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Bug 121860 - System slows down (freezes) while marking/selecting a lot of single cells by Ctrl+Left Mouse Click
Summary: System slows down (freezes) while marking/selecting a lot of single cells by ...
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Calc (show other bugs)
(earliest affected)
4.4 all versions
Hardware: x86-64 (AMD64) Linux (All)
: medium major
Assignee: Not Assigned
Keywords: bibisectRequest, haveBacktrace, perf, regression
: 114767 130424 131486 (view as bug list)
Depends on:
Blocks: CPU-AT-100%
  Show dependency treegraph
Reported: 2018-12-02 12:02 UTC by einsachtzehn
Modified: 2020-08-23 15:18 UTC (History)
8 users (show)

See Also:
Crash report or crash signature:

Video that shows described behavior and output of top command (1.04 MB, video/mp4)
2018-12-17 19:18 UTC, einsachtzehn
Callgrind output from master (1.21 MB, application/x-xz)
2019-01-25 18:30 UTC, Buovjaga

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Description einsachtzehn 2018-12-02 12:02:30 UTC
After 10-15 cells are selected by STRG+Mouse Click there is a significant loss of speed in marking others. The more you choose the longer one have to wait until cells selection is shown.
Comment 1 einsachtzehn 2018-12-02 13:09:32 UTC
Steps to reproduce:
1 Open a calc sheet
2 press and hold STRG and mark several cells or ranges (between 10-15)

Actual Results:
Calc needs more time to show cells selection the more you try to mark

Expected Results:
Stable performance while marking cells

Reproducible: Always
Comment 2 Durgapriyanka 2018-12-02 16:44:16 UTC
Thank you for reporting the bug. I cannot reproduce the bug in

Build ID: 0c292870b25a325b5ed35f6b45599d2ea4458e77
CPU threads: 2; OS: Windows 6.1; UI render: default; 
Locale: en-US (en_US); Calc: group
Comment 3 einsachtzehn 2018-12-02 20:39:13 UTC
Made some additional tests related to this.
After application restart the behavior occurs between 20-30 cells that are marked
Second try with same sheet still open between 10-20 cells
Seems that the more often you try the earlier the application slows down. 
CPU usage goes up to 100 percent while marking.
Comment 4 einsachtzehn 2018-12-08 22:53:16 UTC
Another notice:
Bug seems to be in connection with marking of several SINGLE cells only.

Bug does not come up if one or more ranges are marked at first that contain a lot of cells before single cells are additionally(!) marked.
Then a huge number of single cells can be marked without any system slow-down.

Bug does come up if a lot of single cells are marked.
Comment 5 einsachtzehn 2018-12-17 19:18:29 UTC
Created attachment 147633 [details]
Video that shows described behavior and output of top command
Comment 6 Roman Kuznetsov 2018-12-21 21:27:46 UTC
confirm in

Build ID: 0412ee99e862f384c1106d0841a950c4cfaa9df1
CPU threads: 4; OS: Linux 4.13; UI render: default; VCL: gtk3; 
Locale: ru-RU (ru_RU.UTF-8); UI-Language: en-US
Calc: threaded
Comment 7 Xisco Faulí 2018-12-26 15:52:28 UTC
Reproduced in

Build ID: c15927f20d4727c3b8de68497b6949e72f9e6e9e

but not in

Version (Build ID: efca6f15609322f62a35619619a6d5fe5c9bd5a)
Comment 8 Buovjaga 2019-01-25 14:26:37 UTC
I can repro with master, but cannot repro with Linux bibisect repos 43, 44, 50max. Weird!!
Comment 9 Buovjaga 2019-01-25 18:30:15 UTC
Created attachment 148664 [details]
Callgrind output from master

Continued clicking until slowness was noticeable.

Arch Linux 64-bit
Build ID: bb30e9e591d5f9f913b3cd8fbaa3c5e412b509bd
CPU threads: 8; OS: Linux 4.20; UI render: default; VCL: gtk3; 
Locale: fi-FI (fi_FI.UTF-8); UI-Language: en-US
Calc: threaded
Built on 23 January 2019
Comment 10 Buovjaga 2019-02-18 12:03:45 UTC
*** Bug 114767 has been marked as a duplicate of this bug. ***
Comment 11 Martin Pietsch 2019-03-05 13:59:26 UTC
I was able to reproduce this behaviour with version on Ubuntu 16.04.6 LTS and ArchLinux. I also found out that this behaviour occurs with KDE in combination with the X11 composer. If you use KDE with the wayland composer, LibreOffice will run as usual.
Comment 12 Buovjaga 2020-06-13 12:06:45 UTC
I only repro this with gtk3 or gen, not with kf5. Maybe it is because of accessibility events.

Arch Linux 64-bit
Build ID: de1b634a151c198584dc152676183f519c50a2da
CPU threads: 8; OS: Linux 5.6; UI render: default; VCL: gtk3
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
Calc: threaded
Built on 12 June 2020
Comment 13 Buovjaga 2020-06-18 18:51:03 UTC
*** Bug 131486 has been marked as a duplicate of this bug. ***
Comment 14 Buovjaga 2020-08-23 15:18:57 UTC
*** Bug 130424 has been marked as a duplicate of this bug. ***