Also, the mark names we specified for Firefox OS are currently only used in our core application, but we plan to expand that to third-party applications as well.
Thanks, Eli Perelman Mozilla On Wed, Jun 24, 2015 at 2:56 PM, Eli Perelman <eperel...@mozilla.com> wrote: > I don't want to derail this thread into other topics, but we should > probably address a few things here. > > Performance markers, while they aren't specific from the spec that they > can't be used as platform indicators, are one of the closest things we have > to being able to use as an indicator. If they shouldn't be used as such, > that should probably more explicit, but having an API for indication would > be helpful. A use case I always come back to deals with painting: Why can't > a UA delay first paint until the application designates itself as visually > loaded? This would help avoid flashes of uninitialized content among other > things. > > But I digress. The reason Firefox OS diverged from the recommended mark > names was that they weren't sufficient in describing the more complex > interactions that are involved in the web-as-OS paradigm. At the time it > seemed that modification of the recommended mark names wasn't viable at the > time, coupled with the inconsistencies and differently-focused definitions, > adopting different metric names is reasonable. They are custom markers > after all. They don't technically need to have special meanings to anyone > outside of Firefox OS. > > That said, the markers have been useful for our analytics and opened up > the ability for richer performance testing of Firefox OS. I just wrote a > blog post today [1] about these challenges. We aggregate the metrics in > dashboards [2] with data gathered from User Timing numbers. > > Overall though, I'm open to any discuss any direction that anyone feels is > beneficial for tooling, platforms, or moving the web forward. > > [1] http://eliperelman.com/performance-testing-firefox-os/ > [2] http://raptor.mozilla.org > > Thanks, > > Eli Perelman > Mozilla > > > On Wed, Jun 24, 2015 at 2:32 PM, Philippe Le Hegaret <p...@w3.org> wrote: > >> On 06/24/2015 05:06 PM, Jonas Sicking wrote: >> >>> I still think that the bigger question isn't what string value to use, >>> but whether it is appropriate to say that certain "mark" names have >>> semantic meaning or not. >>> >>> The way that the spec currently works, from my understanding, is that >>> it says "you can use whatever name of a mark you want. The names have >>> whatever meaning you assign to them. Except if you use names X, Y or >>> Z, those have a very specific meaning and will cause A, B and C to >>> happen.". >>> >> >> I actually don't believe the spec says that it will cause anything >> besides recording the time of the mark. They were more intended to help web >> performance analytics [1] [2]. As such, the developers have been encouraged >> to use them but we made it clear that the user agent does not validate that >> the usage of those marks is correct. >> >> Another way to put this is that it feels weird that we have an API >>> which allows a page to add page-defined marker to a timeline. Except >>> that if you give those marker a specific name, it affects when the UA >>> render the page, which is a functionality completely unrelated to the >>> timeline (other than that both functionalities involve "time"). >>> >> >> It shouldn't affect the UA. If it did, this went beyond the original >> intent. >> >> Imho, we should ask ourselves if those marks have been useful for >> analytics. It seems that the answer from Firefox OS is "no thanks, we made >> our own". >> >> It would be useful to have some measures of usage out there of those >> marks and also get a picture of which analytic tool, if any, is actually >> using them (or if they recommend a different set as well). >> >> Based on that, we could either keep what we have, drop it, or recommend a >> new set of marks for analytics. If we want to go beyond that, ie actually >> provide hints for user agents, that would be a new direction imho. >> >> Philippe >> >> [1] >> https://lists.w3.org/Archives/Public/public-web-perf/2011Jan/0038.html >> [2] >> https://lists.w3.org/Archives/Public/public-web-perf/2011Mar/0003.html >> > >
