drm/i915/pmu: Suspend sampling when GPU is idle
authorTvrtko Ursulin <tvrtko.ursulin@intel.com>
Tue, 21 Nov 2017 18:18:46 +0000 (18:18 +0000)
committerTvrtko Ursulin <tvrtko.ursulin@intel.com>
Wed, 22 Nov 2017 11:25:00 +0000 (11:25 +0000)
commitfeff0dc6cdc527f8a6fd170d8de7966f56890fc0
treed161e7caedcb4e0b7bbb65159cd1ef417acc8f01
parentb46a33e271ed81bd765c632b972c49d5b44729c7
drm/i915/pmu: Suspend sampling when GPU is idle

If only a subset of events is enabled we can afford to suspend
the sampling timer when the GPU is idle and so save some cycles
and power.

v2: Rebase and limit timer even more.
v3: Rebase.
v4: Rebase.
v5: Skip action if perf PMU failed to register.
v6: Checkpatch cleanup.
v7:
 * Add a common helper to start the timer if needed. (Chris Wilson)
 * Add comment explaining bitwise logic in pmu_needs_timer.
v8: Fix some comments styles. (Chris Wilson)
v9: Rebase.
v10: Move function declarations to i915_pmu.h.
v11: Rename functions to i915_pmu_gt_(un)parked. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171121181852.16128-3-tvrtko.ursulin@linux.intel.com
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/i915/i915_gem_request.c
drivers/gpu/drm/i915/i915_pmu.c
drivers/gpu/drm/i915/i915_pmu.h