Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes:
> We set up a dummy ring in order to measure the size we require for our
> breadcrumb emission, so that we don't have to manually count dwords! We
> can pass in the kernel_context to use for this so that if required it is
> known for the breadcrumb emitter, and we can reuse some details from the
> kernel_context to reduce the number of temporaries we have to mock.
>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_engine_cs.c | 47 +++++++++--------------
> 1 file changed, 19 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index b1c7b1ed6149..f6f5e1ec48fc 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -631,13 +631,13 @@ static int engine_setup_common(struct intel_engine_cs *engine)
>
> struct measure_breadcrumb {
> struct i915_request rq;
> - struct intel_timeline timeline;
> struct intel_ring ring;
> u32 cs[1024];
> };
>
> -static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
> +static int measure_breadcrumb_dw(struct intel_context *ce)
> {
> + struct intel_engine_cs *engine = ce->engine;
> struct measure_breadcrumb *frame;
> int dw = -ENOMEM;
>
> @@ -647,39 +647,27 @@ static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
> if (!frame)
> return -ENOMEM;
>
> - if (intel_timeline_init(&frame->timeline,
> - engine->gt,
> - engine->status_page.vma))
> - goto out_frame;
> -
> - mutex_lock(&frame->timeline.mutex);
>From locking a mock to locking an existing context.
But it is a fresh one so I decide not to worry.
Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
> + frame->rq.i915 = engine->i915;
> + frame->rq.engine = engine;
> + frame->rq.context = ce;
> + rcu_assign_pointer(frame->rq.timeline, ce->timeline);
>
> frame->ring.vaddr = frame->cs;
> frame->ring.size = sizeof(frame->cs);
> frame->ring.effective_size = frame->ring.size;
> intel_ring_update_space(&frame->ring);
> -
> - frame->rq.i915 = engine->i915;
> - frame->rq.engine = engine;
> frame->rq.ring = &frame->ring;
> - rcu_assign_pointer(frame->rq.timeline, &frame->timeline);
> -
> - dw = intel_timeline_pin(&frame->timeline);
> - if (dw < 0)
> - goto out_timeline;
>
> + mutex_lock(&ce->timeline->mutex);
> spin_lock_irq(&engine->active.lock);
> +
> dw = engine->emit_fini_breadcrumb(&frame->rq, frame->cs) - frame->cs;
> +
> spin_unlock_irq(&engine->active.lock);
> + mutex_unlock(&ce->timeline->mutex);
>
> GEM_BUG_ON(dw & 1); /* RING_TAIL must be qword aligned */
>
> - intel_timeline_unpin(&frame->timeline);
> -
> -out_timeline:
> - mutex_unlock(&frame->timeline.mutex);
> - intel_timeline_fini(&frame->timeline);
> -out_frame:
> kfree(frame);
> return dw;
> }
> @@ -754,12 +742,6 @@ static int engine_init_common(struct intel_engine_cs *engine)
>
> engine->set_default_submission(engine);
>
> - ret = measure_breadcrumb_dw(engine);
> - if (ret < 0)
> - return ret;
> -
> - engine->emit_fini_breadcrumb_dw = ret;
> -
> /*
> * We may need to do things with the shrinker which
> * require us to immediately switch back to the default
> @@ -772,9 +754,18 @@ static int engine_init_common(struct intel_engine_cs *engine)
> if (IS_ERR(ce))
> return PTR_ERR(ce);
>
> + ret = measure_breadcrumb_dw(ce);
> + if (ret < 0)
> + goto err_context;
> +
> + engine->emit_fini_breadcrumb_dw = ret;
> engine->kernel_context = ce;
>
> return 0;
> +
> +err_context:
> + intel_context_put(ce);
> + return ret;
> }
>
> int intel_engines_init(struct intel_gt *gt)
> --
> 2.25.0
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
