Red Hat Bugzilla – Bug 1017644
PATCH: fix qemu using 50% host cpu when audio is playing
Last modified: 2013-11-16 01:54:24 EST
qemu-1.2 and later (so F-18+) have a regression where the audio_timer tries to expires every nano second, which gets rate limited to every 250 us by the timer subsys, resulting in 4000 wakeups per seconds for vms with audio active.
Here is an upstream patch fixing this:
Dropping host cpu load to a much better 13%. And here is a follow up patch further limiting the wakeup rate from 250 / second (which is a bit much) to 100 / second:
Further reducing the host cpu load for playing audio to 9%.
Note master had some timer functions renamed, so the 1st patch won't apply as is, backporting it is trivial though.
Since only the first patch is upstream right now and seems the most important one, I'll just pull that.
qemu-1.6.1-1.fc20 has been submitted as an update for Fedora 20.
(In reply to Cole Robinson from comment #1)
> Since only the first patch is upstream right now and seems the most
> important one, I'll just pull that.
* should fix your issue,
* was pushed to the Fedora 20 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing qemu-1.6.1-1.fc20'
as soon as you are able to.
Please go to the following url:
then log in and leave karma (feedback).
qemu-1.6.1-1.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.