Judging from the incoming flow of bug reports, the number of people using the Gecko Profiler has increased in the last week or two. I take this as a good sign that it's being used increasingly heavily for Quantum Flow work, which is good.
Nick On Fri, Apr 21, 2017 at 4:25 PM, Ehsan Akhgari <ehsan.akhg...@gmail.com> wrote: > Hi everyone, > > I would like to share some updates about some of the ongoing performance > related work. > > We have started looking at the native stack traces that are submitted > through telemetry from the Background Hang Reports that take more than 8 > seconds. (We were hoping to have been able to reduce this threshold to > 256ms <https://bugzilla.mozilla.org/show_bug.cgi?id=1346415> for a while > now, but the road has been bumpy -- but this should land really soon now!) > Michael Layzell put together a telemetry analysis job that creates a > symbolicated version of this data here: https://people-mozilla.org/~ > mlayzell/bhr/. For example, this > <https://people-mozilla.org/%7Emlayzell/bhr/20170405.html> is the latest > generated report. The grouping of this data is unfortunate, since the data > is collected based on the profiler pseudo-stack labels, which is captured > after 128ms, and then native stack (if the hang continues for 8 seconds) > gets captured after that, so the pseudo-stack and the native stack may or > may not correspond, and this grouping also doesn't help going through the > list of native stacks and triage them more effectively. Work is under way > to create a nice dashboard > <https://bugzilla.mozilla.org/show_bug.cgi?id=1344003> out of this data, > but in the mean time this is an area where we could really use all of the > help that we can get. If you have some time, it would be really nice if > you can take a look at this data and see if you can make sense of some of > these call stacks and find some useful bug reports out of them. If you do > end up filing bugs, these are super important bugs to work on, so please > make sure you add "[qf]" to the status whiteboard so that we can track the > bug. > > Another item worthy of highlight is Mike Conley's Oh No! Reflow! add-on > <https://mikeconley.github.io/ohnoreflow/>. Don't let the simple web > page behind this link deceive you, this add-on is really awesome! It > generates a beep every time that a long running reflow happens in the > browser UI (which, of course, you get to turn off when you don't need to > hunt for bugs!), and it logs the sync reflows that happened alongside the > JS call stack to the code that triggered them, and it also gives you a > single link that allows you to quickly file a bug with all of the right > info in it, pre-filled! In fact you can see the list of already filed > bugs > <https://bugzilla.mozilla.org/buglist.cgi?quicksearch=sw%3A%22%5Bohnoreflow%5D%22&list_id=13547427> > through this add-on! > > Another issue that I want to bring up is the [qf:p1] bugs. As you have > noticed, there are a lot of them. :-) It is possible that some of these > bugs aren't important to work on, for example because they only affect edge > case conditions that affects a super small subset of users and that wasn't > obvious when the bug was triaged. In some other cases it may turn out that > fixing the bug requires massive amounts of work that is unreasonable to do > in the amount of time we have, or that the right people for it are doing > more important work and can't be interrupted, and so on. Whatever the > issue is, whether the bug was mis-triaged, or can't be fixed, please make > sure to raise it on the bug! In general the earlier these issues are > uncovered the better it is, because everyone can focus their time on more > important work. I wanted to make sure that this wasn't lost in all of the > rush around our communication for Quantum Flow, my apologies if this hasn't > been clear before. > > > On to the acknowledgement section, I hope I'm not forgetting to mention > anyone's name here! > > > - Bas Schouten made it so that we don't clear the compositor > background immediately before drawing into it > <https://bugzilla.mozilla.org/show_bug.cgi?id=1352442>. This made > some painting and scrolling related benchmarks faster > <https://treeherder.mozilla.org/perf.html#/alerts?id=5801>, and fixed > a flickering issue > <https://bugzilla.mozilla.org/show_bug.cgi?id=1330814> in the mean > time! > - Mason Chang made the Youtube settings widget less janky > <https://bugzilla.mozilla.org/show_bug.cgi?id=1351733> on Windows with > D2D when the video is fullscreen. > - David Baron made the flushes caused by the code