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 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to libreoffice in Ubuntu. https://bugs.launchpad.net/bugs/1825513 Title: High CPU usage when large document open Status in LibreOffice: Won't Fix Status in libreoffice package in Ubuntu: Won't Fix Bug description: 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. Bug also filed against Libreoffice 6.2.2 installed on Ubuntu 18.10 via PPA. See: https://bugs.documentfoundation.org/show_bug.cgi?id=124346 ProblemType: Bug DistroRelease: Ubuntu 19.04 Package: libreoffice-writer 1:6.2.2-0ubuntu2 ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6 Uname: Linux 5.0.0-13-generic x86_64 ApportVersion: 2.20.10-0ubuntu27 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Fri Apr 19 22:04:37 2019 InstallationDate: Installed on 2019-02-04 (74 days ago) InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3) SourcePackage: libreoffice UpgradeStatus: Upgraded to disco on 2019-04-19 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/df-libreoffice/+bug/1825513/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
