Rd: [RFC] dl-procinfo and HWCAP_IMPORTANT support for powerpc
Benjamin Herrenschmidt
benh@kernel.crashing.org
Fri Dec 23 02:08:00 GMT 2005
On Thu, 2005-12-22 at 20:13 -0600, Tom Gall wrote:
> Food for thought .. but if there are good reasons for having perfect
> detail as to the processor one is on, why not just send on the PVR and be done
> with it.
Because you may not need the actual revision :) Anyway, the idea of
using a doublet is just something that came to mind while I was typing,
not a properly thought out thing. I still think the micro architecture
should be out of the HWCAP or we'll just overflow the field.
> > I think it was a mistake to add the microarch like POWER4 in there. It
> > should have been a separate entity, possibly the ELF_PLATFORM string.
> > The change was done in a rush but not properly thought out (and that's
> > partially my fault too).
> >
>
> Perhaps we ought to compile the performance impacts one might want to
> consider so we can continue discussions on what all might (and might not)
> be reason to make sure that whatever design we end up with is going to
> fit.
Yes, well, my main worry is running out of HWCAP bits very soon if we
add microarchitectures there. Especially if we start having the embedded
stuff in.
> > In addition, it might be worth using the vdso for some very processor
> > specific things, thus getting the benefit automatically without
> > requiring a different libc. I've been pondering putting implementations
> > of memcpy and spinlocks in there... food for thoughts at this point
> > though.
>
> Personally I think this is good food for thought.... sorta dark chocolate
> in the cubboard ... yearning to be eaten ... :-)
Yah, good idea :)
Ben.
More information about the Libc-alpha
mailing list