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Re: MySql broken on older 486 and other cpuid less CPUs. Does this qualify as RC?



On Thu, Apr 05, 2007 at 11:46:16PM +0200, Florian Weimer wrote:
> Document it in the release notes, please.  It's not worth risking
> stability for the majority of users for this kind of bug.
> 
> Anyway, is there any particular reason why upstream (or you) don't use
> the Intel-recommended way for detection of CPUID support?  A library
> twiddling with SIGILL isn't a terribly good idea.

I have no idea.  I just made the smallest change possible to make mysql
not break 486 machines.  The other option is to go back to what was done
for sarge as far as I can tell, which is use the C implementation rather
than the assembly one and loose the performance gains on newer CPUs.

And documenting in the release notes that 486s will break on upgrade
doesn't seem like a particularly good solution without a fixed package
being made.  Well if nothing else it can go into 4.0r1 I guess, or a
proposed update in the mean time.

Now if there is a recomended way to detect cpuid support, then it would
certainly make sense for the upstream to use that instead.  I find the
current method very icky. :)  setjmp, and a SIGILL handler just seems
wrong.  Where does one find the recomended method?

--
Len Sorensen



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