Corin Langosch wrote:
by the way: does it hurt to tune the kernel makefile with options like "-O3 -mmmx -msse -msse2" etc...? why isnt this the default, doesn't it speed up the kernel a lot?
x86-64 uses sse/sse2 for parameter passing and float/double arithmetics by default, so these switches are obsolete. However, I guess there is very little floating point arithmetics in the kernel and prefetch optimization isn't done.
3dnow is deprecated, mmx almost useless. So, it doesn't hurt, it doesn't help.