New issue
Advanced search Search tips

Issue 681861 link

Starred by 4 users

Issue metadata

Status: Available
Owner: ----
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 3
Type: Bug



Sign in to add a comment

1000x degradation in performance if cavas size exceeds 16MP

Reported by karti...@amazon.com, Jan 17 2017

Issue description

Chrome Version       : 55.0.2883.95

Render text into (4096x4096) canvas. Content renders instantly.

Test URL: https://jsfiddle.net/qyL6Lsko/2/

Render text into (4096x4097) canvas. Text is drawn character by character and takes forever to render entire content.

Test URL: https://jsfiddle.net/qyL6Lsko/3/



 

Comment 1 by woxxom@gmail.com, Jan 17 2017

It's even worse here: the threshold is 3 times lower at ~6.5MP (2669x2500 canvas).
Windows 7x64, Chrome 32-bit, full HW acceleration in chrome://gpu, nVidia 750 Ti 2GB.
Cc: flackr@chromium.org schenney@chromium.org
Components: Blink>SVG
Labels: M-55 Needs-Feedback
Looks similar to  Issue 681611 , could you please confirm.

Comment 3 by f...@opera.com, Jan 18 2017

Components: -Blink>SVG Blink>Canvas
Not SVG. I guess what happens is that 4096 -> 4097 transition means the max size of the render target is exceeded, triggering fallback to software rendering.

Comment 4 by karti...@amazon.com, Jan 18 2017

PreferDisplayListOverGpuSizeThreshold is currently set to 8096 * 4096.

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/graphics/ExpensiveCanvasHeuristicParameters.h?sq=package:chromium&rcl=1484745475&l=63

However, this limit was recently increased from 4096 * 4096 as part of 

https://codereview.chromium.org/2625873005

Comment 5 by junov@chromium.org, Jan 23 2017

Owner: junov@chromium.org
Status: Assigned (was: Unconfirmed)
Even with the fallback to software mode, it should not be that slow. There is something strange going on here. Notice how there's a big block of text that gets drawn quickly when this page starts: https://jsfiddle.net/qyL6Lsko/3/  and then it slows down to an excruciatingly slow pace.  I am seeing the CPU take 25ms to draw a single character. That is not normal.
Owner: ----
Status: Available (was: Assigned)

Sign in to add a comment