On Tue, 9 Aug 2011 08:41:04 -0400 Andy Lutomirski <luto@xxxxxxx> wrote: > Intel allows BIOS or the OS to enable or disable some CPU fueatures via > IA32_MISC_ENABLE. I have machines that don't enable fast strings or > monitor/mwait in BIOS, so do it on bootup instead. The question is - why. > The Intel SDM volume 3, appendix B.1 says that the OS should not touch > the monitor enable bit if SSE3 is not present, which presumably means > that the OS may touch that bit if SSE3 is present. In any case, these > patches seem to work. That's a big "presumes" For example back in Pentium days the BIOS sometimes turned off a string fast path because it was subtly not reliable on certain parts and could corrupt. It's possible your BIOS vendor has a good reason for doing this. It's also possible its a bug, or a left over perhaps from some pre-release processor or something. I think a bit more research is probably appropriate before processor configuration hacks go in that 'seem to work'. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
