IRC log of webperf on 2017-05-31
Timestamps are in UTC.
- 17:03:36 [RRSAgent]
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- logging to http://www.w3.org/2017/05/31-webperf-irc
- 17:03:43 [Zakim]
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- 17:07:02 [igrigorik]
- f2f: June 20 LGTM from everyone
- 17:07:12 [igrigorik]
- we have attendance from Mozilla, Chrome, Apple, Edge.
- 17:07:30 [igrigorik]
- we have a room booked for 16 people
- 17:07:52 [igrigorik]
- AI: Yoav to add link with directions
- 17:08:33 [igrigorik]
- 9-4AM on 20th
- 17:10:41 [igrigorik]
- Agenda: let's allocate an hour or two for key issues, and then focus for the forward looking work.
- 17:11:09 [igrigorik]
- Yoav: it'll be good to have repo owners triage issues ahead of time.
- 17:12:20 [igrigorik]
- let's work on the agenda and review on the 14th
- 17:12:42 [igrigorik]
- AI: call on the 14th
- 17:14:46 [igrigorik]
- next up: enhanced Element proposal
- 17:14:55 [igrigorik]
- cathiechen: https://discourse.wicg.io/t/proposal-enhance-heroelement/2163
- 17:17:27 [igrigorik]
- ... element priority could be a hint to the browser to optimize rendering
- 17:20:34 [igrigorik]
- Shubhie: we should probably treat hero, priority, and callbacks as different requirements
- 17:20:48 [igrigorik]
- ... a page should probably have just a few hero elements
- 17:21:02 [igrigorik]
- ... the prioritization system feels like a separate thing
- 17:21:12 [igrigorik]
- ... the browser should try to prioritize hero elements
- 17:21:41 [igrigorik]
- Yoav: agree, prioritization is something we need to tackle and it should probably be a separate concern
- 17:22:29 [igrigorik]
- Yoav: there is rendering vs resource priorities
- 17:23:57 [igrigorik]
- n8s: not sure if we want hero element to be treated differently
- 17:24:23 [igrigorik]
- ... prioritization is separate; we mostly want metrics for those elements
- 17:24:39 [igrigorik]
- nic: for RUM it's a great way to identify which elements should be measured
- 17:25:24 [smaug]
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- 17:26:14 [igrigorik]
- todd: callbacks is another issue, we're hesitant to expose more of these
- 17:26:28 [igrigorik]
- Shubhie: what's the value of callbacks?
- 17:27:16 [igrigorik]
- ... other than measurement, which we already tackle
- 17:29:41 [igrigorik]
- Cathie: we use callbacks to know when element is paitned, so we can switch (web)views
- 17:29:51 [igrigorik]
- todd: we've had requests like this for Edge
- 17:30:20 [igrigorik]
- ... implementing callbacks like this is probably not the best place in Hero Element
- 17:30:38 [igrigorik]
- ... there is a use case here, but its unclear if callbacks on elements is the correct solution
- 17:31:24 [igrigorik]
- ... the hard part about elements, is that if browser is well optimized, because we may never even layout something out of view.. let alone paint
- 17:31:48 [igrigorik]
- ... the entire idea of the use case doesn't match the processing model -- it does match how some browsers operate
- 17:32:29 [igrigorik]
- AI's: cathie to followup on WICG
- 17:32:44 [igrigorik]
- ... on how to identify hero elements
- 17:34:37 [igrigorik]
- next up: Long Tasks
- 17:34:55 [igrigorik]
- nic: we have beta plugin of boomerang collecting LT data
- 17:35:10 [igrigorik]
- ... using for attribution and signal as time to interactive
- 17:35:41 [igrigorik]
- ... using alongside raF powered frame-rate (not ideal but still useful)
- 17:36:05 [igrigorik]
- ... really impressed with how well it's giving us attribution into delays of page load process
- 17:36:41 [igrigorik]
- ... e.g. container-id is a pretty good signal that allows you to bucket for identifying culprits -- e.g. social widgets, ads, other scripts
- 17:37:20 [igrigorik]
- ... there are a lot of cases where large chunks we can't identify, maybe there's some opportunities for improvement there
- 17:37:42 [igrigorik]
- ... overall, very actionable data and we're very enthusiastic about it
- 17:38:01 [igrigorik]
- ... attribution is key
- 17:38:17 [igrigorik]
- shubhie: also, Nic has a polyfill for time-to-interactive
- 17:38:50 [igrigorik]
- nic: our customers are very enthusiastic about moving away from onload and more towards "when is page interactive" metrics
- 17:39:25 [igrigorik]
- ... we're currently doing something similar to LH and WPT for measuring time to interactive; long tasks looks to be a pretty good signal.
