tasklet_kill() ensures that we _yield_ the processor until a remote tasklet is completed. However, this leads to a starvation condition as being at the bottom of the scheduler's runqueue means that anything else is able to run, including all hogs keeping the tasklet occupied.
Signed-off-by: Chris Wilson <[email protected]> Reviewed-by: Mika Kuoppala <[email protected]> --- drivers/gpu/drm/i915/gt/intel_engine.h | 7 ++++++- drivers/gpu/drm/i915/gt/intel_engine_cs.c | 10 +++++----- drivers/gpu/drm/i915/i915_request.c | 2 +- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h index 6606b1dbf3d6..47ee8578e511 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine.h +++ b/drivers/gpu/drm/i915/gt/intel_engine.h @@ -232,7 +232,12 @@ static inline void __intel_engine_reset(struct intel_engine_cs *engine, bool intel_engines_are_idle(struct intel_gt *gt); bool intel_engine_is_idle(struct intel_engine_cs *engine); -void intel_engine_flush_submission(struct intel_engine_cs *engine); + +void __intel_engine_flush_submission(struct intel_engine_cs *engine, bool sync); +static inline void intel_engine_flush_submission(struct intel_engine_cs *engine) +{ + __intel_engine_flush_submission(engine, true); +} void intel_engines_reset_default_submission(struct intel_gt *gt); diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 97ceaf7116e8..bb1c1adad78a 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -1190,17 +1190,13 @@ static bool ring_is_idle(struct intel_engine_cs *engine) return idle; } -void intel_engine_flush_submission(struct intel_engine_cs *engine) +void __intel_engine_flush_submission(struct intel_engine_cs *engine, bool sync) { struct tasklet_struct *t = &engine->execlists.tasklet; if (!t->func) return; - /* Synchronise and wait for the tasklet on another CPU */ - tasklet_kill(t); - - /* Having cancelled the tasklet, ensure that is run */ local_bh_disable(); if (tasklet_trylock(t)) { /* Must wait for any GPU reset in progress. */ @@ -1209,6 +1205,10 @@ void intel_engine_flush_submission(struct intel_engine_cs *engine) tasklet_unlock(t); } local_bh_enable(); + + /* Synchronise and wait for the tasklet on another CPU */ + if (sync) + tasklet_unlock_wait(t); } /** diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 2675c6d70779..45744c3ef7c4 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1825,7 +1825,7 @@ long i915_request_wait(struct i915_request *rq, * for unhappy HW. */ if (i915_request_is_ready(rq)) - intel_engine_flush_submission(rq->engine); + __intel_engine_flush_submission(rq->engine, false); for (;;) { set_current_state(state); -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
