Re: [PATCH v1] net-sysfs: expose number of link up/down transitions

[Jiri Pirko <jiri@resnulli.us>]

Fri, Mar 28, 2014 at 05:35:00AM CET, decot@googlers.com wrote:
>Tested:
>  grep . /sys/class/net/*/count_link_*
>  + ip link set dev X down/up
>
>Signed-off-by: David Decotigny <decot@googlers.com>
>---
> include/linux/netdevice.h |  4 ++++
> net/core/net-sysfs.c      | 18 ++++++++++++++++++
> net/sched/sch_generic.c   |  2 ++
> 3 files changed, 24 insertions(+)
>
>diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>index 4b6d12c..cf52869 100644
>--- a/include/linux/netdevice.h
>+++ b/include/linux/netdevice.h
>@@ -1315,6 +1315,10 @@ struct net_device {
> 					     * Do not use this in drivers.
> 					     */
> 
>+	/* Stats to monitor link on/off, flapping */
>+	atomic_t		count_link_up;
>+	atomic_t		count_link_down;
>+
> #ifdef CONFIG_WIRELESS_EXT
> 	/* List of functions to handle Wireless Extensions (instead of ioctl).
> 	 * See <net/iw_handler.h> for details. Jean II */
>diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
>index daed9a6..a65ac54 100644
>--- a/net/core/net-sysfs.c
>+++ b/net/core/net-sysfs.c
>@@ -253,6 +253,22 @@ static ssize_t operstate_show(struct device *dev,
> }
> static DEVICE_ATTR_RO(operstate);
> 
>+static ssize_t count_link_up_show(struct device *dev,
>+				  struct device_attribute *attr, char *buf)
>+{
>+	struct net_device *netdev = to_net_dev(dev);
>+	return sprintf(buf, fmt_dec, atomic_read(&netdev->count_link_up));
>+}
>+
>+static ssize_t count_link_down_show(struct device *dev,
>+				    struct device_attribute *attr, char *buf)
>+{
>+	struct net_device *netdev = to_net_dev(dev);
>+	return sprintf(buf, fmt_dec, atomic_read(&netdev->count_link_down));
>+}
>+static DEVICE_ATTR_RO(count_link_up);
>+static DEVICE_ATTR_RO(count_link_down);
>+


If this is exposed in sysfs, this needs to be exposed via RT netlink as
well.


> /* read-write attributes */
> 
> static int change_mtu(struct net_device *net, unsigned long new_mtu)
>@@ -386,6 +402,8 @@ static struct attribute *net_class_attrs[] = {
> 	&dev_attr_duplex.attr,
> 	&dev_attr_dormant.attr,
> 	&dev_attr_operstate.attr,
>+	&dev_attr_count_link_up.attr,
>+	&dev_attr_count_link_down.attr,
> 	&dev_attr_ifalias.attr,
> 	&dev_attr_carrier.attr,
> 	&dev_attr_mtu.attr,
>diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
>index e82e43b..2d06943 100644
>--- a/net/sched/sch_generic.c
>+++ b/net/sched/sch_generic.c
>@@ -310,6 +310,7 @@ void netif_carrier_on(struct net_device *dev)
> 	if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
> 		if (dev->reg_state == NETREG_UNINITIALIZED)
> 			return;
>+		atomic_inc(&dev->count_link_up);
> 		linkwatch_fire_event(dev);
> 		if (netif_running(dev))
> 			__netdev_watchdog_up(dev);
>@@ -328,6 +329,7 @@ void netif_carrier_off(struct net_device *dev)
> 	if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
> 		if (dev->reg_state == NETREG_UNINITIALIZED)
> 			return;
>+		atomic_inc(&dev->count_link_down);
> 		linkwatch_fire_event(dev);
> 	}
> }
>-- 
>1.9.1.423.g4596e3a
>