WebKit Bugzilla
New
Browse
Log In
×
Sign in with GitHub
or
Remember my login
Create Account
·
Forgot Password
Forgotten password account recovery
RESOLVED INVALID
184499
MotionMark gives wrong results after spectre mitigations of performance.now()
https://bugs.webkit.org/show_bug.cgi?id=184499
Summary
MotionMark gives wrong results after spectre mitigations of performance.now()
Carlos Alberto Lopez Perez
Reported
2018-04-11 08:00:30 PDT
After spectre mitigations performance.now() not longer a hight resolution timer. This causes that the default settings of motionmark to give wrong results. Motion mark supports 3 methods to measure performance as you can see here at the bottom right
http://browserbench.org/MotionMark/developer.html
The default should be changed from performance.now() to one of the other methods.
Attachments
Add attachment
proposed patch, testcase, etc.
Simon Fraser (smfr)
Comment 1
2018-04-11 09:21:24 PDT
perf.now() and rAF timestamp should be quantized the same way, and I think Date.now() will also be.
Carlos Alberto Lopez Perez
Comment 2
2018-04-11 16:22:50 PDT
(In reply to Simon Fraser (smfr) from
comment #1
)
> perf.now() and rAF timestamp should be quantized the same way, and I think > Date.now() will also be.
That makes sense, actually. I have been testing motionmark with WPE trunk and I have been getting sometimes some weird results with the default settings (like 1 points on some tests with a +-3000% percent of variance). So, at first I thought it could be related to the spectre mitigations of performance.now() because I couldn't reproduce with the other methods of the benchmark like rAF. But I'm not able to reproduce this with a webkit build of last trunk on Mac. So it should be something else... I'm closing this as invalid, then. Thanks for the comments.
Note
You need to
log in
before you can comment on or make changes to this bug.
Top of Page
Format For Printing
XML
Clone This Bug