From 9136461ab921fd5066ba6a0de08399e2172f4d71 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 11 Jun 2012 06:36:13 +0000 Subject: net: keep name_hlist close to name __dev_get_by_name() is slow because pm_qos_req has been inserted between name[] and name_hlist, adding cache misses. pm_qos_req has nothing to do at the beginning of struct net_device Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/netdevice.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d94cb1431519..a0b84e3b087c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1046,10 +1046,9 @@ struct net_device { */ char name[IFNAMSIZ]; - struct pm_qos_request pm_qos_req; - - /* device name hash chain */ + /* device name hash chain, please keep it close to name[] */ struct hlist_node name_hlist; + /* snmp alias */ char *ifalias; @@ -1322,6 +1321,8 @@ struct net_device { /* group the device belongs to */ int group; + + struct pm_qos_request pm_qos_req; }; #define to_net_dev(d) container_of(d, struct net_device, dev) -- cgit v1.2.3 From 95603e2293de556de7e82221649bfd7fd98b64a3 Mon Sep 17 00:00:00 2001 From: Michel Machado Date: Tue, 12 Jun 2012 10:16:35 +0000 Subject: net-next: add dev_loopback_xmit() to avoid duplicate code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add dev_loopback_xmit() in order to deduplicate functions ip_dev_loopback_xmit() (in net/ipv4/ip_output.c) and ip6_dev_loopback_xmit() (in net/ipv6/ip6_output.c). I was about to reinvent the wheel when I noticed that ip_dev_loopback_xmit() and ip6_dev_loopback_xmit() do exactly what I need and are not IP-only functions, but they were not available to reuse elsewhere. ip6_dev_loopback_xmit() does not have line "skb_dst_force(skb);", but I understand that this is harmless, and should be in dev_loopback_xmit(). Signed-off-by: Michel Machado CC: "David S. Miller" CC: Alexey Kuznetsov CC: James Morris CC: Hideaki YOSHIFUJI CC: Patrick McHardy CC: Eric Dumazet CC: Jiri Pirko CC: "Michał Mirosław" CC: Ben Hutchings Signed-off-by: David S. Miller --- include/linux/netdevice.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a0b84e3b087c..2c2ecea28a1b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1627,6 +1627,7 @@ extern int dev_alloc_name(struct net_device *dev, const char *name); extern int dev_open(struct net_device *dev); extern int dev_close(struct net_device *dev); extern void dev_disable_lro(struct net_device *dev); +extern int dev_loopback_xmit(struct sk_buff *newskb); extern int dev_queue_xmit(struct sk_buff *skb); extern int register_netdevice(struct net_device *dev); extern void unregister_netdevice_queue(struct net_device *dev, -- cgit v1.2.3 From 16917b87a23b429226527f393270047069d665e9 Mon Sep 17 00:00:00 2001 From: Yuval Mintz Date: Sun, 1 Jul 2012 03:18:50 +0000 Subject: net-next: Add netif_get_num_default_rss_queues Most multi-queue networking driver consider the number of online cpus when configuring RSS queues. This patch adds a wrapper to the number of cpus, setting an upper limit on the number of cpus a driver should consider (by default) when allocating resources for his queues. Signed-off-by: Yuval Mintz Signed-off-by: Eilon Greenstein Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2c2ecea28a1b..ab0251d541ab 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2119,6 +2119,9 @@ static inline int netif_copy_real_num_queues(struct net_device *to_dev, #endif } +#define DEFAULT_MAX_NUM_RSS_QUEUES (8) +extern int netif_get_num_default_rss_queues(void); + /* Use this variant when it is known for sure that it * is executing from hardware interrupt context or with hardware interrupts * disabled. -- cgit v1.2.3 From ee6ae1a1d58c70fc864bc777a36be56b0880ebff Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Fri, 20 Jul 2012 02:28:46 +0000 Subject: net: honour netif_set_real_num_tx_queues() retval In netif_copy_real_num_queues() the return value of netif_set_real_num_tx_queues() should be checked. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/netdevice.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ab0251d541ab..eb06e58bed0b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2110,7 +2110,12 @@ static inline int netif_set_real_num_rx_queues(struct net_device *dev, static inline int netif_copy_real_num_queues(struct net_device *to_dev, const struct net_device *from_dev) { - netif_set_real_num_tx_queues(to_dev, from_dev->real_num_tx_queues); + int err; + + err = netif_set_real_num_tx_queues(to_dev, + from_dev->real_num_tx_queues); + if (err) + return err; #ifdef CONFIG_RPS return netif_set_real_num_rx_queues(to_dev, from_dev->real_num_rx_queues); -- cgit v1.2.3 From 30b678d844af3305cda5953467005cebb5d7b687 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 30 Jul 2012 15:57:00 +0000 Subject: net: Allow driver to limit number of GSO segments per skb A peer (or local user) may cause TCP to use a nominal MSS of as little as 88 (actual MSS of 76 with timestamps). Given that we have a sufficiently prodigious local sender and the peer ACKs quickly enough, it is nevertheless possible to grow the window for such a connection to the point that we will try to send just under 64K at once. This results in a single skb that expands to 861 segments. In some drivers with TSO support, such an skb will require hundreds of DMA descriptors; a substantial fraction of a TX ring or even more than a full ring. The TX queue selected for the skb may stall and trigger the TX watchdog repeatedly (since the problem skb will be retried after the TX reset). This particularly affects sfc, for which the issue is designated as CVE-2012-3412. Therefore: 1. Add the field net_device::gso_max_segs holding the device-specific limit. 2. In netif_skb_features(), if the number of segments is too high then mask out GSO features to force fall back to software GSO. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- include/linux/netdevice.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index eb06e58bed0b..a9db4f33407f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1300,6 +1300,8 @@ struct net_device { /* for setting kernel sock attribute on TCP connection setup */ #define GSO_MAX_SIZE 65536 unsigned int gso_max_size; +#define GSO_MAX_SEGS 65535 + u16 gso_max_segs; #ifdef CONFIG_DCB /* Data Center Bridging netlink ops */ -- cgit v1.2.3