Laine Stump wrote:
> 
> Has anyone experimented with the effects of building the kernel (and
> libc, for that matter) with more agressive options? 1.2 builds with
> simply "-O2". What about making it something like:
> 
>         -O6 -fomit-frame-pointer -m486
> 
> ?? First, does this have a significant impact on system performance, and
> second (the reason I haven't just tried it myself :-) does everything
> still work properly?


I compile all of my kernels (for the past 6 months or so) with the
Pentium version of gcc, with -O3 -fomit-frame-pointer -mpentium 
(aggressive enough for you? :)

I don't know about performance improvements - on userland programs,
similar optimization with pgcc only improves execution time by 5-10%.
File sizes are about 20% smaller, though.  Even smaller with -O2.

I haven't had any problems with pgcc (patch level 9) so far, as long 
as I keep the optimization level at -O2 or -O3.  I have run into 
problems when using -fomit-frame-pointer on some libraries, however.
So I compile everything except the kernel with "pgcc -O2 -mpentium".


Jeff Thieleke