Hello,
CPPC cpufreq driver is used for ARM servers and this patch series tries
to provide counter-based frequency invariance support for them in the
absence for architecture specific counters (like AMUs).
This is tested by:
- /me with some hacks on Hikey, as I didn't have access to the right
hardware.
- Vincent Guittot on ThunderX2, only initial testing done.
- Ionela Voinescu on Juno R2, though she tested a previous version of
this.
This is based of 5.12-rc1.
Changes since V4:
- Move some code to policy specific initialization for cppc driver.
- Initialize kthread specific stuff only once in cppc driver.
- Added a kerneldoc comment in cppc driver and improved changelog as
well.
Changes since V3:
- rebuild_sched_domains_energy() stuff moved from arm64 to drivers/base.
- Added Reviewed/Tested-by Ionela for the first patch.
- Remove unused max_freq field from structure in cppc driver.
- s/cppc_f_i/cppc_freq_inv.
- Fix an per-cpu access, there was a bug in earlier version.
- Create a single kthread which can run on any CPU and takes care of
work from all the CPUs.
- Do the whole FIE thing under a new CONFIG option for cppc driver.
- Few minor improvements.
Changes since V2:
- Not sending as an RFC anymore.
- Several renames, reordering of code in 1/2 based on Ionela's comments.
- Several rebase changes for 2/2.
- The freq_scale calculations are optimized a bit.
- Better overall commenting and commit logs.
Changes since V1:
- The interface for setting the callbacks is improved, so different
parts looking to provide their callbacks don't need to think about
each other.
- Moved to per-cpu storage for storing the callback related data, AMU
counters have higher priority with this.
--
viresh
Viresh Kumar (2):
topology: Allow multiple entities to provide sched_freq_tick()
callback
cpufreq: CPPC: Add support for frequency invariance
arch/arm64/include/asm/topology.h | 10 +-
arch/arm64/kernel/topology.c | 105 +++++--------
drivers/base/arch_topology.c | 85 ++++++++++-
drivers/cpufreq/Kconfig.arm | 9 ++
drivers/cpufreq/cppc_cpufreq.c | 244 ++++++++++++++++++++++++++++--
include/linux/arch_topology.h | 15 +-
kernel/sched/core.c | 1 +
7 files changed, 377 insertions(+), 92 deletions(-)
base-commit: fe07bfda2fb9cdef8a4d4008a409bb02f35f1bd8
--
2.25.0.rc1.19.g042ed3e048af
