Description:
FILESAVE. Back in the good old days of Ubuntu 22.04 running LibreOffice Calc 1:7.3.7-0ubuntu0.22.04.7 on amd64, I could use "Save AutoRecovery information" to autosave a 5MB 277 sheet spreadsheet every 15 minutes without disruption. Since upgrading to Ubuntu 24.04 LO Calc 4:24.2.7 on amd64 and Ubuntu 24.10 LO Calc 4:24.8.4.2 on aarch64, I experience massive 5 GB memory utilisation blowouts in the soffice.bin process during autosave causing painful delays of up to a minute. This blowout occurs even if the only change is to bold text in one cell. The delay reduces as I delete worksheets from my spreadsheet. e.g. a  10 worksheet sample sees a 200MB memory blowout.

Steps to Reproduce:
1. Run gnome-monitor to monitor memory utilisation and ps -ely | | awk '/soffice.bin$/{print "RSS: "$8" / SZ: "$9}' e.g. before calc 3.5GB, 453K/397K
2. Open sample 0.5MB spreadsheet; Tools -> Options: Load/Save: General: Save: tick and set "Save AutoRecovery information every" 1 "minute." Start 1 minute timer e.g. on your phone, then bold text a cell. Memory usage stays much same as above
3. After the minute is up, wait for autosave (orange bar runs along bottom of Calc window) and then re-check memory: Now 3.7GB 650K/495K

Actual Results:
In this case of a 10 worksheet 0.5MB sample, you see a 200MB memory blow-out.
By the time you get to 277 worksheet 4.8MB spreadsheet, the memory blows out from 4.4 to 9.1 GB, and soffice.bin process memory blows out:
After change but before autosave:
RSS:  747012 SZ:  470429
After autsave:
RSS: 5356176 SZ: 1752282

Memory is not released until you full exit all LibreOffice windows.
In my case I had 16GB physical memory to hold the blowout but even so it took over a minute to autosave, severely impacting the usability of LO Calc. It's foreseeable that with a more typical 8 GB laptop, you're going to be swapping to disk and really hang the user for minutes.

Expected Results:
I expected the performance I saw in LibreOffice Calc 7.3.7 on Ubuntu 22.04.07 which was instantaneous autosaves with no perceptible delays.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
The problem occurs with both .ods and .xls versions of the file and on both Calc 24.2.7 on Ubuntu 24.04 amd64 and Calc 24.8.4.2 on Ubuntu 24.10 aarch64. And with autosave set to 1 minute and 10 minutes.

Version: 24.8.4.2 (AARCH64) / LibreOffice Community
Build ID: 480(Build:2)
CPU threads: 8; OS: Linux (misparsed version); UI render: default; VCL: gtk3
Locale: en-AU (en_AU.UTF-8); UI: en-US
Ubuntu package version: 4:24.8.4-0ubuntu0.24.10.2
Calc: threaded