On Wed, 27 Jul 2005, Steven J. Magnani wrote:
I have been looking into some thermal shutdown issues with our board, and discovered that LinuxBIOS is not enabling the P4's ability to throttle back when the internal sensors indicate that the processor is getting too hot.
yes, this is purposeful. We let linux do that here. It is a bad deal if 1 node of 1022 decides to slow down.
We do this type of thing in Linux. See the LLNL p4therm module for a piece of kernel code that can let you talk to the hardware.
I think Intel's emphasis on having the BIOS do this kind of thing is a real mistake.
It would be relatively easy to implement support for "TM1" thermal control, since that's just setting a MSR bit if the proper CPUID flag is set. "TM2" control would be a little more complicated, since there is the added ability to control the operating frequency and voltage when the processor trips into thermal management mode.
It's easy, and the kernel (directed by a user-mode program) should do it.
ron