From 44d0a9c05bc078aef75229d0750e9c55959caae4 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 3 Oct 2019 22:00:56 +0100 Subject: [PATCH] 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 Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191003210100.22250-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_lrc.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 431d3b8c3371..3cfea1758fd2 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -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); } } -- 2.11.0