I wonder if this bug might have been solved accidentally in the same way
as bug 1388490...
** Changed in: mir
Assignee: Thomas Voß (thomas-voss) => Daniel van Vugt (vanvugt)
** Changed in: mir
Status: New => Incomplete
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to mir in Ubuntu.
https://bugs.launchpad.net/bugs/1488386
Title:
[performance] Rendering is only smooth while you're touching the
screen
Status in Mir:
Incomplete
Status in QtMir:
New
Status in Unity System Compositor:
In Progress
Status in mir package in Ubuntu:
New
Status in qtmir package in Ubuntu:
New
Bug description:
On some devices (mako at least) it's possible to force double
buffering and it will often keep up:
restart unity8 QML_NO_TOUCH_COMPRESSION=1 MIR_SERVER_NBUFFERS=2
Curiously however it only keeps up smoothly (eg. during a dash scroll)
while you're touching the screen. If you lift off or fling the dash
then it immediately stutters, quite badly.
So the issue is not that the device can't keep up with double buffering. It
seems more like we're not keeping the kernel sufficiently awake and it's
clocking down prematurely, as soon as we're not touching it. Certainly
adjusting the variables in:
/sys/devices/system/cpu/cpu0/cpufreq
it is possible to raise the performance and minimum frequency to make double
buffering smooth.
The challenge of this bug is to find a way in Mir/QtMir to keep the
kernel more awake so it doesn't clock down when we need smooth
animations and we're not touching the screen.
Also note that while this bug sounds like bad news for mako, mako is
actually the best performing device. Others like arale don't reliably
speed up in response to short touches.
To manage notifications about this bug go to:
https://bugs.launchpad.net/mir/+bug/1488386/+subscriptions
--
Mailing list: https://launchpad.net/~touch-packages
Post to : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help : https://help.launchpad.net/ListHelp
