On Tue, 2019-07-23 at 06:01 +1000, David Airlie wrote:
On Tue, Jul 23, 2019 at 5:58 AM Ben Cotton <bcotton(a)redhat.com>
wrote:
> On Mon, Jul 22, 2019 at 3:45 PM Solomon Peachy <pizza(a)shaftnet.org> wrote:
> > But since anectdote != data, are there any sort of deployment numbers
> > out there that show how many Fedora deployments are on AVX[2]-capable
> > hardware?
> >
> There are no stats available that could be considered defensible. At
> best, we could come up with some estimates based on the stats from
> other sources that we might assume have a similar profile as Fedora.
> I'm not sure if that data exists anywhere, though.
>
> My main personal machine also lacks AVX2-capable hardware, so from a
> personal perspective, I'm not super keen on this change. I'm
> privileged enough to be able to upgrade my hardware if required, but I
> recognize that it's not a reasonable request for others.
>
> > > Fedora will use current CPUs more efficiently, increasing performance
> > > and reducing power consumption.
> >
> > I think we need to see some actual benchmarks demonstrating this. For
> > the core kernel and system libraries rather than microbenchmarks or
> > specific applications that already sport AVX[2] codepaths.
> >
> I agree. It would be good to see some more specifics about what the
> benefit will be. That's the only way we can decide if it's worth the
> cost.
I think we don't need to bother, there is way too much hardware still
being sold by CPU vendors that don't meet this baseline.
+1. As I wrote on the talk page for this Change I see it as a complete
non-starter. I don't think we need detailed data to just say that a
change which means Fedora won't work on all CPUs made prior to 2013
(and apparently quite a lot made since then) is a complete non-starter.
Dropping i686 is a Change I can get behind, but this one is being
proposed about a decade too early.
(For anyone collecting anecdata, though: of the 5 PCs running Fedora in
this room, I think only one would be AVX2-capable).
--
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net
http://www.happyassassin.net