Bug 250829 – [GTK] MiniBrowser takes 12s to render https://www.wikipedia.org

• Component: WebKitGTK
• Status: NEW

[Antonio]

# Platform:

- Ubuntu 22.04
- uname -srvmpio: Linux 5.15.0-10057-tuxedo #63tux3 SMP Thu Jan 12 14:42:43 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
- AMD Ryzen 7 5700U with Radeon Graphics / 64Gb RAM

# WebKitGTK versions

Happens on both
- libwebkit2gtk-4.0-37:amd64                       2.38.3-0ubuntu0.22.04.1                 amd64        Web content engine library for GTK
- libwebkit2gtk-4.1-0:amd64                        2.38.3-0ubuntu0.22.04.1                 amd64        Web content engine library for GTK

# Steps to reproduce:

1. Open https://www.wikipedia.org in MiniBrowser

$ /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/MiniBrowser https://www.wikipedia.org/

The system goes to 100% CPU on one of the cores during about 12 seconds. The core with high CPU changes over time. 

- MiniBrowser seems unresponsive while loading (resizing the window does not resize the webview).
- Once the page loads, resizing MiniBrowser's window seems to do some flickering, high CPU consumption. 
- NOTE: This page has several SVG images.

2. Close MiniBrowser and reopen with url https://webkitgtk.org/

$ /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/MiniBrowser https://webkitgtk.org/

- The page loads very fast.
- No observable flickering when resizing the window. Less CPU consumption.

3. Close MiniBrowser and reopen with url https://github.com/

$ /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/MiniBrowser https://github.com/

- The page loads not so fast, CPU has a 40-60% spike.
- Some observable flickering when resizing the window (webview resizing lags when resizing horizontally).

# Expected behaviour

All pages should load quickly :-).

[Claudio Saavedra]

> 1. Open https://www.wikipedia.org in MiniBrowser
> 
> $ /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/MiniBrowser
> https://www.wikipedia.org/
> 
> The system goes to 100% CPU on one of the cores during about 12 seconds. The
> core with high CPU changes over time. 
> 
> - MiniBrowser seems unresponsive while loading (resizing the window does not
> resize the webview).
> - Once the page loads, resizing MiniBrowser's window seems to do some
> flickering, high CPU consumption. 
> - NOTE: This page has several SVG images.

I remember that loading the landing page of Wikipedia was particularly slow due to one of the SVGs that is (IIRC) embedded as a data url in the main document. I don't remember the details and I might not have filed a bug about it, so that might be the slowdown you see. I didn't analyze it further though.

As for the other issues, I don't think it's going to be possible to track everything in the same bug report, as they are not necessaarily the same issues. And "all pages should load quickly" is not an actionable task.

[Antonio]

Thanks for a quick reply, Claudio.

I'm not particularly interested in that web page in particular. It just happened by accident that I set it to the main page of my app, and I was concerned that I was doing something wrong in my code.

The fact is that my app works pretty well with any other web page, so I must be doing things right :-D.

Feel free to close this bug report, then. 

Cheers,
Antonio

[Michael Catanzaro]

Let's focus this bug on wikipedia.org only.

It's possibly related to bug #247748, although maybe not, because I'm consistently able to load Wikipedia in only 3 seconds.