Re: [PATCH net-next RFC v5 04/15] devlink: Add reload actions stats to dev get

From: Jakub Kicinski
Date: Wed Sep 23 2020 - 14:50:13 EST


On Fri, 18 Sep 2020 19:06:40 +0300 Moshe Shemesh wrote:
> Expose devlink reload actions stats to the user through devlink dev
> get command.
>
> Examples:
> $ devlink dev show
> pci/0000:82:00.0:
> stats:
> reload_action_stats:
> driver_reinit 2
> fw_activate 1
> fw_activate_no_reset 0
> remote_driver_reinit 0
> remote_fw_activate 0
> remote_fw_activate_no_reset 0
> pci/0000:82:00.1:
> stats:
> reload_action_stats:
> driver_reinit 0
> fw_activate 0
> fw_activate_no_reset 0
> remote_driver_reinit 1
> remote_fw_activate 1
> remote_fw_activate_no_reset 0
>
> $ devlink dev show -jp
> {
> "dev": {
> "pci/0000:82:00.0": {
> "stats": {
> "reload_action_stats": [ {
> "driver_reinit": 2
> },{
> "fw_activate": 1
> },{
> "fw_activate_no_reset": 0
> },{
> "remote_driver_reinit": 0
> },{
> "remote_fw_activate": 0
> },{
> "remote_fw_activate_no_reset": 0
> } ]
> }
> },
> "pci/0000:82:00.1": {
> "stats": {
> "reload_action_stats": [ {
> "driver_reinit": 0
> },{
> "fw_activate": 0
> },{
> "fw_activate_no_reset": 0
> },{
> "remote_driver_reinit": 1
> },{
> "remote_fw_activate": 1
> },{
> "remote_fw_activate_no_reset": 0
> } ]
> }
> }
> }
> }
>
> Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxxxx>
> ---
> v4 -> v5:
> - Add remote actions stats
> - If devlink reload is not supported, show only remote_stats
> v3 -> v4:
> - Renamed DEVLINK_ATTR_RELOAD_ACTION_CNT to
> DEVLINK_ATTR_RELOAD_ACTION_STAT
> - Add stats per action per limit level
> v2 -> v3:
> - Add reload actions counters instead of supported reload actions
> (reload actions counters are only for supported action so no need for
> both)
> v1 -> v2:
> - Removed DEVLINK_ATTR_RELOAD_DEFAULT_LEVEL
> - Removed DEVLINK_ATTR_RELOAD_LEVELS_INFO
> - Have actions instead of levels
> ---
> include/uapi/linux/devlink.h | 5 +++
> net/core/devlink.c | 70 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 75 insertions(+)
>
> diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
> index 0c5d942dcbd5..648d53be691e 100644
> --- a/include/uapi/linux/devlink.h
> +++ b/include/uapi/linux/devlink.h
> @@ -497,7 +497,12 @@ enum devlink_attr {
> DEVLINK_ATTR_RELOAD_ACTION, /* u8 */
> DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED, /* nested */
> DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL, /* u8 */
> + DEVLINK_ATTR_RELOAD_ACTION_STATS, /* nested */
> + DEVLINK_ATTR_RELOAD_ACTION_STAT, /* nested */
> + DEVLINK_ATTR_RELOAD_ACTION_STAT_REMOTE, /* flag */
> + DEVLINK_ATTR_RELOAD_ACTION_STAT_VALUE, /* u32 */
>
> + DEVLINK_ATTR_DEV_STATS, /* nested */
> /* add new attributes above here, update the policy in devlink.c */

I'd propose this nesting:

[DEV_STATS]
[RELOAD_STATS]
[DEV_STATS_ENTRY]
[ACTION]
[LIMIT]
[VALUE]
[DEV_STATS_ENTRY]
[...]
[REMOTE_RELOAD_STATS]
[DEV_STATS_ENTRY]
[ACTION]
[LIMIT]
[VALUE]
[DEV_STATS_ENTRY]
[...]

Then you can fill in the inside of the [REMOTE_]RELOAD_STATS nests with
a helper, and similarly user space can separate the two in JSON more
cleanly than string concat.

> __DEVLINK_ATTR_MAX,
> diff --git a/net/core/devlink.c b/net/core/devlink.c
> index 1509c2ffb98b..71aeda259e6a 100644
> --- a/net/core/devlink.c
> +++ b/net/core/devlink.c
> @@ -501,10 +501,39 @@ devlink_reload_action_limit_level_is_supported(struct devlink *devlink,
> return test_bit(limit_level, &devlink->ops->supported_reload_action_limit_levels);
> }
>
> +static int devlink_reload_action_stat_put(struct sk_buff *msg, enum devlink_reload_action action,
> + enum devlink_reload_action_limit_level limit_level,
> + bool is_remote, u32 value)
> +{
> + struct nlattr *reload_action_stat;
> +
> + reload_action_stat = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_ACTION_STAT);
> + if (!reload_action_stat)
> + return -EMSGSIZE;
> +
> + if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_ACTION, action))
> + goto nla_put_failure;
> + if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL, limit_level))
> + goto nla_put_failure;
> + if (is_remote && nla_put_flag(msg, DEVLINK_ATTR_RELOAD_ACTION_STAT_REMOTE))
> + goto nla_put_failure;
> + if (nla_put_u32(msg, DEVLINK_ATTR_RELOAD_ACTION_STAT_VALUE, value))
> + goto nla_put_failure;
> + nla_nest_end(msg, reload_action_stat);
> + return 0;
> +
> +nla_put_failure:
> + nla_nest_cancel(msg, reload_action_stat);
> + return -EMSGSIZE;
> +}
> +
> static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
> enum devlink_command cmd, u32 portid,
> u32 seq, int flags)
> {
> + struct nlattr *dev_stats, *reload_action_stats;
> + int i, j, stat_idx;
> + u32 value;
> void *hdr;
>
> hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
> @@ -516,9 +545,50 @@ static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
> if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_FAILED, devlink->reload_failed))
> goto nla_put_failure;
>
> + dev_stats = nla_nest_start(msg, DEVLINK_ATTR_DEV_STATS);
> + if (!dev_stats)
> + goto nla_put_failure;
> + reload_action_stats = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_ACTION_STATS);
> + if (!reload_action_stats)
> + goto dev_stats_nest_cancel;
> +
> + for (j = 0; j <= DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX; j++) {
> + if (!devlink_reload_action_limit_level_is_supported(devlink, j))
> + continue;
> + for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
> + if (!devlink_reload_action_is_supported(devlink, i) ||
> + devlink_reload_combination_is_invalid(i, j))
> + continue;
> +
> + stat_idx = j * __DEVLINK_RELOAD_ACTION_MAX + i;
> + value = devlink->reload_action_stats[stat_idx];
> + if (devlink_reload_action_stat_put(msg, i, j, false, value))
> + goto reload_action_stats_nest_cancel;
> + }
> + }
> +
> + for (j = 0; j <= DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX; j++) {
> + for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
> + if (i == DEVLINK_RELOAD_ACTION_UNSPEC ||
> + devlink_reload_combination_is_invalid(i, j))
> + continue;
> +
> + stat_idx = j * __DEVLINK_RELOAD_ACTION_MAX + i;
> + value = devlink->remote_reload_action_stats[stat_idx];
> + if (devlink_reload_action_stat_put(msg, i, j, true, value))
> + goto reload_action_stats_nest_cancel;
> + }
> + }

This calls for a helper.