Bug 120916 - Slow and choppy page down in multi-page (5 or 6 pages in a row)
Summary: Slow and choppy page down in multi-page (5 or 6 pages in a row)
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
6.2.0.0.alpha1+
Hardware: All Windows (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: HarfBuzz-regressions
  Show dependency treegraph
 
Reported: 2018-10-25 17:49 UTC by Telesto
Modified: 2019-02-18 08:47 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
Example file (38.43 KB, application/vnd.oasis.opendocument.text)
2018-10-25 17:49 UTC, Telesto
Details

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Description Telesto 2018-10-25 17:49:15 UTC
Description:
Slow and choppy page down in multi-page (5 or 6 pages in a row)

Steps to Reproduce:
1. Open the attached file
2. Zoom out; 5 or 6 pages for every row
3. Page down (count time before reaching the bottom)
4. Compare this with attachment 145907 [details] (smooth page down) or LibreOffice 5.2

Actual Results:
16 seconds or so

Expected Results:
10 seconds


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 6.2.0.0.alpha1+
Build ID: 0378bfcea51ff0f379d0954aa6740f1829909dc3
CPU threads: 4; OS: Windows 6.3; UI render: default; VCL: win; 
TinderBox: Win-x86@42, Branch:master, Time: 2018-10-24_00:14:48
Locale: nl-NL (nl_NL); Calc: CL
Comment 1 Telesto 2018-10-25 17:49:52 UTC
Created attachment 146007 [details]
Example file
Comment 2 Durgapriyanka 2018-11-20 18:19:27 UTC
Thank you for reporting the bug. I can confirm that the bug is present.

Version: 6.0.6.2
Build ID: 0c292870b25a325b5ed35f6b45599d2ea4458e77
CPU threads: 2; OS: Windows 6.1; UI render: default; 
Locale: en-US (en_US); Calc: group
Comment 3 Buovjaga 2019-01-21 12:44:20 UTC
NEW per comment 2.
Telesto: can you regression test this?
Comment 4 Telesto 2019-01-23 10:27:03 UTC
(In reply to Buovjaga from comment #3)
> NEW per comment 2.
> Telesto: can you regression test this?

More of the same Harbuzz fall-out. So in fact bug 113350 or the list of 'duplicates' (which is depending on the view about duplicates). Underlying issue is the same area's differ

The solution of Miklos is working (reducing calls & buffer) (for example https://gerrit.libreoffice.org/#/c/59159/). However half-way solution, because scope is limited to main editor (or at least that's my impression).. 

In general happy with he approach; phased repairs instead of all at once. However with the risk the follow up is dropped because of decreased importance (or interest).  Still hoping for a follow-up :-). Performance of PDF export, Print preview, Print quite horrible for large documents.

Repro with:
Versie: 5.3.7.2 
Build ID: 6b8ed514a9f8b44d37a1b96673cbbdd077e24059
CPU Threads: 4; Versie besturingssysteem:Windows 6.2; UI Render: standaard; Layout-Engine: nieuw; 
Locale: nl-NL (nl_NL); Calc: CL

No repro with
Versie: 5.3.7.2 
Build ID: 6b8ed514a9f8b44d37a1b96673cbbdd077e24059
CPU Threads: 4; Versie besturingssysteem:Windows 6.2; UI Render: standaard; Layout-Engine: oud; 
Locale: nl-NL (nl_NL); Calc: CL

Tools -> Options -> Advanced: Expert Configuration search for "TextLayoutEngine" and edit to change "new|old" as needed. (Source: bug 89870 comment 32)
Comment 5 Buovjaga 2019-01-23 14:49:48 UTC
Miklos said to keep this open.

Telesto: are you testing with Automatic spellchecking on or off? I get 5 secs on Linux with off and 19 secs with on. Thinking how to profile this.