The issue is device-specific and requires integration with SOC-specific
infrastructure. We started wiring up the required functionality across
the stack, with the tablet being the first real consumer. The changes
you are interested in are:

  * 
http://bazaar.launchpad.net/~unity-system-compositor-team/unity-system-compositor/trunk/revision/280
  * http://bazaar.launchpad.net/~phablet-team/platform-api/trunk/revision/317

We require changes to the Android portions of the platform API, though,
with the tablet being the first device that has the required platform
api functions implemented on the Android side. The landing for USC can
be found here:

  * https://requests.ci-train.ubuntu.com/#/ticket/1097

With the silo installed, device performance is boosted for interactive
scenarios, specifically after deep sleep.

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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] Double buffering is only smooth while you're touching it

Status in Mir:
  New
Status in QtMir:
  New
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.

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