[minutes] 2012-02-29 Web Performance WG Teleconference #63

Meeting Summary:



1.      High Resolution Time

a.       Spec submitted

ACTION-69 Create High Resolution Time specification was closed.



b.       Origin

The working group discussed and agreed on having the time base origin tied in with navigationStart.



c.        Resolution

The working group discussed whether the API needed to provide to developers a minimum supported resolution attribute or if we should change the minimum resolution to be even smaller. We decided that unless a compelling use case presents itself, we will stick with a tenth of millisecond as the minimum requirement and allow user agents to exceed that resolution. Further developers can also write code to determine the minimum resolution supported by the user agent.



d.       Security

The working group will follow up on the security section with any feedback if they have some.



2.      JavaScript Timing Proposal

The working group closed on not pursing the JavaScript Timing proposal last week. ACTION-71 Propose use cases for an Instrumentation/Timing API to be used for tooling purposes was closed.



3.      Resource Timing, User Timing and Performance Timeline

a.       High Resolution Time

The specs were updated to include DOMHighResTimeStamp from the High Resolution Time spec. ACTION-63 Inherited objects should return sub-millisecond resolution was closed.



b.       Additional Feedback

The editors will review the list of changes compiled by Philippe to ensure nothing was missed. The changes made in the Last Call period don't seem significant enough to suggest another Last Call.



4.      Page Visibility

a.       Privacy Section

The privacy section was updated to remove UA settings on turning off the API. ACTION-88 Respond to Anne's comment on privacy section for Page Visibility was closed.



b.       Processing Model

The discussion on the processing model text is being worked out on the mailing list. Once this issue is closed, this spec will be ready to move to CR.



5.      requestAnimationFrame

a.       High Resolution Time

There has been a discussion on the mailing list on changing the time base for the time parameter in the requestAnimationFrame callback.




Detailed Notes:



Web Perf Teleconference #63 2/29/2012



IRC log: http://www.w3.org/2012/02/29-webperf-irc


Meeting Minutes: http://www.w3.org/2012/02/29-webperf-minutes.html



Attendees

Present for Navigation Timing, Resource Timing and User Timing (4-5PM EST/1-2PM PST)

Philippe Le Hegaret, Jatinder Mann, Arvind Jain, Alois Reitbauer, James Simonsen, Tony Gentilcore, David Mandelin, Luke Wagner


Present for Page Visibility, Efficient Script Yielding, Display Paint Notifications (4-5PM EST/2-3PM PST)

Meeting cancelled.



Scribe

Jatinder Mann



Contents

Agenda

1.       Feedback on High Resolution Time specification

2.       Feedback on Resource, User and Performance Timeline

3.       Feedback on Page Visibility

4.       Feedback on RequestAnimationFrame


--------------------------------------------------------------------------------
High Resolution Time

Jatinder: Was there any feedback to the spec?

<dmandelin> the users i talked to didn't seem to need to know the resolution, they just wanted to get the best resolution the system could provide

Tony: There was some feedback on the definition of the start of navigation. We should use navigationStart.

Jatinder: I agree that we should tie the definition in with navigationStart.

James: Regarding the minimum resolution, I think we should just leave it as a best effort.

<plh> I'm ok with best effort

Tony: I like it how it is.
... Boris had raised concerns on requestAnimationFrame?

Jatinder: I had responded on the thread. Seeing that developers were aware that they were using prefixed code that could still change behavior and requestAnimationFrame spec has only now just gone into Last Call, I don't think it's too late to make such changes.

Tony: What about performance.timing attributes?

Jatinder: They will remain as is. When using getEntries() you will get the new time.
Resource Timing

Jatinder: http://www.w3.org/2012/02/resource-timing-lc-issues.html

http://lists.w3.org/Archives/Public/public-web-perf/2011Aug/0021.html

plh: Jatinder why don't you review the lists and get back to the mailing list if there are any issues.

Jatinder: Definitely.

Karen: What about mailing list discussions on iframe security?

Tony: We had closed that by saying we were going to use navigationStart.

Jatinder: I wrote a section on statistical fingerprinting. Seeing that cache hits and misses can be determined without sub-millisecond resolution.

James: We should continue the discussion with our security folks and close on this.


Page Visibility

Jatinder: Processing model and privacy section updates have been made.



close action-88

<trackbot> ACTION-88 Respond to Anne's comment on privacy section for Page Visibility closed

closs action-69

close action-69

<trackbot> ACTION-69 Create High Resolution Time specification closed

close action-6

<trackbot> ACTION-6 Investigate https://w3c-test.org/ closed

close action-63

<trackbot> ACTION-63 Inherited objects should return sub-millisecond resolution closed

close action-71

<trackbot> ACTION-71 Propose use cases for an Instrumentation/Timing API to be used for tooling purposes closed