Bug 170576 - Writer extremely slow/unresponsive after opening long document; page count initially wrong and updates only after ~15 seconds (regression)
Summary: Writer extremely slow/unresponsive after opening long document; page count in...
Status: UNCONFIRMED
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
24.8.4.2 release
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-02-02 19:33 UTC by vasili
Modified: 2026-02-02 19:33 UTC (History)
0 users

See Also:
Crash report or crash signature:


Attachments

Note You need to log in before you can comment on or make changes to this bug.
Description vasili 2026-02-02 19:33:51 UTC
Description:
Description
LibreOffice Writer becomes very slow and mostly unresponsive for ~10–15 seconds after opening a long text document (~77 pages). During this time, editing is effectively blocked.
The document opens visually quickly, but layout appears incomplete: the page counter initially shows ~17 pages and only later jumps to the correct value (77 pages). Responsiveness returns only after the page count stabilizes.
This behavior started recently and did not occur in earlier LibreOffice versions on the same system with the same document.



Steps to Reproduce:
1. Open LibreOffice Writer
2. Open a long text document (~70–80 pages, mostly plain text, no tables, no footnotes, no tracked changes)
3. Observe page count and try to edit immediately
2.
3.

Actual Results:
    • Document window opens quickly
    • Page counter initially shows an incorrect low value (~17 pages)
    • Writer is sluggish or unresponsive for ~10–15 seconds
    • After that delay, page count updates to correct value (77 pages)
    • Editing becomes responsive only after that

Expected Results:
   • Page count should be correct shortly after opening
    • Editing should be responsive immediately after document opens
    • No long blocking layout phase before editing is possible


Reproducible: Always


User Profile Reset: No

Additional Info:
Regression
Yes.
The same document behaved normally in earlier LibreOffice versions (before 25.8.x). The slowdown appeared approximately one month ago after an update.

Additional Information
    • Fedora XFCE Spin (X11, not Wayland)
    • Intel CPU with integrated GPU
    • LibreOffice UI backend: VCL: gtk3
    • Skia not in use (SAL_DISABLE_SKIA has no effect)
    • Smooth scrolling disabled
    • Anti-aliasing disabled
    • Document size: ~220 kB
    • Document structure: mostly plain text, no complex elements
This could be a Writer layout regression causing delayed full pagination and blocking editing until layout completes.

Version Information
LibreOffice 25.8.4.2.2 (RPM)
Build date: 2024-12-21
Operating System: Fedora Linux (XFCE, X11)

Follow-up comment
Downgrading LibreOffice from 25.8.4.2 to 25.8.1.1 restores good editing responsiveness after the document has fully loaded.
However, the initial document layout still takes ~15 seconds, during which the page count is initially incorrect (17 pages) and only later updates to the correct value (77 pages).
The regression therefore appears to affect incremental editing performance rather than the initial full layout.