Bug 100009 - Using highlight tool makes LibreOffice use 100% of one core
Summary: Using highlight tool makes LibreOffice use 100% of one core
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
(earliest affected) release
Hardware: x86-64 (AMD64) All
: medium normal
Assignee: Not Assigned
Keywords: bibisected, perf, regression
Depends on:
Reported: 2016-05-23 13:33 UTC by Zar
Modified: 2017-07-21 14:41 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:

bibisect details (2.44 KB, text/plain)
2017-06-15 02:38 UTC, Terrence Enger
reverse bibisect in daily dbgutil repo (2.09 KB, text/plain)
2017-07-21 14:41 UTC, Terrence Enger

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Description Zar 2016-05-23 13:33:21 UTC
Conditions: as soon as I turn on the highlight tool in Writer and start highlighting, CPU usage of soffice.bin jumps to 100% of one core and stays there. 

As soon as I turn the tool off, it drops back to normal. 

the CPU usage goes up to 100% once I start highlighting; if I select the highlight tool but do nothing with it, CPU usage remains normal. 

It is reproducible every single time without exception. 

Ubuntu 14.04 LTS, LibreOffice 5.1.3rc2 as per about dialog; from the LibreOffice fresh PPA at Launchpad.net

Comment 1 Terrence Enger 2016-05-24 04:44:58 UTC
I see the reported high CPU usage in both daily Linux dbgutil bibisect
version 2016-05-16 and a local build of commit 1da942c, pulled
2016-05-11 01:28 UTC.

(1) In a terminal window, run top.
(2) Start Writer from the command line.
(3) Resize and move windows so that the Writer window and output from
    top are both visible.
(4) In Writer window, click on highlight icon.
(5) In Writer window, type "T".  Observe that top reports high CPU
    usage by soffice.bin.
(6) In Writer window, type "<Esc>".  Observe that CPU usage drops back
    to normal.

I am setting bug status NEW.
Comment 2 panos 2016-05-24 06:47:37 UTC
I confirm this bug in LibreOffice, Fedora 23. CPU goes up as soon as you start highlighting and stops when you deactivate the highlight tool.
Comment 3 Telesto 2017-06-14 18:41:30 UTC
Repro with
Build ID: 076ed447f694239d5c67adee528ea6e471d909ff
CPU threads: 4; OS: Windows 6.19; UI render: default; 
TinderBox: Win-x86@42, Branch:master, Time: 2017-06-09_23:54:20
Locale: nl-NL (nl_NL); Calc: CL

and with
Build ID: 5e3e00a007d9b3b6efb6797a8b8e57b51ab1f737
CPU Threads: 4; OS Version: Windows 6.2; UI Render: default; 
Locale: en-US (nl_NL)

but not with
Build ID: 490fc03b25318460cfc54456516ea2519c11d1aa-GL
Locale: en-US (nl_NL)
Comment 4 Zar 2017-06-14 18:59:19 UTC
Just writing to confirm this bug still exists in LibreOffice version, installed on KDE Neon User Edition 5.10 (=Ubuntu 16.04 LTS). 

Exactly the same procedure to reproduce the bug and it is still reproducible every time.
Comment 5 Terrence Enger 2017-06-15 02:38:44 UTC
Created attachment 134040 [details]
bibisect details

Working in debian-stretch in lo-linux-dbgutil-daily-till51 bibisect
repository, I see that the high CPU usage came into LO somewhere in
the 24 commits to master ...

          commit    date        s-h
          --------  ----------  --------
    good  2b9d93ba  2015-06-13  a9286c30
    bad   772f8de0  2015-06-14  ad84b40b

I am removing keyword bibisectRequest and adding bibisected.
Comment 6 Telesto 2017-07-21 09:49:43 UTC
No repro with:
Build ID: a9588baca8137f51e2ca72e40b1f448b0e1885d1
CPU threads: 4; OS: Windows 6.19; UI render: default; 
TinderBox: Win-x86@42, Branch:master, Time: 2017-07-21_02:58:26
Locale: nl-NL (nl_NL); Calc: CL
Comment 7 Terrence Enger 2017-07-21 14:41:05 UTC
Created attachment 134767 [details]
reverse bibisect in daily dbgutil repo

Working in debian-stretch in the daily Linux dbgutil bibisect
repository, I see that the CPU usage dropped somewhere in the range

              commit    date        s-h
              --------  ----------  --------
    high CPU  bf880ccd  2017-07-13  e333183d
    low CPU   8f17f4f7  2017-07-14  b9bda1d7

I am setting status RESOLVED WORKSFORME.