */

+#ifdef CONFIG_RPS
struct kset *queues_kset;

struct netdev_rx_queue *_rx;

/* Number of RX queues allocated at alloc_netdev_mq() time */
unsigned int num_rx_queues;
+#endif

struct netdev_queue rx_queue;

diff --git a/net/Kconfig b/net/Kconfig
index 041c35e..8189502 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -203,6 +203,11 @@ source "net/ieee802154/Kconfig"
source "net/sched/Kconfig"
source "net/dcb/Kconfig"

+config RPS
+ boolean "RPS: Remote Packet Steering"
+ depends on SMP && SYSFS
+ default y
+
menu "Network testing"

config NET_PKTGEN
diff --git a/net/core/dev.c b/net/core/dev.c
index a03aab4..0ea0f96 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2177,7 +2177,7 @@ int weight_p __read_mostly = 64; /* old backlog weight */

DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };

-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
/*
* get_rps_cpu is called from netif_receive_skb and returns the target
* CPU from the RPS map of the receiving queue for a given skb.
@@ -2325,7 +2325,7 @@ enqueue:

/* Schedule NAPI for backlog device */
if (napi_schedule_prep(&queue->backlog)) {
-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
if (cpu != smp_processor_id()) {
struct rps_remote_softirq_cpus *rcpus =
&__get_cpu_var(rps_remote_softirq_cpus);
@@ -2376,7 +2376,7 @@ int netif_rx(struct sk_buff *skb)
if (!skb->tstamp.tv64)
net_timestamp(skb);

-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
cpu = get_rps_cpu(skb->dev, skb);
if (cpu < 0)
cpu = smp_processor_id();
@@ -2750,7 +2750,7 @@ out:
*/
int netif_receive_skb(struct sk_buff *skb)
{
-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
int cpu;

cpu = get_rps_cpu(skb->dev, skb);
@@ -3187,7 +3187,7 @@ void netif_napi_del(struct napi_struct *napi)
}
EXPORT_SYMBOL(netif_napi_del);

-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
/*
* net_rps_action sends any pending IPI's for rps. This is only called from
* softirq and interrupts must be enabled.
@@ -3212,7 +3212,7 @@ static void net_rx_action(struct softirq_action *h)
unsigned long time_limit = jiffies + 2;
int budget = netdev_budget;
void *have;
-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
int select;
struct rps_remote_softirq_cpus *rcpus;
#endif
@@ -3278,7 +3278,7 @@ static void net_rx_action(struct softirq_action *h)
netpoll_poll_unlock(have);
}
out:
-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
rcpus = &__get_cpu_var(rps_remote_softirq_cpus);
select = rcpus->select;
rcpus->select ^= 1;
@@ -5275,6 +5275,7 @@ int register_netdevice(struct net_device *dev)

dev->iflink = -1;

+#ifdef CONFIG_RPS
if (!dev->num_rx_queues) {
/*
* Allocate a single RX queue if driver never called
@@ -5291,7 +5292,7 @@ int register_netdevice(struct net_device *dev)
atomic_set(&dev->_rx->count, 1);
dev->num_rx_queues = 1;
}
-
+#endif
/* Init, if this function is available */
if (dev->netdev_ops->ndo_init) {
ret = dev->netdev_ops->ndo_init(dev);
@@ -5649,11 +5650,13 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
void (*setup)(struct net_device *), unsigned int queue_count)
{
struct netdev_queue *tx;
- struct netdev_rx_queue *rx;
struct net_device *dev;
size_t alloc_size;
struct net_device *p;
+#ifdef CONFIG_RPS
+ struct netdev_rx_queue *rx;
int i;
+#endif

BUG_ON(strlen(name) >= sizeof(dev->name));

@@ -5679,6 +5682,7 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
goto free_p;
}

+#ifdef CONFIG_RPS
rx = kcalloc(queue_count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
if (!rx) {
printk(KERN_ERR "alloc_netdev: Unable to allocate "
@@ -5694,6 +5698,7 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
*/
for (i = 0; i < queue_count; i++)
rx[i].first = rx;
+#endif

dev = PTR_ALIGN(p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
@@ -5709,8 +5714,10 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
dev->num_tx_queues = queue_count;
dev->real_num_tx_queues = queue_count;

+#ifdef CONFIG_RPS
dev->_rx = rx;
dev->num_rx_queues = queue_count;
+#endif

dev->gso_max_size = GSO_MAX_SIZE;

@@ -5727,8 +5734,10 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
return dev;

free_rx:
+#ifdef CONFIG_RPS
kfree(rx);
free_tx:
+#endif
kfree(tx);
free_p:
kfree(p);
@@ -6232,7 +6241,7 @@ static int __init net_dev_init(void)
queue->completion_queue = NULL;
INIT_LIST_HEAD(&queue->poll_list);

-#ifdef CONFIG_SMP
+#ifdef CONFIG_RPS
queue->csd.func = trigger_softirq;
queue->csd.info = queue;
queue->csd.flags = 0;
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 7a46343..1e7fdd6 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -466,6 +466,7 @@ static struct attribute_group wireless_group = {
};
#endif

+#ifdef CONFIG_RPS
/*
* RX queue sysfs structures and functions.
*/
@@ -675,7 +676,7 @@ static void rx_queue_remove_kobjects(struct net_device *net)
kobject_put(&net->_rx[i].kobj);
kset_unregister(net->queues_kset);
}
-
+#endif /* CONFIG_RPS */
#endif /* CONFIG_SYSFS */

#ifdef CONFIG_HOTPLUG
@@ -739,7 +740,9 @@ void netdev_unregister_kobject(struct net_device * net)
if (!net_eq(dev_net(net), &init_net))
return;

+#ifdef CONFIG_RPS
rx_queue_remove_kobjects(net);
+#endif

device_del(dev);
}
@@ -780,11 +783,13 @@ int netdev_register_kobject(struct net_device *net)
if (error)
return error;

+#ifdef CONFIG_RPS
error = rx_queue_register_kobjects(net);
if (error) {
device_del(dev);
return error;
}
+#endif

return error;
}