Bug 120732 - Lots of time spend in re-rendering of page breaks
Summary: Lots of time spend in re-rendering of page breaks
Status: RESOLVED WORKSFORME
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
4.4.7.2 release
Hardware: All All
: medium trivial
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Writer-Page-Break
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Reported: 2018-10-20 16:48 UTC by Telesto
Modified: 2021-04-01 08:55 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:

Attachments
Example file (85.33 KB, application/vnd.oasis.opendocument.text)
2018-10-20 16:49 UTC, Telesto 		Details
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Description Telesto 2018-10-20 16:48:49 UTC 
Description:
A bit of a artificial example.. But the page breaks are redrawn over and over.
The same happens when scrolling with the floating header button visible

Steps to Reproduce:
1. Open the attached file
2. Open the document in multi-page view -> 4 or more pages in a row
3. Hold enter somewhere on the first page until a empty page is added
4. Undo by holding CTRL+Z and monitor CPU usage


Actual Results:
Slowdown & high CPU usage/ redrawing of page breaks

Expected Results:
Not flickering page break/ more performance


Reproducible: Always


User Profile Reset: No



Additional Info:
Found in
Version: 6.2.0.0.alpha0+
Build ID: b63d48a146c3615f56b6ec83361b3c02ebcbb215
CPU threads: 4; OS: Windows 6.3; UI render: default; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-10-13_23:33:20
Locale: nl-NL (nl_NL); Calc: threaded


Versie: 4.4.7.2 
Build ID: f3153a8b245191196a4b6b9abd1d0da16eead600
Locale: nl_NL
Comment 1 Telesto 2018-10-20 16:49:03 UTC 
Created attachment 145861 [details]
Example file
Comment 2 Chen-Ku 2018-11-29 09:00:29 UTC 
no reproducible
Version: 6.3.0.0.alpha0+ (x64)
Build ID: 0f25a3c36f27fd51453b9a9115f236b83c143684
CPU threads: 12; OS: Windows 10.0; UI render: GL; VCL: win; 
TinderBox: Win-x86_64@42, Branch:master, Time: 2018-11-27_20:06:55
Locale: zh-TW (zh_TW); UI-Language: en-US
Calc: threaded
Comment 3 Telesto 2018-11-29 09:17:14 UTC 
Flicking is only happening with OpenGL disabled. High CPU usage with openGL enabled (but everything is very fast/smooth)

Version: 6.3.0.0.alpha0+
Build ID: f21d2b48bd68424a96aa6cd5572e368208378291
CPU threads: 4; OS: Windows 6.3; UI render: GL; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-11-27_00:26:54
Locale: en-US (nl_NL); UI-Language: en-US
Calc: CL
Comment 4 Dieter 2019-05-01 05:31:04 UTC 
(In reply to Telesto from comment #3)
> Flicking is only happening with OpenGL disabled. High CPU usage with openGL
> enabled (but everything is very fast/smooth)

I can confirm flickering (OpenGL disabled) with

Version: 6.3.0.0.alpha0+ (x64)
Build ID: 421e6fc3cd2e6fe37afbef341e2d0ad7b8edde37
CPU threads: 4; OS: Windows 10.0; UI render: GL; VCL: win; 
TinderBox: Win-x86_64@42, Branch:master, Time: 2019-04-07_01:12:58
Locale: en-US (de_DE); UI-Language: en-US
Calc: threaded

CPU usage increases to almost 10%. Is this what you call high?
Comment 5 Dieter 2021-04-01 08:55:18 UTC 
WORKSFORME with

Version: 7.2.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: f96004096268f5e71120678e32fc8c74055819aa
CPU threads: 4; OS: Windows 10.0 Build 19042; UI render: Skia/Raster; VCL: win
Locale: de-DE (de_DE); UI: en-GB
Calc: CL