Hi hpa, First test, the AMD K6-2. Before your patch.. cpu family : 5 model : 8 stepping : 12 After.. cpu family : 5 model : 8 stepping : 4 Line 1826 of setup.c c->x86_mask = tfms & 7; Should be.. c->x86_mask = tfms & 15; I think? Also, look at the feature flags: before: flags : fpu vme de pse tsc msr mce cx8 sep mtrr pge mmx 3dnow after: features : fpu vme de pse tsc msr mce cx8 pge mmx syscall 3dnow Note, I lost MTRR & sep. This may be related to the stepping bug though. I'll recompile a kernel with the &15 fix, and see if that cures all. btw, whilst all this is getting a shakedown, how about renaming that 'x86_mask' field to the more obvious 'x86_stepping' ? c->x86 would make more sense as c->x86_family too thinking about it. regards, Davej. -- | Dave Jones <[EMAIL PROTECTED]> http://www.suse.de/~davej | SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/