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

Rafael J. Wysocki
2013-04-01T20:43:46Z

On Monday, April 01, 2013 02:38:39 PM Jacob Shin wrote:
> On Fri, Mar 29, 2013 at 08:18:54AM +0530, Viresh Kumar wrote:
> > 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>
> >
>
> Hi Rafael,
>
> If this looks okay to you,
> please commit to linux-next when you get the chance.

OK, I wonder what Boris thinks about it, though.

Boris, could you please have a look at this and let me know what you think?

Rafael

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.