From: David Ahern <dsahern@gmail.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Mohamad Gebai <mohamad.gebai@polymtl.ca>,
kvm@vger.kernel.org, linux-perf-users@vger.kernel.org
Subject: Re: Tracing kvm: kvm_entry and kvm_exit
Date: Wed, 27 Feb 2013 21:49:24 -0700 [thread overview]
Message-ID: <512EE1D4.6080808@gmail.com> (raw)
In-Reply-To: <512E36B2.5090100@gmail.com>
On 2/27/13 9:39 AM, David Ahern wrote:
> I have been playing with the live mode a bit lately. I'll add a debug to
> note 2 consecutive entry events without an exit -- see if it sheds some
> light on it.
If you feel game take this for a spin:
https://github.com/dsahern/linux/commits/perf-kvm-live-3.8
I pushed a few more commits that add debugs to show consecutive events
(2 entries or 2 exits), max and min times for various exit reasons and
an option to dump events that take longer than some threshold. If you
dump the output to a file or run screen with logging you should be able
to find when the 'long' event happens and which VMEXIT reason was the cause.
Example screen dump:
21:47:37.935302
Analyze events for all VMs, all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max
Time Avg time
APIC_ACCESS 978 61.51% 0.02% 1us
113us 7.81us ( +- 3.67% )
IO_INSTRUCTION 212 13.33% 0.00% 2us
85us 9.20us ( +- 7.57% )
CR_ACCESS 93 5.85% 0.00% 2us
66us 3.49us ( +- 19.73% )
EXTERNAL_INTERRUPT 53 3.33% 0.01% 3us
135us 57.02us ( +- 6.59% )
EXCEPTION_NMI 26 1.64% 0.00% 2us
3us 2.57us ( +- 1.74% )
PENDING_INTERRUPT 3 0.19% 0.00% 1us
1us 1.85us ( +- 4.18% )
Total Samples:1590, Total events handled time:39942741.62us.
295170818723592 VM 11854, vcpu 3: APIC_ACCESS event took 113usec
295170819686668 VM 11854, vcpu 0: EXTERNAL_INTERRUPT event took 112usec
295172155051688 VM 11854, vcpu 0: EXTERNAL_INTERRUPT event took 119usec
295172841724899 VM 11854, vcpu 0: APIC_ACCESS event took 129usec
295172999633325 VM 11854, vcpu 0: EXTERNAL_INTERRUPT event took 111usec
David
next prev parent reply other threads:[~2013-02-28 4:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-22 16:34 Tracing kvm: kvm_entry and kvm_exit Mohamad Gebai
2013-02-25 10:18 ` Stefan Hajnoczi
2013-02-26 16:24 ` Mohamad Gebai
2013-02-26 16:32 ` Gleb Natapov
2013-02-27 16:39 ` David Ahern
2013-02-28 4:49 ` David Ahern [this message]
2013-02-28 8:44 ` Stefan Hajnoczi
2013-03-04 5:36 ` Mohamad Gebai
2013-03-04 5:40 ` David Ahern
2013-03-04 6:15 ` Mohamad Gebai
2013-03-05 17:23 ` David Ahern
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