epoll, LSB (was: Re: Problem roundup)

[Mike Hearn]

On Sat, 2004-11-20 at 21:33 +0200, Shachar Shemesh wrote:
> No, that's not what optimizing does. The instruction set of all CPUs 
> since 386 is virtually identical, and since 486 is almost completely 
> identical. HOWEVER, different internal CPU structure means that the CPUs 
> progressively approach the RISC architecture.
> 
> One of the characteristics of the RISC architecture is that the compiler 
> is very aware of internal CPU structures, pipeline lengths and bubbles. 
> When you switch on i686 optimization, actual produced instructions would 
> probably not differ much. What would differ is the order in which they 
> are produced. Code optimized for 686 would run on 586 (and probably 486 
> as well), but not run as fast.
> 
> I don't know how significant this impact is. Wine is not very CPU 
> intensive. It's just something to keep in mind.

Yep, I'm aware of the scheduling optimizations used on super-scalar
(sp?) processors. My point was that discussions on the Fedora lists
indicated the kernel guys thought scheduling for Athlon would improve
things for that chip and not actually hurt the P4 any, so it made sense
to compile everything as i586 with Athlon scheduling. Athlon is
apparently much more sensitive to compiler scheduling.

> Hmm. Would separating the BiDi code (which is the reason ICU is linked 
> with GDI) into a separate DLL (they way it is on Windows 2000) help? 

Yes I think that'd be good, as long as things didn't crash and burn if
the DLL couldn't be loaded.

> I hate that solution. I've been bitten by overly strict dependencies 
> before. If you require libstdc++5, mark as depending on it. Same goes 
> for libc versions.

Makes sense. RPM should have picked it up automatically, I'm not sure
why it didn't.

thanks -mike

-- 
Mike Hearn <mike at navi.cx>