Bug 122968 - Stuttering/ judder while scrolling using page down (pages per second rate has worsened)
Summary: Stuttering/ judder while scrolling using page down (pages per second rate has...
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
5.4.1.2 release
Hardware: All Windows (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: bibisectRequest, perf, regression
Depends on:
Blocks: Scrolling-PageUpDown
  Show dependency tree / graph
 
Reported: 2019-01-25 14:06 UTC by Telesto
Modified: 2020-01-13 03:36 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:

Attachments
Example file (18.29 MB, application/vnd.oasis.opendocument.text)
2019-01-25 14:07 UTC, Telesto 		Details
Flamegraph (329.93 KB, application/x-bzip)
2020-01-12 17:44 UTC, Julien Nabet 		Details
View All Add an attachment (proposed patch, testcase, etc.)

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Description Telesto 2019-01-25 14:06:22 UTC 
Description:
Stuttering/ judder while scrolling using page down. A recycled bug-doc.. can't find the source bug

Steps to Reproduce:
1. Open attached file
2. Press Page down & monitor CPU

Actual Results:
Stuttering/ slow down

Expected Results:
Smooth scroll


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 6.3.0.0.alpha0+
Build ID: 6740443311268b7d918bf4f43134d64fb78a0109
CPU threads: 4; OS: Windows 6.3; UI render: GL; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2019-01-15_23:37:04
Locale: nl-NL (nl_NL); UI-Language: en-US
Calc: CL

And with
Version: 5.4.1.0.0+
Build ID: f200d5700782ae179fd96b6ad4b0fe8e7edd1616
CPU threads: 4; OS: Windows 6.29; UI render: default; 
Locale: nl-NL (nl_NL); Calc: CL
Comment 1 Telesto 2019-01-25 14:07:02 UTC 
Created attachment 148657 [details]
Example file
Comment 2 Durgapriyanka 2019-01-25 18:20:32 UTC 
When I try to open the file, LO becomes unresponsive.

Version: 6.3.0.0.alpha0+
Build ID: 3c964980da07892a02d5ac721d80558c459532d0
CPU threads: 2; OS: Windows 6.1; UI render: default; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-12-12_02:07:45
Locale: en-US (en_US); UI-Language: en-US
Calc: threaded
Comment 3 Buovjaga 2019-02-03 12:23:15 UTC 
I found the most informative metric is to hold page down for 10 seconds, stop, observe the page you reached. With 4.3.0 I reached page 100. With 5.0.2 I reached 50. With 6.0 bibisect repo I reached 19 (same ballpark for newer ones). Unfortunately, I did not get the worst value in the bibisect repo for 5.4, so I am unable to perform a bibisect.

Maybe I could try to find the worsening after 4.3 on Linux.
Comment 4 Buovjaga 2019-02-03 14:06:52 UTC 
(In reply to Buovjaga from comment #3)
> Maybe I could try to find the worsening after 4.3 on Linux.

No luck. I was not able to observe a difference. Linux behaves differently from Windows in that it keeps scrolling a long time after you finish pressing PgDn.
Comment 5 Telesto 2020-01-12 17:21:27 UTC 
Repro with
Version: 6.5.0.0.alpha0+ (x64)
Build ID: ce685f64f38551e7984155783c9c7660d986abf6
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: GL; VCL: win; 
Locale: nl-NL (nl_NL); UI-Language: en-US
Calc: CL

A flamegraph would be nice
Comment 6 Julien Nabet 2020-01-12 17:44:11 UTC 
Created attachment 157088 [details]
Flamegraph

Here's a Flamegraph retrieved on pc Debian x86-64 with master sources updated today.
(I waited some seconds before killing perf trace).