lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 3 Dec 2014 11:42:24 +0200 From: "Michael S. Tsirkin" <mst@...hat.com> To: Pankaj Gupta <pagupta@...hat.com> Cc: linux-kernel@...r.kernel.org, netdev@...r.kernel.org, davem@...emloft.net, jasowang@...hat.com, dgibson@...hat.com, vfalico@...il.com, edumazet@...gle.com, vyasevic@...hat.com, hkchu@...gle.com, wuzhy@...ux.vnet.ibm.com, xemul@...allels.com, therbert@...gle.com, bhutchings@...arflare.com, xii@...gle.com, stephen@...workplumber.org, jiri@...nulli.us, sergei.shtylyov@...entembedded.com Subject: Re: [PATCH v3 net-next 1/2] net: allow large number of rx queues 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@...hat.com> > Reviewed-by: Michael S. Tsirkin <mst@...hat.com> > Reviewed-by: David Gibson <dgibson@...hat.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@...r.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@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists