On Tue, 2003-09-16 at 22:34, Russell Davie wrote: > I thought linux put the processor into automatic halt when there are no > processes running. > maybe I missed something when configuring to compile the kernel. > this is done in w'doz by inserting Hex EB into PCI register 52
This is a "feature" of the motherboard (the northbridge controller) not the processor. The northbridge (usually listed by lspci as a Host Bridge) can be reconfigured on the fly through its PCI registers (as you know). The command you want is setpci (on Gentoo it is supplied by the pciutils ebuild, YMMV). In your case, setpci -s 00:00.0 52 will show you the current value of register 52. setpci -s 00:00.0 52=EB will set the value. Note 1: Various pci utils have different ways of counting the registers and the hex values within each registers...ie: some will transpose the hex values (BE instead of EB) and some will count register 51 as register 52. Note 2: Turning this feature on can interfere with onboard sound unless a second register bit is also set, this again is northbridge specific and the bit may already be on by default...If you get "crackly" sound you may need to do some more googling for the second register value. As others have noted, this feature has no cooling effect when the CPU is at 100% load. Cheers, Malcolm V. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