- 17:41:26 [igrigorik]
- ... heuristic: combination of load time of hero images, followed by monitoring long-tasks, rAf powered frame rate, and polling for setTimeout (to detect stalls).. checking that it doesn't happen for 1s
- 17:42:11 [igrigorik]
- todd: large chunks of idle time are not necessarily.. necessary for a good experience; current heuristics don't capture that
- 17:42:39 [igrigorik]
- .. the core problem is when browser is ready to process input
- 17:42:55 [igrigorik]
- shubhie: but input can trigger your rendering pipeline, etc.
- 17:43:29 [igrigorik]
- todd: long task can block input, but 3 back-to-back LT's can allow for input to be interleaved
- 17:44:22 [igrigorik]
- shubhie: right, we have different metrics.. e.g. time-to-consistently-interactive vs more optimistic interactive window
- 17:44:54 [igrigorik]
- todd: how do we measure interactivity? there is probably an opportunity to have some standardization here
- 17:45:10 [igrigorik]
- igrigorik: let's move this to F2F.
- 17:45:40 [igrigorik]
- shubhie: we're starting to think about long-tasks v2.. input welcome.
- 17:46:06 [igrigorik]
- next up Preload
- 17:46:34 [igrigorik]
- yoav: there is a bunch of HTML and Fetch integrations in progress
- 17:46:53 [igrigorik]
- ... landed big update in Fetch to use "potential destination"
- 17:47:50 [igrigorik]
- ... Domenic is working on adding a hook for adding processing model into HTML spec
- 17:48:05 [igrigorik]
- ... the processing logic will live in HTML spec
- 17:48:27 [igrigorik]
- ... similar to this, working on moving 'as' attribute into HTML spec
- 17:48:58 [igrigorik]
- ... last but not least, need to define "preload cache"
- 17:49:17 [igrigorik]
- ... FF is implementing preload and WPT tests are failing because they have a different model for caching
- 17:50:13 [igrigorik]
- ... we're starting to hit observable differences when it comes to preload implementation
- 17:50:44 [igrigorik]
- ... we need to define that under a single processing model in Fetch
- 17:51:51 [igrigorik]
- Blink update: pending i2s for empty-as as an error
- 17:52:02 [igrigorik]
- ... 1LGTM, waiting for more feedback
- 17:52:12 [igrigorik]
- ... also planning to implement in webkit
- 17:53:09 [igrigorik]
- https://github.com/w3c/performance-timeline/issues/77
- 17:53:55 [igrigorik]
- Shubhie: this came up when we told folks to try PaintTiming
- 17:54:10 [igrigorik]
- Charles: could you provide "*" for I want everything?
- 17:54:23 [igrigorik]
- ... that doesn't tell you if something is not supported
- 17:54:41 [igrigorik]
- Yoav: we have feature detection covered
- 17:56:19 [igrigorik]
- ~polyfill: https://github.com/w3c/performance-timeline/issues/77#issuecomment-305068588
- 17:56:28 [igrigorik]
- todd: what if the types are constructable?
- 17:57:27 [igrigorik]
- ... it feels like .getSupportedTypes might be a good convenience feature
- 17:58:20 [igrigorik]
- yoav: what's the difference from 'as'?
- 18:01:00 [igrigorik]
- igrigorik: let's take this to the list to discuss
- 18:01:07 [igrigorik]
- next call June 14 @ 10am -- our usual slot.
- 18:02:10 [xiaoqian]
- present+ igrigorik, n8s, nolanlawson, shubie, yoav, todd, charles, nic, cathiechen
- 18:02:16 [xiaoqian]
- present+ xiaoqian
- 18:02:22 [xiaoqian]
- chair: igrigorik
- 18:02:26 [xiaoqian]
- scribe: igrigorik
- 18:02:30 [xiaoqian]
- RRSAgent, make minutes
- 18:02:30 [RRSAgent]
- I have made the request to generate http://www.w3.org/2017/05/31-webperf-minutes.html xiaoqian
- 18:02:34 [xiaoqian]
- RRSAgent, make log public
- 18:03:29 [xiaoqian]
- meeting: WebPerf Weekly Call
- 18:03:34 [xiaoqian]
- RRSAgent, make minutes
- 18:03:34 [RRSAgent]
- I have made the request to generate http://www.w3.org/2017/05/31-webperf-minutes.html xiaoqian
- 18:27:54 [yoav_]
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