Is there a way to benchmark general kernel performance?

[Steve Snyder]

I've read varying opinions as to whether this or that compiler option 
will really improve the performance of the Linux (versions 2.2.1x) 
kernel.  This is with egcs v1.1.2.

Does changing the default "-m486" to "-march=i686" really improve the 
code generated?  If I change the default "-O2" to "-O3" will the code 
run faster or just consume more RAM?

Without benchmarking it's all just speculation.   So... is there a 
method for measuring generalized kernel performance?  If not for 
general performance, how about specific features of the kernel?

Thank you.

*** Steve Snyder ***