Matthew Miller wrote:
As I've said elsewhere, I think this niche would be better served by a Fedora Lite distribution than by making Fedora Core do it. (In fact, I'd include i586 with that.)
And as others have said before, there are still plenty of K6 and other processors still around (586-instruction-set-compatible, but not fully 686) that are admittedly far from the front line of computing but which are still used in desktop-style situations. (I of course have personal reasons to want to save this class: My girlfriend has a laptop with a K6; admittedly it's seeing a lot less use since I bought a new laptop but it's still nice to have around. I'm planning to put FC2 on it within days, it's our only computer that is still running FC1.) Dumping these without a really good reason would IMHO be a shame. (There's also the class of low-power Via platforms; only the pretty recent C3's have full CMOV and thus older ones don't work with gcc's 686 code. These are also fairly recent and don't IMHO deserve to be tossed on the "unsupported" dumping ground just yet.)
Going to i486 as the minimum,as opposed to sticking with 386, seems very rational, considering Jakub Jelinek's investigations of the feasibility of using NPTL on i386 (apparently a semi-functional hack essentially, which would suck up maintenance resources for minimal gain - and zero gain for any Fedora- or Red Hat-supported configuration) and i486 (it's got the stuff needed to do it sanely) it seems that choosing i486 as a baseline for now has the best pain-to-gain ratio for the time being, especially given the comments heard recently on this mailing list that the 586 really didn't bring much particularly useful to the table in terms of instructions that really speed things up. [Note that the comments on NPTL are meant to essentially be paraphrasing what Jakub Jelinek has said on the subject, I have no sufficient knowledge to add anything on that front - and if I misunderstood that's all my fault.]
Since this would effectively actually _lower_ the bar for using Fedora with marginal modifications (essentially recompile the kernel for i486, as opposed to rpm being broken since it wants to link with NPTL that doesn't currently exist in <586 packages) it should even make a lot of people experimenting with low-end systems happy. Even though it's not a supported feature of Fedora Core, preventing it for minimal gain sounds useless to me.
Of course, at some point it's likely going to make sense to move to i686+CMOV (gcc's 686 definition as far as I understand) as a base level, which is essentially the next sensible higher option available. I absolutely do not think that the time is here yet.
/Per
-- Per Bjornsson <perbj at stanford dot edu> Ph.D. Candidate, Department of Applied Physics, Stanford University
