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net: allow large number of tx queues

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netif_alloc_netdev_queues() uses kcalloc() to allocate memory
for the "struct netdev_queue *_tx" array.

For large number of tx queues, kcalloc() might fail, so this
patch does a fallback to vzalloc().

As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2013-06-20 01:15:51 -07:00 committed by David S. Miller
parent b0b02c77d7
commit 60877a32bc
1 changed files with 19 additions and 7 deletions
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22
net/core/dev.c
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@ -130,6 +130,7 @@
#include <linux/cpu_rmap.h>
#include <linux/static_key.h>
#include <linux/hashtable.h>
#include <linux/vmalloc.h>
#include "net-sysfs.h"
@ -5253,17 +5254,28 @@ static void netdev_init_one_queue(struct net_device *dev,
#endif
}
static void netif_free_tx_queues(struct net_device *dev)
{
if (is_vmalloc_addr(dev->_tx))
vfree(dev->_tx);
else
kfree(dev->_tx);
}
static int netif_alloc_netdev_queues(struct net_device *dev)
{
unsigned int count = dev->num_tx_queues;
struct netdev_queue *tx;
size_t sz = count * sizeof(*tx);
BUG_ON(count < 1);
BUG_ON(count < 1 || count > 0xffff);
tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
if (!tx) {
tx = vzalloc(sz);
if (!tx)
return -ENOMEM;
}
dev->_tx = tx;
netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
@ -5811,7 +5823,7 @@ free_all:
free_pcpu:
free_percpu(dev->pcpu_refcnt);
kfree(dev->_tx);
netif_free_tx_queues(dev);
#ifdef CONFIG_RPS
kfree(dev->_rx);
#endif
@ -5836,7 +5848,7 @@ void free_netdev(struct net_device *dev)
release_net(dev_net(dev));
kfree(dev->_tx);
netif_free_tx_queues(dev);
#ifdef CONFIG_RPS
kfree(dev->_rx);
#endif