Re: [PATCH net-next v5 13/14] libie: add per-queue Page Pool stats

[Alexander Lobakin]

From: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
Date: Thu, 30 Nov 2023 17:01:23 +0100

> From: Jakub Kicinski <kuba@xxxxxxxxxx>
> Date: Wed, 29 Nov 2023 06:29:14 -0800
> 
>> On Wed, 29 Nov 2023 14:40:33 +0100 Alexander Lobakin wrote:
>>>> Expand the libie generic per-queue stats with the generic Page Pool
>>>> stats provided by the API itself, when CONFIG_PAGE_POOL_STATS is
>>>> enabled. When it's not, there'll be no such fields in the stats
>>>> structure, so no space wasted.  
>>>
>>> Do I get it correctly that after Page Pool Netlink introspection was
>>> merged, this commit makes no sense and we shouln't add PP stats to the
>>> drivers private ones?
>>
>> Yes, 100%.
> 
> Meh, this way the stats won't survive ifdown/ifup cycles as usually
> page_pools get destroyed on ifdown :z
> In that patch, I backup the PP stats to a device-lifetime container when
> the pool gets destroyed, maybe we could do something similar?

I still can pull the PP stats to the driver before destroying it, but
there's no way to tell the PP I have some archived stats for it. Maybe
we could have page_pool_params_slow::get_stats() or smth like this?

> 
>>
>> FWIW I am aware that better tooling would be good so non-developers
>> could access to the PP Netlink :(  I'm thinking we should clean up 
>> YNL lib packaging a little and try to convince iproute2 maintainers 
>> to accept simple CLI built on top of it.

Thanks,
Olek