desktop-packages team mailing list archive

[Kevin DuBois <kevin.dubois@xxxxxxxxxxxxx>]

I see the same symptoms on my intel system. The easiest way to reproduce
the systems for me is to have a host (in bypass mode, with nbuffers=2),
a nested server (with nbuffers = 2 or nbuffers = 3), and then run
eglplasma connected to the nested server.

If egltriangle is running, the host server composites at 60fps. If
eglplasma is running, the host server composites at 30fps.

-- 
You received this bug notification because you are a member of Desktop
Packages, which is subscribed to mesa in Ubuntu.
https://bugs.launchpad.net/bugs/1377872

Title:
  Double-buffered compositing performance is sometimes very poor (30
  FPS) on intel

Status in Mesa:
  Confirmed
Status in Mir:
  Confirmed
Status in mesa package in Ubuntu:
  Confirmed

Bug description:
  Double-buffered compositing performance is sometimes artificially poor
  on some intel systems. When this happens the frame rate seen is halved
  - about 30 FPS. However at the same time, Mir is observed to use very
  little render time and both the CPU and GPU are still mostly idle.
  It's just the Intel DRM logic sometimes takes two frames (~32ms) to
  complete a single page flip.

  Two known workarounds avoid the issue:
    (a) Add glFinish() into the mesa DisplayBuffer code; or
    (b) env INTEL_DEBUG=sync for the Mir server binary.

To manage notifications about this bug go to:
https://bugs.launchpad.net/mesa/+bug/1377872/+subscriptions