1113781 - MOZ_DUMP_PAINTING builds incur FLB_LOG_PAINTED_LAYER_DECISION string formatting overhead even if we're not going to dump the layer tree

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Markus Stange [:mstange]]

FLB_LOG_PAINTED_LAYER_DECISION is behind an #ifdef MOZ_DUMP_PAINTING, but it doesn't know whether we're actually going to make use of all the extra debugging data it computes, so it just does its thing unconditionally. This can cause really noticeable slowdowns when there are a lot of display items around.

I guess the problem is that FrameLayerBuilder doesn't know whether Layer::Dump is going to be called in the future. Maybe we should add a separate pref that guards FLB_LOG_PAINTED_LAYER_DECISION?

Comment 1

[Benoit Girard (:BenWa)]

Since we're going to make display-list working without MOZ_DUMP_PAINTING, maybe we should make sure this is now behind MOZ_DUMP_PAINTING after this happens.

Comment 2

[Benoit Girard (:BenWa)]

Attachment: patch

This will still print an empty Info: line. Probably not a big deal.

Comment 3

[Benoit Girard (:BenWa)]

Attachment: Only track layer decision with MOZ_DUMP_PAINTING and add a preference. r=mstange

Comment 4

[Benoit Girard (:BenWa)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/be2eca32172a

Comment 5

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/be2eca32172a