Performance degradation on showing huge content

[Xarlot]

While investigating WinUI 3 Desktop performance I`ve observed a performance degradation on showing new windows with huge content.

Describe the bug
Every new window with huge content shows 20% times slower compared to the previous.

Steps to reproduce the bug

1. Create a window with 1000 number boxes
2. Subscribe to Loaded event
3. Activate it
4. Repeat from step 1

Sample project App10.zip
Click a "click me" button, the result will be shown in the title.

Expected behavior
There is no difference between activations

Version Info
Package version 3.0.0-preview2.200713.0
AppModel WinUI 3 Desktop
OS Name Microsoft Windows 10 Enterprise
OS Version 10.0.19041 N/A Build 19041

[lhak]

I think have seen a similar issue (not sure if related) where the performance degrades after the window size was changed a few times. This could especially be seen with XAML animations.

[ranjeshj]

This might be related to this leak in cs/winrt. . @Xarlot can you check task manager and see if memory usage is increasing each time you activate ? @Scottj1s as FYI

[Xarlot]

It seems my steps to reproduce weren't good.
You should create and activate a new window each time. I`ve updated the description

[BorzillaR]

I upgrade the origin project to Preview 3. The performance issue still here.

Window num	Load time
1	5949
2	7242
3	9553
4	12310
5	15862

Each next window loads about 20% slower than the previous.

Updated project:
App10.zip

[stevenbrix]

Thanks @BorzillaR and @Xarlot.

@bartekk8 can you see if this is still reproing on the latest?

[JeanRoca]

@Austin-Lamb would someone on your team be able to look at this?

[bartekk8]

Thanks for reporting this issue. I verified and it still repros on the latest. The repro app creates multiple windows with a lot of content and in such case a slowdown is to be expected, but when windows are destroyed the perf should improve. Unfortunately, it doesn't, so It looks like there's a leak here! Again, thanks for catching it!

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 5 days.