AltiVec Kernel Enhancements from MOT

[Tim Seufert]

On Sunday, June 8, 2003, at 02:01  AM, Dorothy over the RGB wrote:

> Using the Sonnet G4 400Mhz upgrade (original L2 removed in both case, 
> the G4
> card comes with its own), I'm getting the same bogus values with or 
> without
> the Sonnet system extension running before launching BootX.

/proc/cpuinfo takes its information about processor clock speed from 
the Open Firwmare device tree.  The Open Firmware revision in the 9500 
and similar Macs is known to have a bug which causes it to always 
report 195 MHz if you install a G3 or G4 upgrade.

Note that the bogomips score is 809.36; for 750 and 7400 CPUs the 
bogomips score should be about 2 times the clock speed.  (Though there 
are cases where it is not; if certain CPU features are disabled the 
ratio may be less than 2.)

Also, since the G4 L2 cache is quite different from the 604e L2 cache, 
it's not reported in the same place.  Try looking at /proc/l2cr, which 
will display the contents of the G3/G4 L2 cache control register.  (Be 
careful about believing the field descriptions for the more esoteric 
settings though; many kernels get them wrong.)