Re: [PATCH 3/4] net/ice: remove SSE vector path

[Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>]

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On Tue, Aug 26, 2025 at 3:50 PM Bruce Richardson <bruce.richardson@intel.com>
wrote:

> On Tue, Aug 26, 2025 at 02:29:28PM +0500, Khadem Ullah wrote:
> >    Hi Bruce,
> >    Thanks for the feedback!
>
> No problem.
> BTW: Please don't top-post in replying - it's best practice to put
> the reply below the text you are replying to. Thanks.
>
> Ohh, I got it :)
I was trimming the quotes when replying but in top-post format,
I will always try to avoid a top-post reply in future!


> AVX2 was first available in systems starting in 2013, (and AMD systems
> since 2015), so at this point it's been around a long time. The SSE code
> paths in the drivers will only be used by systems which do not have AVX2 on
> them - which should be relatively rare, I hope, at this point. There are no
> features in the SSE driver that are not available in the AVX2 one, so, I'm
> not aware of any reason why one would need to use the SSE code path in a
> deployment of DPDK


Yes, I think all features in SSE do already exist in AVX2 paths.

>
> Even without this patch, there will be no features added to the SSE code
> paths in the drivers. Any new additions would just be to the AVX2 and
> AVX-512 code paths. Even for systems without AVX2, if the SSE path is
> removed the driver will fall-back to the scalar paths, which have far more
> features available in them than the SSE codepaths, which were simplified
> for
> performance reasons.
>
> /Bruce
>
Thanks for the update. I could not exactly get the meaning of fall-back to
the scalar path.
Does that mean that the driver automatically switches to the scalar path ?
which is slower but includes all the necessary features that were
simplified in the AVX2 path.
I believe AVX2 provides an average performance much better for small frame
or packet size (about 14 Gbps).

Please forget the previous email, some mess up with practicing not doing
top-posts.
Hope this will be fine :)
Regards,
Khadem

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