GTK display refresh rate is throttled

[Chen Zhang]

Guest OS running with GL enabled GTK display shows a reduced refresh rate, e.g. moving cursor around with iGVT-g DMA Buf.

Apparently, a default refresh interval GUI_REFRESH_INTERVAL_DEFAULT (30ms) is defined in include/ui/console.h, throttling the display refresh rate at 33Hz.

To correct this throttle issue, a shorter interval (16 or 17 milliseconds) should be applied to display change listener or the default value should be modified.

[Chen Zhang (cuser2)]

Slow motion clips for host/guest were uploaded as attachments.

[Thomas A. (agentlecomputer)]

Instead of changing the value, I think there should be a function that determines the ideal "GUI_REFRESH_INTERVAL_DEFAULT" value, with the option to override it. That way, monitor greater than 60 Hz can also benefit.

[Thomas Huth (th-huth)]

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]

[Jose Biosca (jbiosca)]

The bug is still here.

People are simply modifying the code and recompiling.. It only needs to change the code cap from 30ms (10 years old cap) to 16ms, and we got a smooth gui capable of gaming.

Please, don't ignore us. Recompiling qemu only for one number is very annoying.

[Thomas Huth (th-huth)]

The ticket has been re-opened here:

 https://gitlab.com/qemu-project/qemu/-/issues/700

... so let's keep this one here closed, please.