[PATCH v4 0/2] Stop sched tick in idle injection task

From: Jacob Pan
Date: Mon Nov 28 2016 - 16:35:27 EST


Changelog:
v4: - Misc comments from Ingo are addressed, including style fix,
timeout handling, fork().
- Dropped powerclamp patch from this set, move to its own
series.

v3: - Rearrange idle.c change based on Rafael's suggestion.

v2:
- Moved duration timer from powerclamp driver to play_idle()
- Unexport cpuidle_use_deepest_state
- Indentation fix

Idle injection drivers today use RT threads to run idle loop. There are
efficiency and accounting issues with the current intel_powerclamp.c
and acpi_pad.c. A while ago, I posted CFS based idle injection patch trying
to address them:
https://lkml.org/lkml/2015/11/13/576

Peter proposed another approach with the introduction of a PF_IDLE flag.
This patchset is based on his original posting:
https://lkml.org/lkml/2014/6/4/56

These patches apply on top of the kworker and cpu hotplug state machine
changes made to Intel powerclamp driver.
https://lkml.org/lkml/2016/10/17/362

Similar changes to ACPI PAD driver is developed along with other
enhancements. It will be posted after this patchset is accepted.

Jacob Pan (1):
cpuidle: allow setting deepest idle

Peter Zijlstra (1):
idle: add support for tasks that inject idle

drivers/cpuidle/cpuidle.c | 11 +++
include/linux/cpu.h | 2 +
include/linux/cpuidle.h | 4 +-
include/linux/sched.h | 3 +-
kernel/fork.c | 2 +-
kernel/sched/core.c | 1 +
kernel/sched/idle.c | 175 +++++++++++++++++++++++++++++-----------------
7 files changed, 129 insertions(+), 69 deletions(-)

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1.9.1