that watches your > mouse to know which side of the window to put the status bar when you hover > a link less severe > <https://bugzilla.mozilla.org/show_bug.cgi?id=1307134>. > - Neil Deakin removed a synchronous layout flush > <https://bugzilla.mozilla.org/show_bug.cgi?id=1334635> that used to > happen when closing a window which would slow down the window going away. > - Dão Gottwald removed some obsolete tab animation telemetry > <https://bugzilla.mozilla.org/show_bug.cgi?id=1345315> which could > slow down tab animations (yes!). Dão also removed a synchronous > layout flush <https://bugzilla.mozilla.org/show_bug.cgi?id=1356655> > which could slow down detaching a tab into a new window and he also > lazified some code to avoid some more layout flushes > <https://bugzilla.mozilla.org/show_bug.cgi?id=1356663> which were > related to the status panel. > - Markus Stange made the Gecko Profiler not kill your battery after > you stop profiling > <https://bugzilla.mozilla.org/show_bug.cgi?id=830990>, and also made > it so that once you start profiling a thread, you can actually stop > profiling it <https://bugzilla.mozilla.org/show_bug.cgi?id=1346592>. > - Michael Layzell excluded some common file JS file extensions > <https://bugzilla.mozilla.org/show_bug.cgi?id=1352684> from the > expensive computation that we run on Windows to determine the mimetype of a > file from its extension. > - Kris Maglione made it possible to load add-on SDK modules lazily > <https://bugzilla.mozilla.org/show_bug.cgi?id=1314861>. He also made > loading > ExtensionContent.jsm lazy > <https://bugzilla.mozilla.org/show_bug.cgi?id=1317697>. These two > changes together (but probably mostly the former) showed great > improvements on Talos > <https://bugzilla.mozilla.org/show_bug.cgi?id=1314861#c52>. This is > even true for users without any add-ons using the add-on SDK since these > modules are also used in our internal code. > - Robert Helmer created a Go Faster add-on > <https://bugzilla.mozilla.org/show_bug.cgi?id=1356676> to quickly > deploy the fix of bug 1353216 > <https://bugzilla.mozilla.org/show_bug.cgi?id=1353216> to Firefox 52 > users even before they upgrade to Firefox 53 which includes the fix! > - Edouard Oger made Firefox Sync UI code cache the DateTimeFormat > objects <https://bugzilla.mozilla.org/show_bug.cgi?id=1350613> where > possible. > - Alastor Wu made some Fennec media controls code that could be > expensive not run on Firefox desktop > <https://bugzilla.mozilla.org/show_bug.cgi?id=1348803>. > - Makoto Kato added a cache for document encoder objects used by > TextEditor <https://bugzilla.mozilla.org/show_bug.cgi?id=1352882>, in > order to improve the performance of setting the value of > HTMLInputElement.value. > - Tom Schuster optimized Object.hasOwnProperty() > <https://bugzilla.mozilla.org/show_bug.cgi?id=1344469>. This is a > commonly used JavaScript built-in on real web pages, really nice > optimization to have! > - Florian Quèze removed a synchronous layout flush > <https://bugzilla.mozilla.org/show_bug.cgi?id=1353563> that used to > happen when displaying each item in the awesome bar. He improved the > awesomebar even more by caching the one-off search buttons instead of > regenerating them every time we open the popup > <https://bugzilla.mozilla.org/show_bug.cgi?id=1312999>. Furthermore, > he ensured that we don't pay the cost of initializing UITour.jsm for > pages that do not display a UI tour > <https://bugzilla.mozilla.org/show_bug.cgi?id=1349742>. > - Wei-Cheng Pan added telemetry probes for navigation timings and time > to first byte measures > <https://bugzilla.mozilla.org/show_bug.cgi?id=1344893>. > - Shu-yu Guo improved the timing of script source compression by > delaying it until GC > <https://bugzilla.mozilla.org/show_bug.cgi?id=1348134>. Previously we > used to do this when parsing JavaScript (on a separate thread) which is > wasteful because it would mean that we'd have to decompress the compressed > source during page load sometimes, and also burning needless CPU cycles > during JS parsing isn't wise. > - J. Ryan Stinnett made the Developer Toolbar not create a network > listener for every single tab that you have open > <https://bugzilla.mozilla.org/show_bug.cgi?id=1346854>. Besides perf > wins, this means fewer OOM crashes too! > > Thanks for reading! Until next time, happy hacking! > > -- > Ehsan > > _______________________________________________ > firefox-dev mailing list > firefox-...@mozilla.org > https://mail.mozilla.org/listinfo/firefox-dev > > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
