Picture Recording: fix the performance bottleneck in SkDeferredCanvas::isFullFrame
blink skips all pending commands during picture recording if it is drawing an opaque full-frame
geometry or image. This may improve performance for some edge cases. To recognize an opaque
full-frame drawing should be cheap enough. Otherwise, the overhead will offset the improvement.
Unfortunately, data from perf for content_shell on Nexus7 shows that SkDeferredCanvas::isFullFrame
is far from cheap. Table below shows that how much isFullFrame() costs in the whole render process.
benchmark percentage
my local benchmark(draw 1000 sprites) 4.1%
speedReading 2.8%
FishIETank(1000 fishes) 1.5%
GUIMark3 Bitmap 2.0%
By contrast, real recording (SkGPipeCanvas::drawBitmapRectToRect) and real rasterization
(GrDrawTarget::drawRect) cost ~4% and ~6% in the whole render process respectively. Apparently,
SkDeferredCanvas::isFullFrame() is nontrivial.
getDeviceSize() is the main contributor to this hotspot. The change simply save the canvasSize and
reuse it among drawings if it is not a fresh frame. This change cut off ~65% (or improved ~2 times)
of isFullFrame().
telemetry smoothness canvas_tough_test didn't show obvious improvement or regression.
BUG=411166
Committed: https://skia.googlesource.com/skia/+/8e45c3777d886ba3fe239bb549d06b0693692152
R=junov@chromium.org, tomhudson@google.com, reed@google.com
Author: yunchao.he@intel.com
Review URL: https://codereview.chromium.org/545813002
3 files changed
