Ubuntu
xorg-server package

X apps are laggy under Xmir

Bug #1502738 reported by Daniel van Vugt
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
xorg-server (Ubuntu)
Expired
Medium
Unassigned

Bug Description

X apps are very laggy under Xmir.

This is a simple problem whereby Xmir has introduced a second layer of nesting on top of an already laggy nested system.

I have a solution for this bug ready, but it can't be enabled until Unity8 bug 1497828 is fixed.

Daniel van Vugt (vanvugt)
Changed in xorg-server (Ubuntu):
importance: Undecided → Medium
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Still blocked by QtMir bug 1497828? Need to retest...

Revision history for this message
Daniel van Vugt (vanvugt) wrote :

https://git.launchpad.net/~xmir-team/xorg-server/+git/xmir/commit/?id=3f1e0ab7e5a8af5578cd10492c1f93e9bf97e252

Changed in xorg-server (Ubuntu):
status: In Progress → Fix Committed
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package xorg-server - 2:1.17.3-2ubuntu3

---------------
xorg-server (2:1.17.3-2ubuntu3) xenial; urgency=medium

  * debian/patches/xmir.patch:
    - Add ability to set title for XMir (LP: #1542028)
    - Use swapinterval 0 (LP: #1502738)
    - Add sufficient traversal hacks for Matchbox

 -- Robert Ancell <email address hidden> Mon, 15 Feb 2016 17:32:21 -0800

Changed in xorg-server (Ubuntu):
status: Fix Committed → Fix Released
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Un-fixed on trunk. I'm finding particularly under Unity8 the reduction is smoothness is annoying. Even though there is a reduction in lag.

Possibly the frame scheduling logic needs to be reassessed with interval zero in mind. Also a working GLX swap interval implementation would help GLX apps.

Changed in xorg-server (Ubuntu):
status: Fix Released → Triaged
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

In case anyone is wondering, the two bugs that were blocking this feature remain fixed. It's not like I didn't verify them thoroughly. Just that it now looks like there are approximately two more new previously unforeseen bugs that are getting in the way.

Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Now bug 1546401 is blocking this. And I think possibly another one...

Daniel van Vugt (vanvugt)
summary: - X apps are very laggy under Xmir
+ X apps are laggy under Xmir
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Bug 1546401 is indeed not a bug, but is also still true. Setting swap interval 0 on the server without any replacement throttling will hurt client performance.

Revision history for this message
Daniel van Vugt (vanvugt) wrote :

I think this should mostly be fixed now in Mir 0.26 due to client-side vsync. However as previously mentioned, more work is required specifically to make the Xmir case optimal:
   https://code.launchpad.net/~vanvugt/mir/client-side-vsync/+merge/314313

Changed in xorg-server (Ubuntu):
status: Triaged → Incomplete
assignee: Daniel van Vugt (vanvugt) → nobody
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for xorg-server (Ubuntu) because there has been no activity for 60 days.]

Changed in xorg-server (Ubuntu):
status: Incomplete → Expired
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