[PATCH v3 0/2] power: introduce PM QoS interface

[Huisong Li]

The deeper the idle state, the lower the power consumption, but the longer
the resume time. Some service are delay sensitive and very except the low
resume time, like interrupt packet receiving mode.

And the "/sys/devices/system/cpu/cpuX/power/pm_qos_resume_latency_us" sysfs
interface is used to set and get the resume latency limit on the cpuX for
userspace. Please see the description in kernel document[1].
Each cpuidle governor in Linux select which idle state to enter based on
this CPU resume latency in their idle task.

The per-CPU PM QoS API can be used to control this CPU's idle state
selection and limit just enter the shallowest idle state to low the delay
after sleep by setting strict resume latency (zero value).

[1] https://www.kernel.org/doc/html/latest/admin-guide/abi-testing.html?highlight=pm_qos_resume_latency_us#abi-sys-devices-power-pm-qos-resume-latency-us

---
 v3:
  - add RTE_POWER_xxx prefix for some macro in header
  - add the check for lcore_id with rte_lcore_is_enabled
 v2:
  - use PM QoS on CPU wide to replace the one on system wide

Huisong Li (2):
  power: introduce PM QoS API on CPU wide
  examples/l3fwd-power: add PM QoS configuration

 doc/guides/prog_guide/power_man.rst    |  22 +++++
 doc/guides/rel_notes/release_24_07.rst |   4 +
 examples/l3fwd-power/main.c            |  29 +++++++
 lib/power/meson.build                  |   2 +
 lib/power/rte_power_qos.c              | 114 +++++++++++++++++++++++++
 lib/power/rte_power_qos.h              |  71 +++++++++++++++
 lib/power/version.map                  |   2 +
 7 files changed, 244 insertions(+)
 create mode 100644 lib/power/rte_power_qos.c
 create mode 100644 lib/power/rte_power_qos.h

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2.22.0