Multi-monitor: clone mode much slower (stutters) than sidebyside
Bug #1213801 reported by
Daniel van Vugt
This bug affects 1 person
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Mir |
Fix Released
|
Medium
|
Daniel van Vugt | ||
| mir (Ubuntu) |
Fix Released
|
Medium
|
Unassigned | ||
Bug Description
I just noticed a strange performance penalty of clone mode. If running several clients, in clone mode some of them (notably demo_client_
This is probably a symptom of clone mode forcing each page flip to wait for multiple vblanks...
And yes, I have tested with and without the "switch" branch. The bug existed before that landed.
Related branches
lp://qastaging/~vanvugt/mir/async-page-flips
- Alexandros Frantzis (community): Approve
- Alan Griffiths: Approve
- PS Jenkins bot (community): Approve (continuous-integration)
-
Diff: 496 lines (+218/-60)8 files modifiedsrc/platform/graphics/mesa/display.cpp (+11/-0)
src/platform/graphics/mesa/display_buffer.cpp (+72/-31)
src/platform/graphics/mesa/display_buffer.h (+4/-1)
tests/unit-tests/graphics/mesa/mock_kms_output.h (+52/-0)
tests/unit-tests/graphics/mesa/test_cursor.cpp (+2/-19)
tests/unit-tests/graphics/mesa/test_display.cpp (+5/-7)
tests/unit-tests/graphics/mesa/test_display_buffer.cpp (+62/-0)
tests/unit-tests/graphics/mesa/test_display_multi_monitor.cpp (+10/-2)
Revision history for this message
| Daniel van Vugt (vanvugt) wrote | #1 |
| Changed in mir: | |
| importance: | Undecided → High |
| status: | New → Triaged |
| Changed in mir: | |
| assignee: | nobody → Daniel van Vugt (vanvugt) |
| status: | Triaged → In Progress |
Revision history for this message
| Daniel van Vugt (vanvugt) wrote | #2 |
| Changed in mir: | |
| milestone: | none → 0.1.5 |
| Changed in mir: | |
| milestone: | 0.1.5 → 0.1.6 |
Revision history for this message
| PS Jenkins bot (ps-jenkins) wrote | #3 |
| Changed in mir: | |
| status: | In Progress → Fix Committed |
| Changed in mir: | |
| importance: | High → Medium |
| Changed in mir: | |
| status: | Fix Committed → Fix Released |
Revision history for this message
| Daniel van Vugt (vanvugt) wrote | #4 |
| Changed in mir (Ubuntu): | |
| importance: | Undecided → Medium |
| status: | New → Fix Released |
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On the other hand, waiting for all outputs' page flips to complete does avoid tearing. And this bug doesn't occur until the rendering load is high.
I think we need to choose between:
(a) Sometimes low frame rate (stutter) but never tearing; or
(b) Always smooth frame rate but tearing on /some/ monitors in clone mode.
I'm really hoping there's an option (c).