[PATCH V2 0/2] cpufreq: ondemand: add AMD specific powersave bias

Jacob Shin
2013-03-28T18:24:25Z

This patchset adds AMD specific powersave bias function to the ondemand
governor; which can be used to help ondemand governor make more power conscious
frequency change decisions based on feedback from hardware (availble on AMD
Family 16h and above).

Hardware feedback tells software how "sensitive" to frequency changes the
workloads are. CPU-bound workloads will be more sensitive -- they will
perform better as frequency increases. Memory/IO-bound workloads will be less
sensitive -- they will not necessarily perform better as frequnecy increases.

This patchset was compared against ondemand governor without powersave bias
and did not show any performance degradation on CPU-bound workloads such as
kernbench and unixbench. While saving power on Memory-bound workloads such as
stream.

This applies to linux-pm's linux-next branch, on top of Viresh's 'Implement
per policy instance of governor' V4 patchset:

https://lkml.org/lkml/2013/3/27/348

V2:
* Added proper include files to amd_freq_sensitivity.c
* Only register powersave_bias_target function pointer and not the entire
od_ops.

Jacob Shin (2):
cpufreq: ondemand: allow custom powersave_bias_target function to be
registered
cpufreq: AMD "frequency sensitivity feedback" powersave bias for
ondemand governor

arch/x86/include/uapi/asm/msr-index.h | 1 +
drivers/cpufreq/Kconfig.x86 | 10 +++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/amd_freq_sensitivity.c | 147 ++++++++++++++++++++++++++++++++
drivers/cpufreq/cpufreq_governor.h | 3 +
drivers/cpufreq/cpufreq_ondemand.c | 22 ++++-
6 files changed, 181 insertions(+), 3 deletions(-)
create mode 100644 drivers/cpufreq/amd_freq_sensitivity.c

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1.7.9.5