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 16:56:55 -0700 Message-ID: <20080706165655.0783348b@infradead.org> References: <20080706130801.6bc36cf7@infradead.org> <20080706.155318.46569612.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from casper.infradead.org ([85.118.1.10]:36736 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754413AbYGFX5N (ORCPT ); Sun, 6 Jul 2008 19:57:13 -0400 In-Reply-To: <20080706.155318.46569612.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 06 Jul 2008 15:53:18 -0700 (PDT) David Miller wrote: > From: Arjan van de Ven > Date: Sun, 6 Jul 2008 13:08:01 -0700 > > > Does this patch look like the right approach for achieving the goal? > > It's almost there. > > You can issue an ethtool_ops->get_drvinfo() call, on devices which > support ethtool, and fetch the driver info from there. > > Your current method of obtaining this info can be used as the > fallback when the ethtool op fails. fair enough... how about this then? (still leaves the logistics question between when WARN() hits the tree and when this patch go) 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 | 34 +++++++++++++++++++++++++++++++--- net/sched/sch_generic.c | 9 +++++---- 3 files changed, 39 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 +4552,36 @@ 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; + + if (ops->get_drvinfo) { + memset(&info, 0, sizeof(info)); + info.cmd = ETHTOOL_GDRVINFO; + ops->get_drvinfo(dev, &info); + strlcpy(buffer, info.driver, len); + if (strlen(info.driver) > 0) + 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); -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org