Re: [PATCH v2 0/3] RISC-V: ifunced memcpy using new kernel hwprobe interface

[Evan Green <evan@rivosinc.com>]

On Wed, Mar 29, 2023 at 11:20 PM Jeff Law <jeffreyalaw@gmail.com> wrote:
>
>
>
> On 3/29/23 13:45, Palmer Dabbelt wrote:
>
> > It's not in for-next yet, but various patch sets / proposals have been
> > on the lists for a few months and it seems like discussion on the kernel
> > side has pretty much died down.  That's why I was pinging the glibc side
> > of things, if anyone here has comments on the interface then it's time
> > to chime in.  If there's no comments then we're likely to end up with
> > this in the next release (so queue into for-next soon, Linus' master in
> > a month or so).
> Right.  And I've suggested that we at least try to settle on the various
> mem* and str* implementations independently of the kernel->glibc
> interface question.

This works for me. As we talked about off-list, this series cleaves
pretty cleanly. One option would be to take this series now(ish,
whenever the kernel series lands), then cleave off my memcpy and
replace it with Vrull's when it's ready. The hope being that two
incremental improvements go faster than waiting to try and land
everything perfectly all at once.
-Evan

>
> I don't much care how we break down the problem of selecting
> implementations, just that we get started.   That can and probably
> should be happening in parallel with the kernel->glibc API work.
>
> I've got some performance testing to do in this space (primarily of the
> VRULL implementations).  It's just going to take a long time to get the
> data.  And that implementation probably needs some revamping after all
> the work on the mem* and str* infrastructure that landed earlier this year.
>
> jeff