On Thursday 27 May 2010 04:42:23 Len Brown wrote: > Please look over and test this patch set. > (If you test linux-next, you already have it) > > There are a few simple patches, leading up to a new intel_idle driver. > > Note that you can get the patch series as a single patch here: > http://ftp.kernel.org/pub/linux/kernel/people/lenb/idle/patches/2.6.34/idle-test-2.6.34.diff.gz > > or pull from this git branch > git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6.git idle-test > > Both are vs 2.6.34. > > Why is it good to have a native intel_idle driver? > > Basically, we think we can do better than ACPI. Why exactly? Is there any info missing in the ACPI tables? Or is this just to be more independent from OEMs? > Indeed, on my (production level commerically available) Nehalem desktop > the ACPI tables are broken and an ACPI OS idles at 100W. With this > driver the box idles at 85W. What exactly was broken there? IMO this is a step backward. CPUfreq runs rather well on nearly every machine supporting it without tons of static frequency tables in kernel. Even powernow-k8 might get merged into acpi-cpufreq. Intel set up a huge ACPI API for this and now it's not used anymore?!? Will these parts get obsoleted in a future spec? While for C-states there are not that many static entries needed, another drawback could be that OEMs will disable/hide C-states on purpose. Using ACPI table based C-states by default and using intel_idle.enable=1 or similar for workarounds sounds safer. At least as long as the driver is experimental. Does Windows use ACPI C-state info for idle? Thanks, Thomas _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
