[0/3] thermal/netlink/intel_hfi: Enable HFI feature only when required

Message

Stanislaw Gruszka Jan. 31, 2024, 12:05 p.m. UTC

The patchset introduces a netlink notification, which together with
netlink_has_listners() check, allow drivers to send netlink multicast
events based on the presence of actual user-space consumers.
This functionality optimizes resource usage by allowing disabling
of features when not needed.

Then implement the notification mechanism in the intel_hif driver,
it is utilized to disable the Hardware Feedback Interface (HFI)
dynamically. By implementing a netlink notify callback, the driver
can now enable or disable the HFI based on actual demand, particularly
when user-space applications like intel-speed-select or Intel Low Power
daemon utilize events related to performance and energy efficiency
capabilities.

On machines where Intel HFI is present, but there are no user-space
components installed, we can save tons of CPU cycles.

Stanislaw Gruszka (3):
  netlink: Add notifier when changing netlink socket membership
  thermal: netlink: Export thermal_group_has_listeners()
  thermal: intel: hfi: Enable interface only when required

 drivers/thermal/intel/intel_hfi.c | 82 +++++++++++++++++++++++++++----
 drivers/thermal/thermal_netlink.c |  7 +--
 drivers/thermal/thermal_netlink.h | 11 +++++
 include/linux/notifier.h          |  1 +
 net/netlink/af_netlink.c          |  6 +++
 5 files changed, 92 insertions(+), 15 deletions(-)