| Message ID | 20191003210100.22250-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/5] drm/i915/execlists: Skip redundant resubmission | expand |
On 03/10/2019 22:00, Chris Wilson wrote: > If we unwind the active requests, and on resubmission discover that we > intend to preempt the active context with itself, simply skip the ELSP > submission. > > Signed-off-by: Chris Wilson <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 @@ 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); > } > } > A little bit of tracepoint noise with in/out but looks correct after I read the new code. And I wonder if trace.pl still works after last couple months of refactors.. :) Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
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 @@ 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); } }
If we unwind the active requests, and on resubmission discover that we intend to preempt the active context with itself, simply skip the ELSP submission. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/gt/intel_lrc.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)