Compiz

[performance] glXSwapIntervalEXT called every frame, which is very slow on Nvidia.

Bug #1051286 reported by Sam Spilsbury on 2012-09-15

This bug affects 4 people

Affects		Status	Importance	Assigned to	Milestone
	Compiz	Fix Released	Medium	Daniel van Vugt	Compiz 0.9.8.4

Bug Description

glXSwapIntervalEXT is called every frame, when it only needs to be called once when using buffer swaps (eg turned on).

See original description

Tags:

Related branches

lp://qastaging/~compiz-team/compiz/compiz.fix_1051286

Superseded for merging into lp://qastaging/compiz/0.9.9

Daniel van Vugt: Needs Fixing on 2012-10-02

jenkins (community): Needs Fixing (continuous-integration) on 2012-10-02

Sam Spilsbury: Pending requested 2012-09-28

Superseded for merging into lp://qastaging/compiz/0.9.8

Sam Spilsbury: Needs Resubmitting on 2012-09-28

Daniel van Vugt: Needs Resubmitting on 2012-09-24

jenkins (community): Needs Fixing (continuous-integration) on 2012-09-22

lp://qastaging/~vanvugt/compiz/fastSwapInterval

Merged into lp://qastaging/compiz/0.9.8 at revision 3386

Sam Spilsbury: Approve on 2012-09-25

jenkins (community): Approve (continuous-integration) on 2012-09-25

lp://qastaging/~sil2100/compiz/ubuntu_0.9.8.4 (Merged)

Sam Spilsbury (smspillaz) on 2012-09-15

tags:

added: gdebugger performance

Sam Spilsbury (smspillaz) on 2012-09-15

Changed in compiz:
milestone:	none → 0.9.8.4

Sam Spilsbury (smspillaz) on 2012-09-19

Changed in compiz:
status:	New → In Progress

Sam Spilsbury (smspillaz) on 2012-09-19

Changed in compiz:
assignee:	nobody → Sam Spilsbury (smspillaz)
importance:	Undecided → High

Revision history for this message

Sam Spilsbury (smspillaz) wrote on 2012-09-19:

I can't reproduce this anymore. I found that the major thing which boosted performance was not letting the driver pick the refresh rate.

Nevertheless, not calling into OpenGL lots is probably a good thing.

description:	updated
Changed in compiz:
importance:	High → Medium

Daniel van Vugt (vanvugt) on 2012-09-24

summary:	- [performance][nvidia] glXSwapIntervalEXT called every frame, when it - only need to be called once + [performance] glXSwapIntervalEXT called every frame, which is very slow + on Nvidia.
tags:	added: nvidia-is-slow

Revision history for this message

Alex Baines (abaines) wrote on 2012-09-24:

I'm experiencing this bug in any OpenGL application which sets its own swap interval to 1, either because it called glXSwapInterval{EXT, SGI} or because sync to vblank is forced on in nvidia-settings (or because the __GL_SYNC_TO_VBLANK environment variable is set to 1).

It causes the cpu usage of Xorg and compiz to be abnormally high, and the OpenGL application running will be very stuttery.

It is only present when compiz's "sync to vblank" option is also checked, and can be worked-around by commenting out the glXSwapInterval(0) line in the waitForVideoSync function of plugins/opengl/src/screen.cpp

Revision history for this message

Daniel van Vugt (vanvugt) wrote on 2012-09-25:

I tested this and cannot reproduce any performance regression under nvidia with glXSwapInterval(0). I can only confirm a slowdown with glXSwapInterval(1). However enough people seem to agree that even glXSwapInterval(0) is slow for them.

Changed in compiz:
status:	In Progress → Incomplete
status:	Incomplete → In Progress

Unity Merger (unity-merger) on 2012-09-25

Changed in compiz:
status:	In Progress → Fix Committed

Revision history for this message

Daniel van Vugt (vanvugt) wrote on 2012-09-25:

Fix committed into lp:compiz at revision 3386

Changed in compiz:
assignee:	Sam Spilsbury (smspillaz) → Daniel van Vugt (vanvugt)

Daniel van Vugt (vanvugt) on 2012-09-28

Changed in compiz:
status:	Fix Committed → Fix Released

Report a bug

This report contains Public information

Everyone can see this information.

Duplicates of this bug

Bug #1055154

You are

Subscribing...

Edit bug mail

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.