[RFC PATCH v6 0/9] The power allocator thermal governor

Javi Merino
2014-12-05T19:04:53Z

Hi linux-pm,

The power allocator governor allocates device power to control
temperature. This requires transforming performance requests into
requested power, which we do with an extended cooling device API
introduced in patch 5 (thermal: extend the cooling device API to
include power information). Patch 6 (thermal: cpu_cooling: implement
the power cooling device API) extends the cpu cooling device using a
simple power model. The division of power between the cooling devices
ensures that power is allocated where it is needed the most, based on
the current workload.

Patches 1-3 adds array printing helpers to ftrace, which we then use
in patch 8.

Changes since v5:
- Addressed Stephen's review of the trace patches.
- Removed power actors and extended the cooling device interface
instead.
- Let platforms override the power allocator governor parameters in
their thermal zone parameters

Changes since v4:
- Add more tracing
- Document some of the limitations of the power allocator governor
- Export the power_actor API and move power_actor.h to include/linux

Changes since v3:
- Use tz->passive to poll faster when the first trip point is hit.
- Don't make a special directory for power_actors
- Add a DT property for sustainable-power
- Simplify the static power interface and pass the current thermal
zone in every power_actor_ops to remove the controversial
enum power_actor_types
- Use locks with the actor_list list
- Use cpufreq_get() to get the frequency of the cpu instead of
using the notifiers.
- Remove the prompt for THERMAL_POWER_ACTOR_CPU when configuring
the kernel

Changes since v2:
- Changed the PI controller into a PID controller
- Added static power to the cpu power model
- tz parameter max_dissipatable_power renamed to sustainable_power
- Register the cpufreq cooling device as part of the
power_cpu_actor registration.

Changes since v1:
- Fixed finding cpufreq cooling devices in cpufreq_frequency_change()
- Replaced the cooling device interface with a separate power actor
API
- Addressed most of Eduardo's comments
- Incorporated ftrace support for bitmask to trace cpumasks

Todo:
- Expose thermal zone parameters in sysfs
- Expose new governor parameters in device tree
- Expose cooling device weights in device tree

Cheers,
Javi & Punit

Dave Martin (1):
tracing: Add array printing helpers

Javi Merino (7):
tools lib traceevent: Generalize numeric argument
tools lib traceevent: Add support for __print_u{8,16,32,64}_array()
thermal: let governors have private data for each thermal zone
thermal: extend the cooling device API to include power information
thermal: cpu_cooling: implement the power cooling device API
thermal: introduce the Power Allocator governor
thermal: add trace events to the power allocator governor

Punit Agrawal (1):
of: thermal: Introduce sustainable power for a thermal zone

.../devicetree/bindings/thermal/thermal.txt | 4 +
Documentation/thermal/cpu-cooling-api.txt | 144 +++++-
Documentation/thermal/power_allocator.txt | 223 +++++++++
drivers/thermal/Kconfig | 15 +
drivers/thermal/Makefile | 1 +
drivers/thermal/cpu_cooling.c | 455 +++++++++++++++++-
drivers/thermal/of-thermal.c | 4 +
drivers/thermal/power_allocator.c | 528 +++++++++++++++++++++
drivers/thermal/thermal_core.c | 128 ++++-
drivers/thermal/thermal_core.h | 8 +
include/linux/cpu_cooling.h | 49 +-
include/linux/ftrace_event.h | 9 +
include/linux/thermal.h | 61 ++-
include/trace/events/thermal_power_allocator.h | 138 ++++++
include/trace/ftrace.h | 17 +
kernel/trace/trace_output.c | 51 ++
tools/lib/traceevent/event-parse.c | 88 +++-
tools/lib/traceevent/event-parse.h | 8 +-
18 files changed, 1886 insertions(+), 45 deletions(-)
create mode 100644 Documentation/thermal/power_allocator.txt
create mode 100644 drivers/thermal/power_allocator.c
create mode 100644 include/trace/events/thermal_power_allocator.h

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1.9.1