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Commit 60877a32 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: allow large number of tx queues 



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: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b0b02c77

net/core/dev.c

+19 −7
Original line number Diff line number Diff line
@@ -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 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, 


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