Message ID | 1417591177-7985-2-git-send-email-pagupta@redhat.com |
---|---|
State | Superseded, archived |
Delegated to: | David Miller |
Headers | show |
On Wed, Dec 03, 2014 at 12:49:36PM +0530, 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 | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index e916ba8..abe9560 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -6059,17 +6059,25 @@ 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); > +} > + I would just open-code this. > 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++) > @@ -6698,9 +6706,8 @@ void free_netdev(struct net_device *dev) > > netif_free_tx_queues(dev); > #ifdef CONFIG_SYSFS > - kfree(dev->_rx); > + netif_free_rx_queues(dev); > #endif > - and I think it's nicer with the empty line. > kfree(rcu_dereference_protected(dev->ingress_queue, 1)); > > /* Flush device addresses */ > -- > 1.8.3.1 > > -- > 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 -- 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
> > On Wed, Dec 03, 2014 at 12:49:36PM +0530, 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 | 19 +++++++++++++------ > > 1 file changed, 13 insertions(+), 6 deletions(-) > > > > diff --git a/net/core/dev.c b/net/core/dev.c > > index e916ba8..abe9560 100644 > > --- a/net/core/dev.c > > +++ b/net/core/dev.c > > @@ -6059,17 +6059,25 @@ 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); > > +} > > + > > I would just open-code this. I will make the changes with the next version. Thanks, Pankaj > > > 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++) > > @@ -6698,9 +6706,8 @@ void free_netdev(struct net_device *dev) > > > > netif_free_tx_queues(dev); > > #ifdef CONFIG_SYSFS > > - kfree(dev->_rx); > > + netif_free_rx_queues(dev); > > #endif > > - > > and I think it's nicer with the empty line. > > > kfree(rcu_dereference_protected(dev->ingress_queue, 1)); > > > > /* Flush device addresses */ > > -- > > 1.8.3.1 > > > > -- > > 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 > -- > 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 > -- 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 e916ba8..abe9560 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6059,17 +6059,25 @@ 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++) @@ -6698,9 +6706,8 @@ 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 */