diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-28 13:17:13 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-28 22:03:41 +0000 |
| commit | 062444bbc6859dbe9991673ffd377a4af4d76d51 (patch) | |
| tree | 6dfa9be3ece237031f47c7ffc5ae2ffdf70533cd /drivers/gpu/drm/i915/gt/intel_engine_types.h | |
| parent | 1a2695a7465971f28d8c44d6a282b6a2dd91e96f (diff) | |
drm/i915/gt: Expose busywait duration to sysfs
We busywait on an inflight request (one that is currently executing on
HW, and so might complete quickly) prior to setting up an interrupt and
sleeping. The trade off is that we keep an expensive CPU core busy in
order to avoid wake up latency: where that trade off should lie is best
left to the sysadmin.
The busywait mechanism can be compiled out with
./scripts/config --set-val DRM_I915_SPIN_REQUEST 0
The maximum busywait duration can be adjusted per-engine using,
/sys/class/drm/card?/engine/*/ms_busywait_duration_ns
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Steve Carbonari <steven.carbonari@intel.com>
Tested-by: Steve Carbonari <steven.carbonari@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228131716.3243616-4-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_engine_types.h')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_engine_types.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index b23366a81048..80cdde712842 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -547,6 +547,7 @@ struct intel_engine_cs { struct { unsigned long heartbeat_interval_ms; + unsigned long max_busywait_duration_ns; unsigned long preempt_timeout_ms; unsigned long stop_timeout_ms; unsigned long timeslice_duration_ms; |