[webkit-gtk] WK2/JSC idle wakeups and CPU utilisation

[Michael Gratton]

On Sun, Dec 3, 2017 at 8:02 PM, Carlos Garcia Campos 
<cgarcia at igalia.com> wrote:
> 
> 60 times per second and when visible sounds like the paint timer.

Yeah, same here. I attached a debug statement to the draw signal on the 
main window and that showed drawing going quiescent after a few seconds 
when application activity ceased, while the poll() churn continued. 
Shame gdk_window_set_debug_updates() doesn't seem to work any more.

>>   This seems to also occur for Epiphany,
>>  but not in other GTK+ apps such as Gitg, or Polari. Hence it looks
>>  like
>>  a WebKit2 issue.
> 
> Doesn't gitg use webkit2 as well?

I think it used to, but now uses GtkSourceView.

>>  Geary is setting
>>  WEBKIT_DISABLE_COMPOSITING_MODE=1 in main() right after launching,
>>  but
>>  commenting that out doesn't seem to make any difference.
> 
> Please don't do that, the env var is not expected to be used by
> applications, only for users/developers as a debug tool. Use
> webkit_settings_set_hardware_acceleration_policy() instead.

Yeah I know, I know, it's on my todolist.

> File bug report, please. If you can attach strace, sysprof, etc output
> and anything else that could help to identify the source of the wake
> ups.

Done! <https://bugs.webkit.org/show_bug.cgi?id=180330>

Cheers,
//Mike
-- 
⊨ Michael Gratton, Percept Wrangler.
⚙ <http://mjog.vee.net/>