16:59:53 <RRSAgent> RRSAgent has joined #webperf
16:59:53 <RRSAgent> logging to http://www.w3.org/2017/08/16-webperf-irc
17:00:41 <igrigorik> hello!
17:00:52 <yoav> hey
17:05:04 <igrigorik> https://docs.google.com/document/d/10dz_7QM5XCNsGeI63R864lF9gFqlqQD37B4q8Q46LMM/edit#
17:06:42 <igrigorik> [hr-time] unload test > Todd will followup w/ Dale
17:07:54 <igrigorik> we can publish CR  once that lands
17:08:01 <igrigorik> [beacon] CORS tests are blocking
17:08:14 <igrigorik> Todd: I'll check-in with Brandon, we should have those tests
17:08:25 <igrigorik> https://github.com/w3c/beacon/issues/41#issuecomment-322365422
17:09:53 <igrigorik> [user-timing] https://github.com/w3c/user-timing/issues/20
17:10:00 <igrigorik> Todd will check-in on status
17:11:18 <igrigorik> one resource per entry test: https://github.com/w3c/web-platform-tests/pull/6567
17:11:36 <igrigorik> yoav: feedback makes sense, we should accumulate the entries, I'll update the test
17:13:50 <igrigorik> Device Memory: propose to adopt officially into WG charter
17:13:55 <igrigorik> Yoav/Todd: sgtm.
17:15:35 <igrigorik> @yoav @xiaoqian will coordinate the move.
17:16:01 <igrigorik> Paint Timing: proposal to adopt into WG
17:16:16 <igrigorik> shubhie: shipped in Chrome, has TAG approval.
17:16:19 <igrigorik> Todd: LGTM
17:16:35 <igrigorik> Yoav: will coordinate the transfer
17:17:03 <igrigorik> Tim: event timing proposal
17:17:10 <igrigorik> https://docs.google.com/presentation/d/1tp3VzgekEfEvymx7eG3ABDoocOZUE7ZsHR3fB44y088/edit
17:17:42 <igrigorik> Tim:  ^ motivation
17:18:35 <igrigorik> ... why not long tasks? LT does not associate al the different top-level-tasks that contribute to a long input event --> goal: this input event caused a long frame
17:19:25 <igrigorik> ... for every DOM event: report handler duration, and if we "drew", time until draw
17:20:04 <igrigorik> ... "drew" is step 4.3 of event loop: "if necessary update the rendering of document..."
17:20:29 <igrigorik> ... if it was necessary use the timestamp when update ran, if not do not provide
17:23:18 <xiaoqian> xiaoqian has joined #webperf
17:23:30 <igrigorik> ... show eventTimestamp and when processing starts and ends (e.g. if event processing was blocked)
17:25:05 <igrigorik> ... we can polyfill much of this, but performance overhead is prohibitive; had to monkey patch addEventListener
17:26:08 <igrigorik> Todd: at first glance, this looks good; some of field names need a more developer friendly name
17:26:33 <igrigorik> ... also worried about linking to rendering but not accounting for off-thread work -- e.g. compositing time, etc.
17:27:23 <igrigorik> ... a lot of partners I see today, are using raF based polyfills
17:27:44 <igrigorik> ... let's say we have this and Long Tasks, are we missing anything?
17:27:53 <igrigorik> Tim: frame display time, probably...
17:28:04 <igrigorik> ... perhaps more associated event data
17:28:16 <igrigorik> Shubhie: we still need slow frames API
17:28:42 <igrigorik> Todd: right, we need to find the right balance on that API; we can't / shouldn't report every frame
17:29:40 <igrigorik> Todd: event duration signals that something got in the way of paint; Long tasks / long frame help explain what happened
17:30:22 <igrigorik> Todd: I like the overall idea and direction here, need to iterate on naming and developer ergonomics
17:30:28 <igrigorik> Shubhie: what about mitigations for rendering?
