Thanks for helping test! Feel free to disable the feature for now since right now enabling this has been de-prioritize for the time being while we focus on shipping APZ and E10S.
On Tue, Mar 29, 2016 at 4:55 PM, Jonas Sicking <jo...@sicking.cc> wrote: > Hi Benoit, > > There's two problems that I've seen related to scrolling, and so > possibly the result of APZ. > > The most obvious one is that if the child process is busy doing > things, then the scrollable area seems "sticky". When you start > scrolling there's a noticeable delay before the page starts scrolling. > > My guess is that we send some message to the child process when > scrolling is initiated and don't start scrolling until the child > process responds (possibly with some form of timeout)? > > This isn't noticeable on the example page that you provided, possibly > because the child process is quite responsive before we start the > heavy painting operations. > Yes, this is how it's implemented and a design limitation. Given that the design changed a lot since it was planned it might be possible to remove this limitation down the road and have APZ initiate the scroll. > The other problem, which is more serious, is that every now and then > the browser seems to get into a state where I can't use the trackpad > at all to do scrolling. The scroll bar is displayed, as is common when > using the trackpad to scroll, but no scrolling actually happens. > > The only way I can scroll when the browser is in this state is to > hover the scrollbar and click below the scroll thumb, which enables > scrolling one page at a time. > > The only way to get out of the state is by restarting the browser. > > Sadly this happens very infrequently, so I haven't been able to create > steps to reproduce, nor seen any pattern in where it triggers. > As Felipe points out this is a recent APZ regression and isn't tied to this feature. > > / Jonas > > > On Wed, Feb 17, 2016 at 10:35 AM, Benoit Girard <bgir...@mozilla.com> > wrote: > > Currently APZ does not cause scrollbar initiated scrolling to be async. > > I've been working in fixing this and I'd like some help testing it out > > before enabling it on Nightly. If you're interested please flip > > 'apz.drag.enabled' to true and restart. If you find any issue please make > > it block https://bugzilla.mozilla.org/show_bug.cgi?id=1211610. > > > > I've got a test page here to confirm that it's turned on properly: > > http://people.mozilla.org/~bgirard/scroll_no_paint.html > > > > Scrolling on this page is slow in FF because it hits a performance bugs > in > > layer construction code. However with APZ the scrolling is smooth and a > bit > > checkerboard-y instead. If you have 'layers.acceleration.draw-fps' set > you > > should notice the left most FPS counter at 60 FPS while the middle > counter > > will be much lower. This is APZ handling the scroll. > > > > Happy Testing, > > Benoit > > _______________________________________________ > > dev-platform mailing list > > dev-platform@lists.mozilla.org > > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
