Re: [PATCH net-next v3 01/17] asm: simd context helper API

From: Jason A. Donenfeld
Date: Wed Sep 12 2018 - 14:10:59 EST


On Wed, Sep 12, 2018 at 8:14 AM Kevin Easton <kevin@xxxxxxxxxxx> wrote:
> Given that it's always supposed to be used like that, mightn't it be
> better if simd_relax() took a pointer to the context, so the call is
> just
>
> simd_relax(&simd_context);
>
> ?
>
> The inlining means that there won't actually be a pointer dereference in
> the emitted code.
>
> If simd_put() also took a pointer then it could set the context back to
> HAVE_NO_SIMD as well?

That's sort of a neat idea. I guess in this scheme, you'd envision:

simd_context_t simd_context;

simd_get(&simd_context);
simd_relax(&simd_context);
simd_put(&simd_context);

And this way, if simd_context ever becomes a heavier struct, it can be
modified in place rather than returned by value from the function. On
the other hand, it's a little bit more annoying to type and makes it
harder to do declaration and initialization on the same line.