[ACPI] Reduce acpi-cpufreq switching latency by 50%

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The acpi-cpufreq driver does a P-state get after a P-state set
to verify whether set went through successfully. This test
is kind of redundant as set goes throught most of the times,
and the test is also expensive as a get of P-states can
take a lot of time (same as a set operation) as it goes
through SMM mode. Effectively, we are doubling the P-state
latency due to this get opertion.

momdule parameter "acpi_pstate_strict" restores orginal paranoia.

http://bugzilla.kernel.org/show_bug.cgi?id=5129

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

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Venkatesh Pallipadi 2005-08-25 15:59:00 -04:00 • committed by Len Brown

parent 60cfff3516

commit d395bf12d1

1 changed files with 36 additions and 21 deletions

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arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c

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