On Wed, Jan 17, 2018 at 03:06:57PM -0800, Florian Fainelli wrote:
> From: David Decotigny <de...@googlers.com>
>
> Expose the number of times the link has been going UP or DOWN, and
> update the "carrier_changes" counter to be the sum of these two events.
> While at it, also update the sysfs-class-net documentation to cover:
> carrier_changes (3.15), count_link_up (4.16) and count_link_down (4.16)
What is the idea to have two separate counters? Can a delta between them
be a bigger than 1?
>
> Signed-off-by: David Decotigny <de...@googlers.com>
> [Florian:
> * rebase
> * add documentation
> * merge carrier_changes with up/down counters]
> Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
> ---
> Documentation/ABI/testing/sysfs-class-net | 24 ++++++++++++++++++++++++
> include/linux/netdevice.h | 6 ++++--
> include/uapi/linux/if_link.h | 2 ++
> net/core/net-sysfs.c | 23 ++++++++++++++++++++++-
> net/core/rtnetlink.c | 13 +++++++++++--
> net/sched/sch_generic.c | 4 ++--
> 6 files changed, 65 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-net
> b/Documentation/ABI/testing/sysfs-class-net
> index 6856da99b6f7..e4b0d5157305 100644
> --- a/Documentation/ABI/testing/sysfs-class-net
> +++ b/Documentation/ABI/testing/sysfs-class-net
> @@ -259,3 +259,27 @@ Contact: netdev@vger.kernel.org
> Description:
> Symbolic link to the PHY device this network device is attached
> to.
> +
> +What: /sys/class/net/<iface/carrier_changes
> +Date: Mar 2014
> +KernelVersion: 3.15
> +Contact: netdev@vger.kernel.org
> +Description:
> + 32-bit unsigned integer counting the number of times the link
> has
> + seen a change from UP to DOWN and vice versa
> +
> +What: /sys/class/net/<iface/count_link_up
> +Date: Jan 2018
> +KernelVersion: 4.16
> +Contact: netdev@vger.kernel.org
> +Description:
> + 32-bit unsigned integer counting the number of times the link
> has
> + been up
> +
> +What: /sys/class/net/<iface/count_link_down
> +Date: Jan 2018
> +KernelVersion: 4.16
> +Contact: netdev@vger.kernel.org
> +Description:
> + 32-bit unsigned integer counting the number of times the link
> has
> + been down
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index ed0799a12bf2..28f68f7513d0 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1680,8 +1680,6 @@ struct net_device {
> unsigned long base_addr;
> int irq;
>
> - atomic_t carrier_changes;
> -
> /*
> * Some hardware also needs these fields (state,dev_list,
> * napi_list,unreg_list,close_list) but they are not
> @@ -1719,6 +1717,10 @@ struct net_device {
> atomic_long_t tx_dropped;
> atomic_long_t rx_nohandler;
>
> + /* Stats to monitor link on/off, flapping */
> + atomic_t count_link_up;
> + atomic_t count_link_down;
> +
> #ifdef CONFIG_WIRELESS_EXT
> const struct iw_handler_def *wireless_handlers;
> struct iw_public_data *wireless_data;
> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
> index f8f04fed6186..6e44b0674ba4 100644
> --- a/include/uapi/linux/if_link.h
> +++ b/include/uapi/linux/if_link.h
> @@ -161,6 +161,8 @@ enum {
> IFLA_EVENT,
> IFLA_NEW_NETNSID,
> IFLA_IF_NETNSID,
> + IFLA_COUNT_LINK_UP,
> + IFLA_COUNT_LINK_DOWN,
> __IFLA_MAX
> };
>
> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 7bf8b85ade16..9f732c3dc2ce 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -295,10 +295,29 @@ static ssize_t carrier_changes_show(struct device *dev,
> struct net_device *netdev = to_net_dev(dev);
>
> return sprintf(buf, fmt_dec,
> - atomic_read(&netdev->carrier_changes));
> + atomic_read(&netdev->count_link_up) +
> + atomic_read(&netdev->count_link_down));
> }
> static DEVICE_ATTR_RO(carrier_changes);
>
> +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 DEVICE_ATTR_RO(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_down);
> +
> /* read-write attributes */
>
> static int change_mtu(struct net_device *dev, unsigned long new_mtu)
> @@ -547,6 +566,8 @@ static struct attribute *net_class_attrs[]
> __ro_after_init = {
> &dev_attr_phys_port_name.attr,
> &dev_attr_phys_switch_id.attr,
> &dev_attr_proto_down.attr,
> + &dev_attr_count_link_up.attr,
> + &dev_attr_count_link_down.attr,
> NULL,
> };
> ATTRIBUTE_GROUPS(net_class);
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 16d644a4f974..68f69a956713 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -990,6 +990,8 @@ static noinline size_t if_nlmsg_size(const struct
> net_device *dev,
> + nla_total_size(4) /* IFLA_NEW_NETNSID */
> + nla_total_size(1) /* IFLA_PROTO_DOWN */
> + nla_total_size(4) /* IFLA_IF_NETNSID */
> + + nla_total_size(4) /* IFLA_COUNT_LINK_UP */
> + + nla_total_size(4) /* IFLA_COUNT_LINK_DOWN */
> + 0;
> }
>
> @@ -1551,8 +1553,13 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
> nla_put_string(skb, IFLA_QDISC, dev->qdisc->ops->id)) ||
> nla_put_ifalias(skb, dev) ||
> nla_put_u32(skb, IFLA_CARRIER_CHANGES,
> - atomic_read(&dev->carrier_changes)) ||
> - nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down))
> + atomic_read(&dev->count_link_up) +
> + atomic_read(&dev->count_link_down)) ||
> + nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down) ||
> + nla_put_u32(skb, IFLA_COUNT_LINK_UP,
> + atomic_read(&dev->count_link_up)) ||
> + nla_put_u32(skb, IFLA_COUNT_LINK_DOWN,
> + atomic_read(&dev->count_link_down)))
> goto nla_put_failure;
>
> if (event != IFLA_EVENT_NONE) {
> @@ -1656,6 +1663,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1]
> = {
> [IFLA_EVENT] = { .type = NLA_U32 },
> [IFLA_GROUP] = { .type = NLA_U32 },
> [IFLA_IF_NETNSID] = { .type = NLA_S32 },
> + [IFLA_COUNT_LINK_UP] = { .type = NLA_U32 },
> + [IFLA_COUNT_LINK_DOWN] = { .type = NLA_U32 },
> };
>
> static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
> diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
> index ef8b4ecde2ac..28941636afa3 100644
> --- a/net/sched/sch_generic.c
> +++ b/net/sched/sch_generic.c
> @@ -510,7 +510,7 @@ 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->carrier_changes);
> + atomic_inc(&dev->count_link_up);
> linkwatch_fire_event(dev);
> if (netif_running(dev))
> __netdev_watchdog_up(dev);
> @@ -529,7 +529,7 @@ 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->carrier_changes);
> + atomic_inc(&dev->count_link_down);
> linkwatch_fire_event(dev);
> }
> }
> --
> 2.14.1
>
