Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933736Ab3FSFvh (ORCPT ); Wed, 19 Jun 2013 01:51:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2719 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756449Ab3FSFvg (ORCPT ); Wed, 19 Jun 2013 01:51:36 -0400 From: Jason Wang To: davem@davemloft.net, edumazet@google.com, hkchu@google.com, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jason Wang Subject: [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array Date: Wed, 19 Jun 2013 13:40:50 +0800 Message-Id: <1371620452-49349-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1371620452-49349-1-git-send-email-jasowang@redhat.com> References: <1371620452-49349-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7732 Lines: 264 Currently, we use kcalloc to allocate rx/tx queues for a net device which could be easily lead to a high order memory allocation request when initializing a multiqueue net device. We can simply avoid this by switching to use flex array which always allocate at order zero. Signed-off-by: Jason Wang --- include/linux/netdevice.h | 13 ++++++---- net/core/dev.c | 57 ++++++++++++++++++++++++++++++++------------ net/core/net-sysfs.c | 15 +++++++---- 3 files changed, 58 insertions(+), 27 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 09b4188..c0b5d04 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -1230,7 +1231,7 @@ struct net_device { #ifdef CONFIG_RPS - struct netdev_rx_queue *_rx; + struct flex_array *_rx; /* Number of RX queues allocated at register_netdev() time */ unsigned int num_rx_queues; @@ -1250,7 +1251,7 @@ struct net_device { /* * Cache lines mostly used on transmit path */ - struct netdev_queue *_tx ____cacheline_aligned_in_smp; + struct flex_array *_tx ____cacheline_aligned_in_smp; /* Number of TX queues allocated at alloc_netdev_mq() time */ unsigned int num_tx_queues; @@ -1434,7 +1435,7 @@ static inline struct netdev_queue *netdev_get_tx_queue(const struct net_device *dev, unsigned int index) { - return &dev->_tx[index]; + return flex_array_get(dev->_tx, index); } static inline void netdev_for_each_tx_queue(struct net_device *dev, @@ -1445,8 +1446,10 @@ static inline void netdev_for_each_tx_queue(struct net_device *dev, { unsigned int i; - for (i = 0; i < dev->num_tx_queues; i++) - f(dev, &dev->_tx[i], arg); + for (i = 0; i < dev->num_tx_queues; i++) { + struct netdev_queue *txq = flex_array_get(dev->_tx, i); + f(dev, txq, arg); + } } extern struct netdev_queue *netdev_pick_tx(struct net_device *dev, diff --git a/net/core/dev.c b/net/core/dev.c index fa007db..3a4ecb1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -130,6 +130,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -2902,7 +2903,7 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb, if (rxq_index == skb_get_rx_queue(skb)) goto out; - rxqueue = dev->_rx + rxq_index; + rxqueue = flex_array_get(dev->_rx, rxq_index); flow_table = rcu_dereference(rxqueue->rps_flow_table); if (!flow_table) goto out; @@ -2950,9 +2951,9 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, dev->name, index, dev->real_num_rx_queues); goto done; } - rxqueue = dev->_rx + index; + rxqueue = flex_array_get(dev->_rx, index); } else - rxqueue = dev->_rx; + rxqueue = flex_array_get(dev->_rx, 0); map = rcu_dereference(rxqueue->rps_map); if (map) { @@ -3038,7 +3039,7 @@ done: bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, u32 flow_id, u16 filter_id) { - struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index; + struct netdev_rx_queue *rxqueue = flex_array_get(dev->_rx, rxq_index); struct rps_dev_flow_table *flow_table; struct rps_dev_flow *rflow; bool expire = true; @@ -5223,18 +5224,31 @@ EXPORT_SYMBOL(netif_stacked_transfer_operstate); static