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

Viresh Kumar
2013-03-29T02:48:55Z

On 28 March 2013 23:54, Jacob Shin <jacob.shin@amd.com> wrote:
> 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

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>