drm/i915/execlists: Skip redundant resubmission

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
This commit is contained in:
Chris Wilson 2019-10-03 22:00:56 +01:00
parent 3032c0b47e
commit 44d0a9c05b

View File

@ -1739,11 +1739,26 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
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);
}
}