Bug 124346 - High CPU usage when large document open
Summary: High CPU usage when large document open
Status: RESOLVED NOTOURBUG
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
6.2.2.2 release
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-03-27 10:10 UTC by Tim
Modified: 2019-05-01 12:46 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:

Attachments
20 pages of lorem ipsum (46.80 KB, application/vnd.oasis.opendocument.text)
2019-03-28 10:27 UTC, Tim 		Details
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Description Tim 2019-03-27 10:10:10 UTC 
Description:
CPU usage spikes to 110-130% (across 4 cores) when a large document (~260 pages, mainly text) is opened.

Steps to reproduce:
Open large document
Observe CPU spike and fan spin up
Close file
Observe CPU drop and fan spin down

Expected result:
Small spike in CPU usage while opening, overall slight increase in CPU usage, total to remain >10%

Reproducible:
Always

User Profile Reset: 
No, relatively new install upgraded from 6.1.x.

Operating System
Ubuntu 18.10

Install method
Ubuntu LibreOffice PPA
https://launchpad.net/~libreoffice

Additional Info:
Version: 6.2.2.2
Build ID: 1:6.2.2-0ubuntu0.18.10.1~lo1
CPU threads: 4; OS: Linux 4.18; UI render: default; VCL: gtk3; 
Locale: en-AU (en_AU.UTF-8); UI-Language: en-US
Calc: threaded
Comment 1 Tim 2019-03-28 10:27:04 UTC 
Created attachment 150347 [details]
20 pages of lorem ipsum

20 pages of lorem ipsum will cause a spike in CPU usage.
Comment 2 Tim 2019-05-01 12:46:59 UTC 
Further testing has revealed the issue to lie with a LibreOffice grammar extension called LanguageTool. 

This is a known issue in LanguageTool and removing the extension resolved the issue.

See this bug in the LangugeTool bug tracker: https://github.com/languagetool-org/languagetool/issues/1217?_pjax=%23js-repo-pjax-container