Messages in this thread | | | Date | Tue, 19 Aug 2014 01:15:28 -0400 (EDT) | From | Pankaj Gupta <> | Subject | Re: [RFC 1/4] net: allow large number of rx queues |
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> 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 > >
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