Hello! 2.4.2-ac23 doesn't compile in arch/i386/kernel/setup.c. Somebody has changed CONFIG_TSC to CONFIG_X86_TSC, probably without testing the resulting code. CONFIG_TSC was never defined, so it was an error. However, what we have now is that tsc_disable is declared if CONFIG_X86_TSC is not defined, but is used if it is defined. I think we should be a little more consistent here. Possible solutions: 1) "notsc" should be enabled in the kernels for old processors the the case if they run on a better processor and the user may need to disable TSC (ifndef CONFIG_X86_TSC everywhere in setup.c) 2) "notsc" should be enabled in the kernels for the new processors. It would save few bytes in the kernels for i386, but the code for i686 will function even if "notsc" is used (ifdef CONFIG_X86_TSC everywhere in setup.c) 3) Remove all those silly if[n]defs. We have the "cpu_has_tsc" variable on all platforms. clear_bit() and set_in_cr4() are already used on all processors. It should be safe. Regards, Pavel Roskin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/