On Wed, Jun 19, 2013 at 08:58:31AM -0700, Eric Dumazet wrote:
> On Wed, 2013-06-19 at 18:40 +0300, Michael S. Tsirkin wrote:
>
> > That's a good trick too - vmalloc memory is a bit slower
> > on x86 since it's not using a huge page, but that's only
> > when we have lots of CPUs/queues...
> >
> > Short term - how about switching to vmalloc if > 32 queues?
>
> You do not have to switch "if > 32 queues"
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index fa007db..473cc9e 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -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"
>
> @@ -5253,6 +5254,14 @@ 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;
> @@ -5261,9 +5270,11 @@ static int netif_alloc_netdev_queues(struct net_device
> *dev)
> BUG_ON(count < 1);
>
> tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
As we have explicit code to recover, maybe set __GFP_NOWARN?
If we are out of memory, vzalloc will warn too, we don't
need two warnings.
> - if (!tx)
> - return -ENOMEM;
> -
> + if (!tx) {
> + tx = vzalloc(count * sizeof(struct netdev_queue));
> + if (!tx)
> + return -ENOMEM;
> + }
> dev->_tx = tx;
>
> netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
> @@ -5811,7 +5822,7 @@ 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 +5847,7 @@ 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
>
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