Bug 256756

Summary:

[GTK] The stutters are back

Product:

WebKit

Reporter:

Kdwk <kdwkleung>

Component:

WebKitGTK

Assignee:

Carlos Garcia Campos <cgarcia>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

bugs-noreply, cgarcia, nekohayo

Priority:

Version:

WebKit Nightly Build

Hardware:

OS:

Linux

Bug Depends on:

Bug Blocks:

245783

Attachments:

Description	Flags
Screencast showing scrolling the same website in 2.40 VS 2.41	none
Output of webkit://gpu	none

Description Kdwk 2023-05-13 05:03:47 PDT

Created attachment 466343 [details]
Screencast showing scrolling the same website in 2.40 VS 2.41

With WebKitGTK 2.40, the stutters while scrolling heavy websites are largely gone. Even when the website doesn't respond it can still be scrolled smoothly (the scrollbar will usually lag behind the actual scrolling). However, with WebKitGTK 2.41, the stutters are back and the scrolling lags exactly the same as the scrollbar. See attached video for comparison. The URL used is https://www.reddit.com/r/nottheonion/comments/13fm9jv/loch_ness_monster_hunter_i_thought_this_job_would/, but the Reddit post must be opened from the main feed in order to reproduce the bug (go to reddit.com/r/nottheonion, the find this post, click to open comments, and scroll down).

Comment 1 Kdwk 2023-05-13 05:04:57 PDT

I should also mention that both are using the same number of painting threads (4) and the problem still occurs in MiniBrowser

Comment 2 Carlos Garcia Campos 2023-05-16 00:59:07 PDT

Does it happen with WEBKIT_DISABLE_DMABUF_RENDERER=1 too?

Comment 3 Kdwk 2023-05-17 00:50:31 PDT

Can confirm bug does not occur with WEBKIT_DISABLE_DMABUF_RENDERER=1

Comment 4 Carlos Garcia Campos 2023-05-17 02:16:59 PDT

Are you under X11 and GTK4? can you share the output of webkit://gpu?

Comment 5 Kdwk 2023-05-17 02:23:15 PDT

I am using Epiphany Technology Preview (GTK 4) on Gnome/ Wayland.

Comment 6 Kdwk 2023-05-17 02:23:35 PDT

Created attachment 466380 [details]
Output of webkit://gpu

Comment 7 Carlos Garcia Campos 2023-05-18 04:58:48 PDT

Pull request: https://github.com/WebKit/WebKit/pull/14012

Comment 8 Carlos Garcia Campos 2023-05-18 04:59:16 PDT

Could you try the patch in the PR, please?

Comment 9 Kdwk 2023-05-18 07:20:49 PDT

I applied the patch and compiled WebKitGTK. From testing in MiniBrowser, I believe the problem fixed now. Scrolling is now even smoother than 2.40

Comment 10 EWS 2023-05-19 00:37:01 PDT

Committed 264237@main (f8e938785f3c): <https://commits.webkit.org/264237@main>

Reviewed commits have been landed. Closing PR #14012 and removing active labels.