[PATCH 0/2] powercap: idle_inject: Create threads on demand

[Daniel Lezcano]

Idle injection currently registers per-CPU kernel threads during early
initialization, including on CPUs for which no idle injection device
will be registered.

This series makes thread creation follow the lifetime and CPU mask of
each idle injection device.

The first patch adds an optional CPU mask to smpboot thread descriptors.
The mask restricts thread creation, CPU hotplug handling and teardown,
while preserving the existing behavior for descriptors without a mask.

The second patch uses this support to register idle injection threads
when a device registers and destroy them when it unregisters. CPU
ownership claims, registration rollback and thread teardown are
serialized to prevent overlapping registrations from sharing threads.

Validation includes W=1 builds of the affected objects, whitespace
checks and static review of the teardown locking paths. Concurrent
registration and CPU hotplug runtime testing remains outstanding.

The series was tested on Rockchip RK3588.

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Rafael J. Wysocki <rafael at kernel.org>

Daniel Lezcano (2):
  smpboot: Allow restricting per-CPU threads to a CPU mask
  powercap: idle_inject: Create per-CPU threads on registration

 drivers/powercap/idle_inject.c | 69 +++++++++++++++++++++-------------
 include/linux/smpboot.h        |  4 ++
 kernel/smpboot.c               | 17 ++++++++-
 3 files changed, 61 insertions(+), 29 deletions(-)


base-commit: c03c1a14507dfaf8b856c2608f9ac216021fc222
-- 
2.43.0