From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array Date: Wed, 19 Jun 2013 08:58:31 -0700 Message-ID: <1371657511.3252.324.camel@edumazet-glaptop> References: <1371620452-49349-1-git-send-email-jasowang@redhat.com> <1371620452-49349-2-git-send-email-jasowang@redhat.com> <1371623518.3252.267.camel@edumazet-glaptop> <20130619091132.GA2816@redhat.com> <1371635763.3252.289.camel@edumazet-glaptop> <20130619154059.GA13735@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Jason Wang , davem@davemloft.net, edumazet@google.com, hkchu@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20130619154059.GA13735@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2013-06-19 at 18:40 +0300, Michael S. Tsirkin wrote: > That's a good trick too - vmalloc memory is a bit slower > on x86 since it's not using a huge page, but that's only > when we have lots of CPUs/queues... > > Short term - how about switching to vmalloc if > 32 queues? You do not have to switch "if > 32 queues" diff --git a/net/core/dev.c b/net/core/dev.c index fa007db..473cc9e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -130,6 +130,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -5253,6 +5254,14 @@ static void netdev_init_one_queue(struct net_device *dev, #endif } +static void netif_free_tx_queues(struct net_device *dev) +{ + if (is_vmalloc_addr(dev->_tx)) + vfree(dev->_tx); + else + kfree(dev->_tx); +} + static int netif_alloc_netdev_queues(struct net_device *dev) { unsigned int count = dev->num_tx_queues; @@ -5261,9 +5270,11 @@ static int netif_alloc_netdev_queues(struct net_device *dev) BUG_ON(count < 1); tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL); - if (!tx) - return -ENOMEM; - + if (!tx) { + tx = vzalloc(count * sizeof(struct netdev_queue)); + if (!tx) + return -ENOMEM; + } dev->_tx = tx; netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL); @@ -5811,7 +5822,7 @@ free_all: free_pcpu: free_percpu(dev->pcpu_refcnt); - kfree(dev->_tx); + netif_free_tx_queues(dev); #ifdef CONFIG_RPS kfree(dev->_rx); #endif @@ -5836,7 +5847,7 @@ void free_netdev(struct net_device *dev) release_net(dev_net(dev)); - kfree(dev->_tx); + netif_free_tx_queues(dev); #ifdef CONFIG_RPS kfree(dev->_rx); #endif