diff options
| author | John Harrison <John.C.Harrison@Intel.com> | 2022-10-06 14:38:13 -0700 |
|---|---|---|
| committer | John Harrison <John.C.Harrison@Intel.com> | 2022-10-24 12:12:47 -0700 |
| commit | d7a8680ec9fb217987a9569aba1abeed886805f0 (patch) | |
| tree | 01b2f2d113ca39086ca0da4fef8d655ce47a05b1 /drivers/gpu/drm/i915/gt/intel_engine_cs.c | |
| parent | 47daf84a8bfbc0ff7342b75fa2175591b64ef8d7 (diff) | |
drm/i915: Improve long running compute w/a for GuC submission
A workaround was added to the driver to allow compute workloads to run
'forever' by disabling pre-emption on the RCS engine for Gen12.
It is not totally unbound as the heartbeat will kick in eventually
and cause a reset of the hung engine.
However, this does not work well in GuC submission mode. In GuC mode,
the pre-emption timeout is how GuC detects hung contexts and triggers
a per engine reset. Thus, disabling the timeout means also losing all
per engine reset ability. A full GT reset will still occur when the
heartbeat finally expires, but that is a much more destructive and
undesirable mechanism.
The purpose of the workaround is actually to give compute tasks longer
to reach a pre-emption point after a pre-emption request has been
issued. This is necessary because Gen12 does not support mid-thread
pre-emption and compute tasks can have long running threads.
So, rather than disabling the timeout completely, just set it to a
'long' value.
v2: Review feedback from Tvrtko - must hard code the 'long' value
instead of determining it algorithmically. So make it an extra CONFIG
definition. Also, remove the execlist centric comment from the
existing pre-emption timeout CONFIG option given that it applies to
more than just execlists.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221006213813.1563435-5-John.C.Harrison@Intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_engine_cs.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_engine_cs.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 7c5b33ccedd0..3b7d750ad054 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -508,9 +508,14 @@ static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id, engine->props.timeslice_duration_ms = CONFIG_DRM_I915_TIMESLICE_DURATION; - /* Override to uninterruptible for OpenCL workloads. */ + /* + * Mid-thread pre-emption is not available in Gen12. Unfortunately, + * some compute workloads run quite long threads. That means they get + * reset due to not pre-empting in a timely manner. So, bump the + * pre-emption timeout value to be much higher for compute engines. + */ if (GRAPHICS_VER(i915) == 12 && (engine->flags & I915_ENGINE_HAS_RCS_REG_STATE)) - engine->props.preempt_timeout_ms = 0; + engine->props.preempt_timeout_ms = CONFIG_DRM_I915_PREEMPT_TIMEOUT_COMPUTE; /* Cap properties according to any system limits */ #define CLAMP_PROP(field) \ |