From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arjan van de Ven Subject: Re: Printing the driver name as part of the netdev watchdog message Date: Sun, 6 Jul 2008 21:34:27 -0700 Message-ID: <20080706213427.406e8f29@infradead.org> References: <20080706.155318.46569612.davem@davemloft.net> <20080706165655.0783348b@infradead.org> <487176A2.6080604@cn.fujitsu.com> <20080706.205905.159207367.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: wangchen@cn.fujitsu.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from casper.infradead.org ([85.118.1.10]:45131 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750807AbYGGEes (ORCPT ); Mon, 7 Jul 2008 00:34:48 -0400 In-Reply-To: <20080706.205905.159207367.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 06 Jul 2008 20:59:05 -0700 (PDT) David Miller wrote: > > Also correct. ok updated version below; I also added an explicit comment for the ethtool locking From: Arjan van de Ven Subject: Use WARN_ONCE() in the netdev timeout handler (and print module name) As suggested by Dave: This patch adds a function to get the driver name from a struct net_device, and consequently uses this in the watchdog timeout handler to print as part of the message. To make this useful, use WARN_ONCE() so that the message is part of the ===[ cut here ]=== section, meaning that people are more likely to report it, and automated warning collection will pick it up. Signed-off-by: Arjan van de Ven --- include/linux/netdevice.h | 3 +++ net/core/dev.c | 41 ++++++++++++++++++++++++++++++++++++++--- net/sched/sch_generic.c | 9 +++++---- 3 files changed, 46 insertions(+), 7 deletions(-) Index: linux.trees.git/include/linux/netdevice.h =================================================================== --- linux.trees.git.orig/include/linux/netdevice.h +++ linux.trees.git/include/linux/netdevice.h @@ -1514,6 +1514,9 @@ extern void dev_seq_stop(struct seq_file extern int netdev_class_create_file(struct class_attribute *class_attr); extern void netdev_class_remove_file(struct class_attribute *class_attr); +extern void netdev_drivername(struct net_device *dev, char *buffer, int len); + + extern void linkwatch_run_queue(void); extern int netdev_compute_features(unsigned long all, unsigned long one); Index: linux.trees.git/net/core/dev.c =================================================================== --- linux.trees.git.orig/net/core/dev.c +++ linux.trees.git/net/core/dev.c @@ -3706,10 +3706,8 @@ static void rollback_registered(struct n /* Some devices call without registering for initialization unwind. */ if (dev->reg_state == NETREG_UNINITIALIZED) { - printk(KERN_DEBUG "unregister_netdevice: device %s/%p never " + WARN(1, KERN_DEBUG "unregister_netdevice: device %s/%p never " "was registered\n", dev->name, dev); - - WARN_ON(1); return; } @@ -4554,6 +4552,43 @@ err_name: return -ENOMEM; } +void netdev_drivername(struct net_device *dev, char *buffer, int len) +{ + struct device_driver *driver; + struct device *parent; + struct ethtool_drvinfo info; + const struct ethtool_ops *ops = dev->ethtool_ops; + + if (len <= 0) + return; + buffer[0] = 0; + + /* + * Note: in principle ethtool ops need to be called + * with the RTNL mutex held, while this function is called + * from IRQ context. However, get_drvinfo is a special exception + * (confirmed by Dave and Jeff) and doesn't need the mutex. + */ + if (ops && ops->get_drvinfo) { + memset(&info, 0, sizeof(info)); + info.cmd = ETHTOOL_GDRVINFO; + ops->get_drvinfo(dev, &info); + if (strlen(info.driver) > 0) { + strlcpy(buffer, info.driver, len); + return; + } + } + + parent = dev->dev.parent; + + if (!parent) + return; + + driver = parent->driver; + if (driver && driver->name) + strlcpy(buffer, driver->name, len); +} + static void __net_exit netdev_exit(struct net *net) { kfree(net->dev_name_head); Index: linux.trees.git/net/sched/sch_generic.c =================================================================== --- linux.trees.git.orig/net/sched/sch_generic.c +++ linux.trees.git/net/sched/sch_generic.c @@ -215,11 +215,12 @@ static void dev_watchdog(unsigned long a netif_carrier_ok(dev)) { if (netif_queue_stopped(dev) && time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) { - - printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", - dev->name); + char drivername[64]; + netdev_drivername(dev, drivername, 64); + WARN_ONCE(1, KERN_INFO + "NETDEV WATCHDOG: %s (%s): transmit timed out\n", + dev->name, drivername); dev->tx_timeout(dev); - WARN_ON_ONCE(1); } if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) dev_hold(dev);