Bugzilla

(In reply to Robert Mader [:rmader] from comment #3)
> Personally I'd say keyboard scrolling is more choppy (also see bug 1601962 comment 13). I'll attach some profiles, scrolling on bug 1601962, maybe that helps?
> 1. touchpad: https://share.firefox.dev/2WYVhm0
> 2. keyboard: https://share.firefox.dev/3pB6khz
> 3. keyboard with `apz.force_disable_desktop_zooming_scrollbars:true`: https://share.firefox.dev/2LbzsNp
> 
> Given that in the 3. case rendering doesn't keep up with scrolling, there's of course the possibility that WR is just too slow here? Would surprise me though.

Thanks for that.

Interesting. Comparing the last two there is a lot more displaylist building happening in the content process in 2 then in 3. So maybe apz controlling and updating the main thread scroll position means we can't avoid a display list build whereas if he main thread controls the scroll position is can avoid the display list build?

What do profiles 2 and 3 looks like if you use page up/down or space bar to scroll instead of many arrow key presses?

(In reply to Robert Mader [:rmader] from comment #3)
> Personally I'd say keyboard scrolling is more choppy (also see bug 1601962 comment 13). I'll attach some profiles, scrolling on bug 1601962, maybe that helps?
> 1. touchpad: https://share.firefox.dev/2WYVhm0
> 2. keyboard: https://share.firefox.dev/3pB6khz
> 3. keyboard with `apz.force_disable_desktop_zooming_scrollbars:true`: https://share.firefox.dev/2LbzsNp
> 
> Given that in the 3. case rendering doesn't keep up with scrolling, there's of course the possibility that WR is just too slow here? Would surprise me though.

Thanks for that.

Interesting. Comparing the last two there is a lot more displaylist building happening in the content process in 2 then in 3. So maybe apz controlling and updating the main thread scroll position means we can't avoid a display list build whereas if the main thread controls the scroll position it can avoid the display list build?

What do profiles 2 and 3 looks like if you use page up/down or space bar to scroll instead of many arrow key presses?