compilation of WebGL demo iamnop.com/particles shader slowed 5x, run-time perf dropped to 1/10th
Submitted by nat..@..el.com
Assigned to Intel 3D Bugs Mailing List
Description
Created attachment 125249 ui logs collected from chromebook with --disable-gpu-watchdog
Steps to Reproduce
go to http://www.iamnop.com/particles/ in chrome browser
Expected Result
website should load within 10 seconds with good performance (~30FPS)
Actual Result
Website renders with 0-1FPS. On Skylake/Broadwell it takes ~40 seconds to start rendering. On Brasswell it takes over 2 mins to start rendering.
This looks like performance regression in mesa in later versions(12.0 etc). With mesa 11.30.0 issue is not seen on skylake/broadwell while performance is little better on braswell(cyan) taking ~20 seconds. With mesa ToT issue is always seen.
Tried on above platforms on chromebooks with chromeos and arch linux. Chrome trace indicate BDW with mesa 12.1.0: DoLinkProgram(load stage) wall duration=33.8 seconds BDW with mesa 11.30: DoLinkProgram(load stage) wall duration=6.8 seconds (Good working)
Backporting to mesa 11.3 version on the same target device issue is not seen on big core.
Attachment 125249, "ui logs collected from chromebook with --disable-gpu-watchdog":
ui_logs