OpenSolaris

Heads up: Solaris support of Intel Enhanced Speedstep

Date: Mon, 16 Jul 2007 13:43:54 -0400
From: Mark Haywood <Mark.Haywood at Sun dot COM>
To: on-all at eng dot sun dot com, onnv-gate at onnv dot eng dot sun dot com
Subject: Heads up: Solaris support of Intel Enhanced Speedstep

The putback of:

        6512756 Solaris should support Intel's Enhanced Speedstep
        6358066 PSARC/2004/826 Opteron/Athlon64 Frequency Management
        6335616 x86 CPU PwrMgmt needs Notify/_PPC for changes in P-states
                         P-states
        introduces CPU power management capabilities to Solaris x86
        platforms running on a subset of Intel-based systems (currently
        only family 0xF with models >= 0x3 and family 0x6 with models >=
0xE).

        Don't be fooled by the PSARC case title above. The PSARC case
defined
        interfaces that are expected to be used by all x86 CPU power
        management implementations and Intel Enhanced Speedstep is the first
        such implementation. You can determine whether or not your system is
        CPU power management capable, by parsing the output from
        '/usr/bin/kstat cpu_info' and observing whether or not the
        "supported_frequencies_Hz" attribute contains multiple values.
If so,
        then your system is CPU power management capable.

        Note also that the putback of:

        6260724 PSARC/2005/067 CPU Power Management independent of autopm

        back in build 53 introduced two new keywords to power.conf(4),
"cpupm"
        and "cpu-threshold" that can be used to power manage CPUs
independently
        from other devices. As an example, the following power.conf entries
        enable CPU power management and set a CPU idle threshold
irrespective
        of the "autopm" and "system-threshold" settings:

        cpupm           enable
        cpu-thresold    20m

        Questions can be directed to me or to x86power-iteam at sun dot com and
        bugs should be filed under solaris/kernel/pm.