17:30:56 <igrigorik> Tim: ... we expose if step 4.3 was executed
17:31:26 <igrigorik> ... one possibility is to run 4.3 whenever you hover, not sure if it provides full coverage
17:31:51 <igrigorik> Yoav: how does an analytics provider register for this?
17:32:41 <igrigorik> Tim: you register for all events (e.g. type => "event")
17:32:49 <igrigorik> Yoav: sgtm
17:33:31 <igrigorik> Ilya: do we need to have a conditial 4.3?
17:34:21 <igrigorik> Tim: it may be hard to figure out when to record that timestamp, but probably doable
17:35:37 <igrigorik> ... the question is whether we can "fake" it well enough
17:37:04 <igrigorik> ... I'll do some more thinking on if/how we can do this; the idea is to always report 4.3 and make it indistinguishable
17:37:17 <igrigorik> Yoav: what about changing :visited. Alex Russel had a proposal
17:40:10 <igrigorik> AI's: iterate on developer ergonomics; investigate rendering steps
17:40:25 <igrigorik> ... let's move to WICG to enable feedback and comments
17:40:40 <igrigorik> ... timeline: prototype in ~Q4  in CHrome
17:40:54 <igrigorik> Custom Events: https://docs.google.com/presentation/d/1vGE_6wWNBI7Mm4PHLry0L-Hmu4Mg3xco0vKsb0Zrsoc/edit
17:41:10 <igrigorik> Tim: motivation ^
17:41:32 <igrigorik> ... right now developers are doing pretty gross things with mark and measure -- e.g. encoding data into name string, etc.
17:41:59 <igrigorik> ... arbitrary timestamps is another limitation of UT
17:42:15 <igrigorik> ... e.g. if you want to mark something retroactively, UT does not support
17:42:30 <igrigorik> .. also, want to provide ability to provide custom data
17:42:52 <igrigorik> ... proposal: performance.queueEntry(...)
17:43:21 <igrigorik> ... we could probably extend UT mark vs measure
17:43:28 <igrigorik> s/vs/or
17:43:50 <igrigorik> ... we could expose a constructor, but that's inconsistent with mark/measure
17:43:58 <igrigorik> ... that said, we can make either of those work
17:44:04 <xiaoqian_> xiaoqian_ has joined #webperf
17:44:22 <igrigorik> ... we can get pretty far with a polyfill, but the value here is providing a shared interface for developers + analytics
17:45:50 <igrigorik> ... there may be merit in providing filtering capabilities in v2+, don't think this is strictly required in v1
17:51:27 <igrigorik> Todd / Ilya: filtering is more of a generic PO function, let's separate that from this proposal
17:52:26 <igrigorik> Shubhie: an explicit difference from mark and measure is that you have to provide timestamps
17:53:28 <igrigorik> Todd: need to look at this some more; Nolan wanted arbitrary data and more; the downside is that it requires that you write more JS
17:54:33 <igrigorik> Tim / Todd: mark and measure have some benefits, we should think about how much we can extend and improve them
17:54:48 <igrigorik> ... Tim: we could probably easily build a shim to implement mark and measure on top of this
17:55:45 <igrigorik> Todd: this looks great, just need to iterate on shape and timeline
17:56:12 <igrigorik> ... if you can get this up on WICG, then we can start iterating; I'm very supportive of this, because it provides clear value to the web
17:56:43 <igrigorik> AI: get the spec on WICG
17:58:06 <igrigorik> ... next call: Aug 30.
17:58:56 <xiaoqian_> RRSAgent, make minutes
17:58:56 <RRSAgent> I have made the request to generate http://www.w3.org/2017/08/16-webperf-minutes.html xiaoqian_
17:59:14 <xiaoqian_> RRSAgent, make log public please
17:59:40 <xiaoqian_> zakim, bye
17:59:40 <Zakim> Zakim has left #webperf
17:59:47 <xiaoqian_> RRSAgent, bye
17:59:47 <RRSAgent> I see no action items