drm/i915/execlists: Skip redundant resubmission (44d0a9c0) · Commits · 戴 / test

If we unwind the active requests, and on resubmission discover that we intend to preempt the active contexts with themselves, simply skip the ELSP submission. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191003210100.22250-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_lrc.c

+16 −1

Original line number	Diff line number	Diff line
		@@ -1739,11 +1739,26 @@ done:

		if (submit) {
		*port = execlists_schedule_in(last, port - execlists->pending);
		memset(port + 1, 0, (last_port - port) * sizeof(*port));
		execlists->switch_priority_hint =
		switch_prio(engine, *execlists->pending);

		/*
		* Skip if we ended up with exactly the same set of requests,
		* e.g. trying to timeslice a pair of ordered contexts
		*/
		if (!memcmp(execlists->active, execlists->pending,
		(port - execlists->pending + 1) * sizeof(*port))) {
		do
		execlists_schedule_out(fetch_and_zero(port));
		while (port-- != execlists->pending);

		goto skip_submit;
		}

		memset(port + 1, 0, (last_port - port) * sizeof(*port));
		execlists_submit_ports(engine);
		} else {
		skip_submit:
		ring_set_paused(engine, 0);
		}
		}

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