From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pravin B Shelar Subject: [PATCH net-next v4 04/11] net: Export xmit_recursion Date: Wed, 16 Jul 2014 17:18:30 -0700 Message-ID: <1405556310-1769-1-git-send-email-pshelar@nicira.com> Cc: netdev@vger.kernel.org, Pravin B Shelar To: davem@davemloft.net Return-path: Received: from na3sys009aog106.obsmtp.com ([74.125.149.77]:33657 "HELO na3sys009aog106.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753720AbaGQASc (ORCPT ); Wed, 16 Jul 2014 20:18:32 -0400 Received: by mail-pa0-f47.google.com with SMTP id kx10so2203452pab.6 for ; Wed, 16 Jul 2014 17:18:32 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Next patch adds re-circulation action to OVS. This is recursive action needs to be limited to safe number recursions to avoid overflowing kernel stack space. This patch export xmit_recursion so that OVS can increment and check the value before executing recirc action. Signed-off-by: Pravin B Shelar --- include/linux/netdevice.h | 3 +++ net/core/dev.c | 10 +++++----- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3a320db..ca7a1ab 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1941,6 +1941,9 @@ static inline struct net_device *first_net_device_rcu(struct net *net) return lh == &net->dev_base_head ? NULL : net_device_entry(lh); } +#define NET_RECURSION_LIMIT 10 +DECLARE_PER_CPU(int, net_xmit_recursion); + int netdev_boot_setup_check(struct net_device *dev); unsigned long netdev_boot_base(const char *prefix, int unit); struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type, diff --git a/net/core/dev.c b/net/core/dev.c index 6e2a2cd..7f36a4f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2804,8 +2804,8 @@ static void skb_update_prio(struct sk_buff *skb) #define skb_update_prio(skb) #endif -static DEFINE_PER_CPU(int, xmit_recursion); -#define RECURSION_LIMIT 10 +DEFINE_PER_CPU(int, net_xmit_recursion); +EXPORT_SYMBOL_GPL(net_xmit_recursion); /** * dev_loopback_xmit - loop back @skb @@ -2895,15 +2895,15 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) if (txq->xmit_lock_owner != cpu) { - if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT) + if (__this_cpu_read(net_xmit_recursion) > NET_RECURSION_LIMIT) goto recursion_alert; HARD_TX_LOCK(dev, txq, cpu); if (!netif_xmit_stopped(txq)) { - __this_cpu_inc(xmit_recursion); + __this_cpu_inc(net_xmit_recursion); rc = dev_hard_start_xmit(skb, dev, txq); - __this_cpu_dec(xmit_recursion); + __this_cpu_dec(net_xmit_recursion); if (dev_xmit_complete(rc)) { HARD_TX_UNLOCK(dev, txq); goto out; -- 1.9.3