Re: [11/30/16] webperf group call @ 10AM PST

The record of this week’s call is: 

https://www.w3.org/2016/11/30-webperf-minutes.html <https://www.w3.org/2016/11/30-webperf-minutes.html>

also as text below.

-------------------------------
WebPerf Group Call

30 Nov 2016

See also: IRC log

Attendees

Present
igrigorik, Todd, Shubhie, plh, NicJansma, yoav, xiaoqian
Regrets
Chair
igrigorik
Scribe
igrigorik
Contents

 • Topics
  • update on longtasks
  • Paint Timing API
  • Resource Timing L2
  • Navigation Timing L2
 • Summary of Action Items
 • Summary of Resolutions
update on longtasks

shubhie: we want to ship v1 in M57 (early Jan)

_ one change we made is reporting a list of iframe attributes: name, id, source

_ security review: iterating on feedback, still an open discussion

_ attribution: plan is to show long scripts URLs

_ next steps: we'll update the explainer next week, ptal.

_ implementation: partial implementation in Canary behind experimental flag -- give it a try.

yoav: where are we with the spec?

shubhie: yeah, we'll work on expanding on explainer to cover processing / security, etc.
... AI: everyone to review explainer, we'll discuss how and where to expand on next call

Paint Timing API

Todd: there are lots of scenarios where main thread can cause compositor to run slower -- e.g. combination of webgl/canvas/svg bogs down; or an image decode appears to be done on main thread, but image shows up way later

Shubhie: do we have a sense for how common that is?

Todd: this is probably the long tail..
... we should probably think about this entire process as a two phase process: main thread > compositor

_ this is implementation specific, but at the same time, this is a common pattern for most browsers

yoav: what's the point of providing both.. the developer only cares about the longer time?

Todd/Shubhie: having two provides a good hint for where the problem may be

AI: let's document alternative models on GitHub and iterate there

Yoav: we need to start a thread WICG thread and we can transfer the repo

Resource Timing L2

https://github.com/w3c/resource-timing/pull/80

https://github.com/w3c/resource-timing/pull/81

AI: Todd will review

https://github.com/w3c/resource-timing/pull/79

Todd: agree that we can't specify a MUST because we have different implementations; we can add a note in the spec, as in PR

_ there is a separate issue: we should gather some telemetry.. how often is this used? if we find that everyone relies on this, then perhaps we ought go back and change to MUST

igrigorik: we should also write some tests to figure out interop between existing implementations

AI: update note with a disclaimer, and in parallel we should open an issue to investigate current implementations and use in the wild

https://github.com/w3c/resource-timing/issues/63

Todd: if we want to make a difference between first byte vs header complete vs ... those should be different attributes

_ if we want to break apart first byte, we're better of with different measurements

AI: update to align with receipt of first byte by the HTTP parser
... NT2 ...

Navigation Timing L2

Todd: it's helpful to be able to tell the tests apart; having a prefix would be helpful

plh: we're ok with the idea, but we do have tests that apply to both

_ it's ok to have tests that don't have a version number

Shubhie: do we duplicate tests?

Todd: implementations that don't have NT1 would want those

https://github.com/w3c/navigation-timing/pull/52

scribe: we'll merge the extended diagram, as we want to optimize for those reading the spec
... and, looks like Todd beat us to the punch :)

thanks all!

-------------------------------

Thanks.

-xiaoqian



> On 30 Nov 2016, at 6:12 AM, Ilya Grigorik <igrigorik@google.com> wrote:
> 
> Hangout*: https://hangouts.google.com/hangouts/_/chromium.org/webperf-wg <https://hangouts.google.com/hangouts/_/chromium.org/webperf-wg>
> 
> --- Agenda:
> Resource Timing L2
> Clarify initiatorType: https://github.com/w3c/resource-timing/pull/80 <https://github.com/w3c/resource-timing/pull/80>
> Update timing diagram: https://github.com/w3c/resource-timing/pull/81 <https://github.com/w3c/resource-timing/pull/81>
> Recommendation for add/queue steps: https://github.com/w3c/resource-timing/pull/79 <https://github.com/w3c/resource-timing/pull/79>
> responseStart: https://github.com/w3c/resource-timing/issues/63 <https://github.com/w3c/resource-timing/issues/63>
> Navigation Timing L2
> Update timing diagram: https://github.com/w3c/navigation-timing/pull/52 <https://github.com/w3c/navigation-timing/pull/52>
> Tests status, location in W3C repo, etc
> Send out for wide review?
> Paint Timing API update (panicker@)
> Improve version headers?
> https://github.com/w3c/hr-time/pull/39 <https://github.com/w3c/hr-time/pull/39>
> If there are other topics you'd like to add or discuss.. please reply to this thread! 
> 
> ---
> 
> * please hop on IRC if you're having trouble joining the video chat.