Murali Karicheri <m-kariche...@ti.com> writes:
>> $ ethtool $ sudo ./ethtool --show-frame-preemption enp3s0
>> Frame preemption settings for enp3s0:
>> support: supported
>> active: active
>> supported queues: 0xf
>
> I assume this is will be in sync with ethtool -L output which indicates
> how many tx h/w queues present? I mean if there are 8 h/w queues,
> supported queues will show 0xff.
In this approach, the driver builds these bitmasks, so it's responsible
to keep it consistent with the rest of the stuff that's exposed in
ethtool.
>
>> supported queues: 0xe
> From the command below, it appears this is the preemptible queue mask.
> bit 0 is Q0, bit 1 Q1 and so forth. Right? In that case isn't it more
> clear to display
> preemptible queues : 0xef
>
> In the above Q7 is express queue and Q6-Q0 are preemptible.
In my case, the controller I have here only has 4 queues, and Queue 0 is
the highest priority one, and it's marked as express.
>
> Also there is a handshake called verify that happens which initiated
> by the h/w to check the capability of peer. It looks like
> not all vendor's hardware supports it and good to have it displayed
> something like
>
> Verify supported/{not supported}
>
> If Verify is supported, FPE is enabled only if it succeeds. So may be
> good to show a status of Verify if it is supported something like
> Verify success/Failed
>
>> minimum fragment size: 68
>>
>>
>> $ ethtool --set-frame-preemption enp3s0 fp on min-frag-size 68
>> preemptible-queues-mask 0xe
>>
>> This is a RFC because I wanted to have feedback on some points:
>>
>> - The parameters added are enough for the hardware I have, is it
>> enough in general?
>
> As described above, it would be good to add an optional parameter for
> verify
>
> ethtool --set-frame-preemption enp3s0 fp on min-frag-size 68
> preemptible-queues-mask 0xe verify on
>
The hardware I have do not support this, but this makes sense.
Cheers,
--
Vinicius
