On Tue, 12 Dec 2023, Peter Maydell wrote:
On Tue, 12 Dec 2023 at 18:46, BALATON Zoltan <bala...@eik.bme.hu> wrote:
On Tue, 12 Dec 2023, Marek Glogowski wrote:
Additionally, how can I use this message on qemu-devel.
It has a post for people who use Macos or Asahi Linux. Verify random qemu
sessions under Macos .Some are faster others are slow.
The topic is posted on qemu-disc...@nongnu.org (I don't know if developers
look there often)
https://lists.nongnu.org/archive/html/qemu-discuss/2023-12/msg00008.html
The program posted there was prepared by one of the maintainers of ppc qemu
machines "BALATON Zoltan".
We are starting to gather as much information as possible for it.
I hope nobody will be offended about this information in this topic. I do
not want to start a topic and litter other lists
It's better to do that in a separate thead, I've changed the subject
accordingly. I only came up with the idea and scripted it but the actual
test case comes from Marek and the original report from Rene Engel.
This problem was first seen running AmigaOS with qemu-system-ppc but then
we also reproduced it with Linux guest with the test in the qemu-discuss
messgage linked above. The runs are not exactly random but there seem to
be slow and fast sessions with the slow one about half the expected speed.
If we get a fast or slow session seems to be random. This was seen on
Apple M1 and Apple M1 Max under macOS but could not reproduce on x86_64
host under Linux or Apple M2 host under Linux so it may either be related
to Apple M1 or macOS host.
Is this possibly related to https://gitlab.com/qemu-project/qemu/-/issues/334
where App Nap is reported as causing QEMU to slow down when the window
doesn't have focus, or does it happen even when the QEMU window has
focus the whole time the benchmark is running ?
Yes, the original test which found it was running Quake timedemo on
AmgiaOS with QEMU running in foreground and that does a lot of what is
listed to prevent App Nap such as playing sound and doing graphics. Also
the sessions are either fast or slow from the start, they don't start fast
then become slow but sometimes run fast while most of the time they are
slow and this happens randomly when starting the same command multiple
times in a row as the scripted test that runs lame to encode mp3 with
Linux guest does. So this does not seem related to App Nap to me. It did
not seem to happen on Linux host even on Apple M2 but more testing with
those might be needed to confirm that.
Regards,
BALATON Zoltan
