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@xxxxxxxx> 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@xxxxxxxxxxx> 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@xxxxxxxxxx <centos-virt-bounces@xxxxxxxxxx> on behalf of Laurentiu Soica <laurentiu@xxxxxxxx>
Sent: Wednesday, August 17, 2016 6:38 AM
To: Discussion about the virtualization on CentOS
Subject: Re: 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@xxxxxxxxxxx> a scris:
It sounds weird, but attempt to disable KSM and see would it help or no ?
From: centos-virt-bounces@xxxxxxxxxx <centos-virt-bounces@xxxxxxxxxx> on behalf of Laurentiu Soica <laurentiu@xxxxxxxx>
Sent: Wednesday, August 17, 2016 4:56 AM
To: Discussion about the virtualization on CentOS
Subject: Re: 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 58501808Wed 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 76730936Wed 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@xxxxxxxxxxx> a scris:
I would enable ksmtuned logging ,if it has been done verify logs
From: centos-virt-bounces@xxxxxxxxxx <centos-virt-bounces@xxxxxxxxxx> on behalf of Laurentiu Soica <laurentiu@xxxxxxxx>
Sent: Tuesday, August 16, 2016 7:16 AM
To: Discussion about the virtualization on CentOS
Subject: Re: Nested KVM issueYes. It is on both baremetal and compute node.
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