Message ID | 1408369040-1216-2-git-send-email-pagupta@redhat.com |
---|---|
State | RFC, archived |
Delegated to: | David Miller |
Headers | show |
Hello. On 08/18/2014 05:37 PM, Pankaj Gupta wrote: > netif_alloc_rx_queues() uses kcalloc() to allocate memory > for "struct netdev_queue *_rx" array. > If we are doing large rx queue allocation kcalloc() might > fail, so this patch does a fallback to vzalloc(). > Similar implementation is done for tx queue allocation in > netif_alloc_netdev_queues(). > We avoid failure of high order memory allocation > with the help of vzalloc(), this allows us to do large > rx and tx queue allocation which in turn helps us to > increase the number of queues in tun. > As vmalloc() adds overhead on a critical network path, > __GFP_REPEAT flag is used with kzalloc() to do this fallback > only when really needed. > Signed-off-by: Pankaj Gupta <pagupta@redhat.com> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > Reviewed-by: David Gibson <dgibson@redhat.com> > --- > net/core/dev.c | 20 +++++++++++++------- > 1 file changed, 13 insertions(+), 7 deletions(-) > diff --git a/net/core/dev.c b/net/core/dev.c > index 1c15b18..a455a02 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct net_device *rootdev, > EXPORT_SYMBOL(netif_stacked_transfer_operstate); > > #ifdef CONFIG_SYSFS > +static void netif_free_rx_queues(struct net_device *dev) > +{ > + kvfree(dev->_rx); > +} > + > static int netif_alloc_rx_queues(struct net_device *dev) > { > unsigned int i, count = dev->num_rx_queues; > struct netdev_rx_queue *rx; > - > + size_t sz = count * sizeof(*rx); Please keep an empty line after declarations. > BUG_ON(count < 1); > WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> Hello. > > On 08/18/2014 05:37 PM, Pankaj Gupta wrote: > > > netif_alloc_rx_queues() uses kcalloc() to allocate memory > > for "struct netdev_queue *_rx" array. > > If we are doing large rx queue allocation kcalloc() might > > fail, so this patch does a fallback to vzalloc(). > > Similar implementation is done for tx queue allocation in > > netif_alloc_netdev_queues(). > > > We avoid failure of high order memory allocation > > with the help of vzalloc(), this allows us to do large > > rx and tx queue allocation which in turn helps us to > > increase the number of queues in tun. > > > As vmalloc() adds overhead on a critical network path, > > __GFP_REPEAT flag is used with kzalloc() to do this fallback > > only when really needed. > > > Signed-off-by: Pankaj Gupta <pagupta@redhat.com> > > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > > Reviewed-by: David Gibson <dgibson@redhat.com> > > --- > > net/core/dev.c | 20 +++++++++++++------- > > 1 file changed, 13 insertions(+), 7 deletions(-) > > > diff --git a/net/core/dev.c b/net/core/dev.c > > index 1c15b18..a455a02 100644 > > --- a/net/core/dev.c > > +++ b/net/core/dev.c > > @@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct > > net_device *rootdev, > > EXPORT_SYMBOL(netif_stacked_transfer_operstate); > > > > #ifdef CONFIG_SYSFS > > +static void netif_free_rx_queues(struct net_device *dev) > > +{ > > + kvfree(dev->_rx); > > +} > > + > > static int netif_alloc_rx_queues(struct net_device *dev) > > { > > unsigned int i, count = dev->num_rx_queues; > > struct netdev_rx_queue *rx; > > - > > + size_t sz = count * sizeof(*rx); > > Please keep an empty line after declarations. Yes, I will add it. Thanks > > > BUG_ON(count < 1); > > > > WBR, Sergei > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/dev.c b/net/core/dev.c index 1c15b18..a455a02 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5942,17 +5942,24 @@ void netif_stacked_transfer_operstate(const struct net_device *rootdev, EXPORT_SYMBOL(netif_stacked_transfer_operstate); #ifdef CONFIG_SYSFS +static void netif_free_rx_queues(struct net_device *dev) +{ + kvfree(dev->_rx); +} + static int netif_alloc_rx_queues(struct net_device *dev) { unsigned int i, count = dev->num_rx_queues; struct netdev_rx_queue *rx; - + size_t sz = count * sizeof(*rx); BUG_ON(count < 1); - rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL); - if (!rx) - return -ENOMEM; - + rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); + if (!rx) { + rx = vzalloc(sz); + if (!rx) + return -ENOMEM; + } dev->_rx = rx; for (i = 0; i < count; i++) @@ -6581,9 +6588,8 @@ void free_netdev(struct net_device *dev) netif_free_tx_queues(dev); #ifdef CONFIG_SYSFS - kfree(dev->_rx); + netif_free_rx_queues(dev); #endif - kfree(rcu_dereference_protected(dev->ingress_queue, 1)); /* Flush device addresses */