From: Pankaj Gupta Date: Mon, 12 Jan 2015 06:11:28 +0000 (+0530) Subject: net: allow large number of rx queues X-Git-Tag: v4.0-rc1~133^2~245^2~1 X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=1059590254fa9dce9cafc4f07d1103dbec415e76 net: allow large number of rx queues 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 Reviewed-by: Michael S. Tsirkin Reviewed-by: David Gibson Signed-off-by: David S. Miller --- diff --git a/net/core/dev.c b/net/core/dev.c index 683d493aa1bf..805456147c30 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6172,13 +6172,16 @@ 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++) @@ -6808,7 +6811,7 @@ void free_netdev(struct net_device *dev) netif_free_tx_queues(dev); #ifdef CONFIG_SYSFS - kfree(dev->_rx); + kvfree(dev->_rx); #endif kfree(rcu_dereference_protected(dev->ingress_queue, 1));