From: Gleb Natapov <gleb@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Brian Rak <brak@gameservers.com>, kvm@vger.kernel.org
Subject: Re: Windows Server 2008R2 KVM guest performance issues
Date: Tue, 27 Aug 2013 10:38:33 +0300 [thread overview]
Message-ID: <20130827073833.GD22899@redhat.com> (raw)
In-Reply-To: <521C52A8.40801@redhat.com>
On Tue, Aug 27, 2013 at 09:18:00AM +0200, Paolo Bonzini wrote:
> > I've captured 20,000 lines of kvm trace output. This can be found
> > https://gist.github.com/devicenull/fa8f49d4366060029ee4/raw/fb89720d34b43920be22e3e9a1d88962bf305da8/trace
>
> The guest is doing quite a lot of exits per second, mostly to (a) access
> the ACPI timer
I see a lot of PM timer access not ACPI timer. The solution for that is
the patchset Brian linked.
> (b) service NMIs. In fact, every NMI is reading the
> timer too and causing an exit to QEMU.
>
Do you mean "kvm_exit: reason EXCEPTION_NMI rip 0xfffff800016dcf84 info
0 80000307"? Those are not NMIs, single NMI will kill Windows, they are #NM
exceptions. Brian, is your workload uses floating point calculation?
> So it is also possible that you have to debug this inside the guest, to
> see if these exits are expected or not.
>
> Paolo
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--
Gleb.
next prev parent reply other threads:[~2013-08-27 7:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-26 19:15 Windows Server 2008R2 KVM guest performance issues Brian Rak
2013-08-26 22:01 ` Brian Rak
2013-08-27 7:18 ` Paolo Bonzini
2013-08-27 7:38 ` Gleb Natapov [this message]
2013-08-27 8:38 ` Paolo Bonzini
2013-08-27 8:44 ` Gleb Natapov
2013-08-27 14:09 ` Brian Rak
2013-08-27 14:44 ` Brian Rak
2013-08-27 15:09 ` Paolo Bonzini
2013-08-27 16:45 ` Brian Rak
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