From: Dennis Jacobfeuerborn <dennisml@conversis.de>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] qemu-kvm idle guest using 10% cpu and causes significant increase of read_hpet calls on host
Date: Sat, 30 Jul 2011 15:14:48 +0200 [thread overview]
Message-ID: <4E3403C8.7080405@conversis.de> (raw)
Hi,
I've started running a Centos6 minimal install virtual machine on a
Centost6 host and noticed that even when the guest is completely idle the
qemu-kvm process on the host shows up with 10% cpu usage on in "top".
Using perf and oprofile I noticed that once the guest is running the amount
of read_hpet calls increases by a factor of 10. So I went and booted the
host with "hpet=disable" which resulted in the qemu-kvm process now showing
up with 15% cpu usage instead of 10%. So this seems to have an impact but
certainly not the intended one.
I'm not well versed in these matters so I'm looking for any pointers in
terms of for example kernel options I could test on the guest/host to find
out what the cause of this is.
I opened a bug here:
http://bugs.centos.org/view.php?id=5028
According to one developer this is also seen by users on RHEL6 and SL6
which is why I decided to ask for help here since it doesn't seem to be a
distribution specific problem.
Regards,
Dennis
reply other threads:[~2011-07-30 13:14 UTC|newest]
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