On Mon, 2018-01-15 at 08:47 +0000, Chris Wilson wrote: > Watching a light workload on Baytrail (running glxgears and a 1080p > decode), instead of the system remaining at low frequency, the glxgears > would regularly trigger waitboosting after which it would have to spend > a few seconds throttling back down. In this case, the waitboosting is > counter productive as the minimal wait for glxgears doesn't prevent it > from functioning correctly and delivering frames on time. In this case, > glxgears happens to almost always be waiting on the current request, > which we already expect to complete quickly (see i915_spin_request) and > so avoiding the waitboost on the active request and spinning instead > provides the best latency without overcommitting to upclocking. > However, if the system falls behind we still force the waitboost. > Similarly, we will also trigger upclocking if we detect the system is > not delivering frames on time - again using a mechanism that tries to > detect a miss and not preemptively upclock. > > v2: Also skip boosting for after missed vblank if the desired request is > already active. > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > Cc: Radoslaw Szwichtenberg <radoslaw.szwichtenberg@xxxxxxxxx> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
