Messages in this thread | | | Subject | [PATCHSET] 0/3 Dynamic cpufreq governor and updates to ACPI P-state driver | Date | Mon, 20 Oct 2003 19:56:07 -0700 | From | "Pallipadi, Venkatesh" <> |
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Hi,
Most of the latest CPUs (laptop CPUs in particular) have feature which enable very low latency P-state transitions (like Enhanced Speedstep Technology-EST). Using this feature, we can have a lightweight in kernel cpufreq governor, to vary CPU frequency depending on the CPU usage. The advantage being low power consumption and also cooler laptops.
Another related change is enhancing the current ACPI P-state driver to handle: EST (and MSR based P-state transitions), make the driver SMP aware and introduce HT coordination in the driver (HT siblings share the same CPU frequency).
The patches that follow this mail addresses the above issues. They are against 2.6-test7 kernel. Many thanks to Dominik for his comments and suggestions.
The patches will work on all laptops with EST technology (Centrino) and also on any other system that supports low latency frequency change.
Reviews/testing of patches are most welcome.
Thanks, -Venkatesh
Patches are split as follows:
Patch 1/3: Changes to ACPI P-state driver, to handle MSR based transitions frequency transitions and make the driver SMP aware.
Patch 2/3: Introduce HT-synchronization in the ACPI P-state Driver, to take care of shared CPU frequency between HT siblings.
Patch 3/3: New dynamic cpufreq driver (called DemandBasedSwitch driver), which periodically monitors CPU usage and changes the CPU frequency based on the demand. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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