Memory Leak? (v2.31)

[hayaku]

Hello.

I must admit, I wouldn't have expected that my RTX4090 would ram out running, Sigil, but it seems to be the case with v2.31



Is this memory leak documented, with a fix on the way?

Sometimes, I've come back home to find Sigil consuming >20GB of VRAM. Quite concerning!

Thanks for this app, keep up the good work everybody!

[DiapDealer]

It's always possible. A successful Windows QtWebEngine compilation nearly always has warnings of potential memory leaks. But the Qt used with Sigil 2.3.1 is the same one used with Sigil 2.3.0, so I would expect identical results. Any info on just how long Sigil had to stay running to get to the numbers you screen capped?

For the record... Sigil almost never needs very much GPU for rendering epubs. That's why we added the ability to turn off WebEngine's hardware acceleration in Sigil's preferences: to handle the edge cases where WebEngine doesn't always play nice with certain video cards. Have you tried disabling that?

[DiapDealer]

I'm not one to leave programs open and running for days at a time, but I'll leave Sigil running to see if I can duplicate your results. So far, my dedicated gpu memory is fluctuating between 0 and around 7,000K. But it's early. I'll keep checking.

[KevinH]

There is a bug posted to Qt about memory consumption with some AMD processors. I do not have a link handy but there are known issues.

I think I found the Qt bug report:

https://bugreports.qt.io/browse/QTBUG-125747

Using the --disable-gpu flag seemed to fix things. This did not happen with Intel.

[DiapDealer]

I'm testing on an AMD processor at home right now. But I'm away from it, so I'll have to report back later.

On the Intel laptop (integrated GPU) that I'm also testing on, all memory usage increases with use, but seems to settle back down to numbers that match what it launched with after some idle time. So no net increase that I've been able to find so far.

[DiapDealer]

It's not exactly the same as the OP's experience, but I'm seeing some strange results even on my Intel laptop with integrated GPU. When showing my shared GPU memory usage, I can make it steadily increase by simply minimizing and restoring Sigil over and over again. I got it up over a gigabyte and while it eventually went down a little, it never fully recovered (not even close).

This is all with the empty, default Sigil epub.

When I check the "Disable GPU Acceleration in QtWebEngine (in Sigil preferences), this behavior stops completely. The shared GPU memory usage stays nearly constant no matter how much minimizing and restoring I do.

Regular RAM usage stays fairly constant regardless of all of this.

[KevinH]

This is exactly what happened with the macOS memory leak Qt fixed earlier (but the fix was only for Apple Metal graphics). There was even a qml example program that opened a QtWebEngine WebEngineView and just constantly resized it, and you could watch the memory use just grow.

I will see if I can find the qml sample program and Qt bug.

Update: See https://bugreports.qt.io/browse/QTBUG-124353

In that issue is a bug.qml test case that you can run with the command:

qml bug.qml

and just watch the memory consumption grow due to huge memory leak. On arm64 mac the gpu and main memory s shared and you can see the gpu memory just grow.

It was fixed for MacOS in qt 6.7 with a patch.

Perhaps something similar is happening on Windows or Linux.