2021-01-25 21:26:26

by Jakub Kicinski

Subject: Re: [RFC v3 net-next] net: core: devlink: add 'dropped' stats field for DROP trap action

On Mon, 25 Jan 2021 14:38:56 +0200 Oleksandr Mazur wrote:
> + if (trap_item->action == DEVLINK_TRAP_ACTION_DROP &&
> + devlink->ops->trap_drop_counter_get) {
> + err = devlink->ops->trap_drop_counter_get(devlink,
> + trap_item->trap,
> + &drops);
> + if (err)
> + return err;
> + }

Why only report this counter when action is set to drop?

Thinking about it again - if the action can be changed wouldn't it
be best for the user to actually get a "HW condition hit" counter,
which would increment regardless of SW config (incl. policers)?

Otherwise if admin logs onto the box and temporarily enables a trap
for debug this count would disappear.

2021-01-26 18:38:44

by Oleksandr Mazur

Subject: Re: [RFC v3 net-next] net: core: devlink: add 'dropped' stats field for DROP trap action

On Mon, 25 Jan 2021 14:38:56 +0200 Oleksandr Mazur wrote:
> +???? if (trap_item->action == DEVLINK_TRAP_ACTION_DROP &&
> +???????? devlink->ops->trap_drop_counter_get) {
> +???????????? err = devlink->ops->trap_drop_counter_get(devlink,
> +?????????????????????????????????????????????????????? trap_item->trap,
> +?????????????????????????????????????????????????????? &drops);
> +???????????? if (err)
> +???????????????????? return err;
> +???? }

> Why only report this counter when action is set to drop?

> Thinking about it again - if the action can be changed wouldn't it
> be best for the user to actually get a "HW condition hit" counter,
> which would increment regardless of SW config (incl. policers)?

> Otherwise if admin logs onto the box and temporarily enables a trap
> for debug this count would disappear.

Okay, so should it become like generic HW counter - trap_hw_counter_get?