int netif_alloc_rx_queues(struct net_device *dev) { unsigned int i, count = dev->num_rx_queues; - struct netdev_rx_queue *rx; + struct flex_array *rx; + int err; BUG_ON(count < 1); - rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL); - if (!rx) + rx = flex_array_alloc(sizeof(struct netdev_rx_queue), count, + GFP_KERNEL | __GFP_ZERO); + if (!rx) { + pr_err("netdev: Unable to allocate flex array for rx queues\n"); return -ENOMEM; + } + + err = flex_array_prealloc(rx, 0, count, GFP_KERNEL | __GFP_ZERO); + if (err) { + pr_err("netdev, Unable to prealloc %u rx qeueus\n", count); + flex_array_free(rx); + return err; + } dev->_rx = rx; - for (i = 0; i < count; i++) - rx[i].dev = dev; + for (i = 0; i < count; i++) { + struct netdev_rx_queue *rxq = flex_array_get(rx, i); + rxq->dev = dev; + } return 0; } #endif @@ -5256,13 +5270,24 @@ static void netdev_init_one_queue(struct net_device *dev, static int netif_alloc_netdev_queues(struct net_device *dev) { unsigned int count = dev->num_tx_queues; - struct netdev_queue *tx; + struct flex_array *tx; + int err; BUG_ON(count < 1); - tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL); - if (!tx) + tx = flex_array_alloc(sizeof(struct netdev_queue), count, + GFP_KERNEL | __GFP_ZERO); + if (!tx) { + pr_err("netdev: Unable to allocate flex array for tx queues\n"); return -ENOMEM; + } + + err = flex_array_prealloc(tx, 0, count, GFP_KERNEL | __GFP_ZERO); + if (err) { + pr_err("netdev, Unable to prealloc %u tx qeueus\n", count); + flex_array_free(tx); + return err; + } dev->_tx = tx; @@ -5811,9 +5836,9 @@ free_all: free_pcpu: free_percpu(dev->pcpu_refcnt); - kfree(dev->_tx); + flex_array_free(dev->_tx); #ifdef CONFIG_RPS - kfree(dev->_rx); + flex_array_free(dev->_rx); #endif free_p: @@ -5836,9 +5861,9 @@ void free_netdev(struct net_device *dev) release_net(dev_net(dev)); - kfree(dev->_tx); + flex_array_free(dev->_tx); #ifdef CONFIG_RPS - kfree(dev->_rx); + flex_array_free(dev->_rx); #endif kfree(rcu_dereference_protected(dev->ingress_queue, 1)); diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 981fed3..4328c3a 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -717,7 +718,7 @@ static struct kobj_type rx_queue_ktype = { static int rx_queue_add_kobject(struct net_device *net, int index) { - struct netdev_rx_queue *queue = net->_rx + index; + struct netdev_rx_queue *queue = flex_array_get(net->_rx, index); struct kobject *kobj = &queue->kobj; int error = 0; @@ -751,8 +752,10 @@ net_rx_queue_update_kobjects(struct net_device *net, int old_num, int new_num) } } - while (--i >= new_num) - kobject_put(&net->_rx[i].kobj); + while (--i >= new_num) { + struct netdev_rx_queue *rxq = flex_array_get(net->_rx, i); + kobject_put(&rxq->kobj); + } return error; #else @@ -939,7 +942,7 @@ static inline unsigned int get_netdev_queue_index(struct netdev_queue *queue) int i; for (i = 0; i < dev->num_tx_queues; i++) - if (queue == &dev->_tx[i]) + if (queue == (struct netdev_queue *)flex_array_get(dev->_tx, i)) break; BUG_ON(i >= dev->num_tx_queues); @@ -1051,7 +1054,7 @@ static struct kobj_type netdev_queue_ktype = { static int netdev_queue_add_kobject(struct net_device *net, int index) { - struct netdev_queue *queue = net->_tx + index; + struct netdev_queue *queue = flex_array_get(net->_tx, index); struct kobject *kobj = &queue->kobj; int error = 0; @@ -1093,7 +1096,7 @@ netdev_queue_update_kobjects(struct net_device *net, int old_num, int new_num) } while (--i >= new_num) { - struct netdev_queue *queue = net->_tx + i; + struct netdev_queue *queue = flex_array_get(net->_tx, i); #ifdef CONFIG_BQL sysfs_remove_group(&queue->kobj, &dql_group); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/