Re: [PATCH net-next 00/13] Control action percpu counters allocation by netlink flag

[Vlad Buslov <vladbu@mellanox.com>]

On Fri 25 Oct 2019 at 18:43, Jamal Hadi Salim <jhs@mojatatu.com> wrote:
> On 2019-10-25 11:18 a.m., Vlad Buslov wrote:
>>
>
>> The problem with this approach is that it only works when actions are
>> created through act API, and not when they are created together with
>> filter by cls API which doesn't expect or parse TCA_ROOT. That is why I
>> wanted to have something in tcf_action_init_1() which is called by both
>> of them.
>>
>
> Aha. So the call path for tcf_action_init_1() via cls_api also needs
> to have this infra. I think i understand better what you wanted
> to do earlier with changing those enums.
>
> This is fixable - we just need to have the classifier side also take a
> new action root flags bitfield (I can send a sample). To your original

Trying to add this infra to cls API leads back to my original question:
how do I do it in backward compatible manner? I assume that we can't
break users of RTM_NEWTFILTER.

> comment, it is ugly. But maybe "fixing it" is pushing the boundaries
> and we should just go on and let your original approach in.
> My only worry is, given this is uapi, if we go back to your original
> idea we continue to propagate the bad design and we cant take it back
> (all the tooling etc would be cast for the next 5 years even if we
> did fix it in a month). Thoughts?

I don't see anything particularly ugly with extending either
action-specific attributes or TCA_ACT_* attributes, so its hard for me
to reason about problems with current approach :)

>
> cheers,
> jamal