No luck with qemu-kvm-ev, the behavior is the same. Running perf record -a
-g on the baremetal shows that most of the CPU time is in _raw_spin_lock
Children Self Command Shared Object Symbol
- 93.62% 93.62% qemu-kvm
[kernel.kallsyms] [k] _raw_spin_lock
- _raw_spin_lock
+ 45.30% kvm_mmu_sync_roots
+ 28.49% kvm_mmu_load
+ 25.00% mmu_free_roots
+ 1.12% tdp_page_fault
În joi, 18 aug. 2016 la 11:59, Laurentiu Soica <laurentiu at soica.ro> a scris:
> I've tried with KSM disabled and nothing changed.
>
> I've upgraded KVM to qemu-kvm-ev. I'm waiting to see if there are any
> improvements and report back.
>
> În mie., 17 aug. 2016 la 15:10, Boris Derzhavets <bderzhavets at hotmail.com>
> a scris:
>
>> For myself KSM is unpredictable feature. The problem is Compute, just
>> this node
>>
>> does "copy on write" , so only Compute.
>>
>> My concern exactly is where would it lead to worse or better Guest
>> behavior ?
>>
>> I am not expecting complete fix. I would track via top/htop and dmesg
>> via Cron on 1-2 hr
>>
>> period.
>>
>>
>> ------------------------------
>> *From:* centos-virt-bounces at centos.org <centos-virt-bounces at centos.org>
>> on behalf of Laurentiu Soica <laurentiu at soica.ro>
>> *Sent:* Wednesday, August 17, 2016 6:38 AM
>>
>> *To:* Discussion about the virtualization on CentOS
>> *Subject:* Re: [CentOS-virt] Nested KVM issue
>> Both baremetal and compute ? Are there any other metrics do you consider
>> useful to collect for troubleshooting purposes ?
>> În mie., 17 aug. 2016 la 13:04, Boris Derzhavets <bderzhavets at hotmail.com>
>> a scris:
>>
>>> It sounds weird, but attempt to disable KSM and see would it help or no ?
>>>
>>>
>>> ------------------------------
>>> *From:* centos-virt-bounces at centos.org <centos-virt-bounces at centos.org>
>>> on behalf of Laurentiu Soica <laurentiu at soica.ro>
>>> *Sent:* Wednesday, August 17, 2016 4:56 AM
>>>
>>> *To:* Discussion about the virtualization on CentOS
>>> *Subject:* Re: [CentOS-virt] Nested KVM issue
>>> Enabled the logging on both compute and baremetal. Nothing strange in
>>> logs:
>>>
>>> on baremetal :
>>> Wed Aug 17 11:51:01 EEST 2016: committed 62310764 free 58501808
>>> Wed Aug 17 11:51:01 EEST 2016: 87025667 < 123574516 and free > 24714903,
>>> stop ksm
>>>
>>> on compute:
>>> Wed Aug 17 08:52:52 UTC 2016: committed 24547132 free 76730936
>>> Wed Aug 17 08:52:52 UTC 2016: 45139624 < 102962460 and free > 20592492,
>>> stop ksm
>>>
>>> and the compute node is again at 100% CPU utilization.
>>>
>>>
>>>
>>> În mar., 16 aug. 2016 la 15:26, Boris Derzhavets <
>>> bderzhavets at hotmail.com> a scris:
>>>
>>>> I would enable ksmtuned logging ,if it has been done verify logs
>>>>
>>>>
>>>> ------------------------------
>>>> *From:* centos-virt-bounces at centos.org <centos-virt-bounces at centos.org>
>>>> on behalf of Laurentiu Soica <laurentiu at soica.ro>
>>>> *Sent:* Tuesday, August 16, 2016 7:16 AM
>>>>
>>>> *To:* Discussion about the virtualization on CentOS
>>>> *Subject:* Re: [CentOS-virt] Nested KVM issue
>>>> Yes. It is on both baremetal and compute node.
>>>>
>>>>
>>>> _______________________________________________
>>> CentOS-virt mailing list
>>> CentOS-virt at centos.org
>>> https://lists.centos.org/mailman/listinfo/centos-virt
>>>
>> _______________________________________________
>> CentOS-virt mailing list
>> CentOS-virt at centos.org
>> https://lists.centos.org/mailman/listinfo/centos-virt
>>
> --
Laurentiu Soica
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