Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-30 Thread Boris Ostrovsky
On 08/30/2016 11:22 AM, Sanghyun Hong wrote: >> As I said, this works for me for Xen guests. I thought perf kvm might >> check whether there is a KVM guest but it's not. The error message that >> you see is generated at the end of sampling if no samples are found. > > Oh, I see. I tried the same

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-30 Thread Sanghyun Hong
As I said, this works for me for Xen guests. I thought perf kvm might check whether there is a KVM guest but it's not. The error message that you see is generated at the end of sampling if no samples are found. Oh, I see. I tried the same command and check the contents of the perf.data.kvm file,

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-30 Thread Boris Ostrovsky
On 08/29/2016 08:12 PM, Sanghyun Hong wrote: > Hi Boris, > > /[Appreciate for your support, and I have one last question]/ > > Since we’re using the */Xen/* hypervisor (not the KVM that is > type-II), I think we cannot use the /*perf k*/*/vm/* command. Here are > the outputs: > > > #

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Sanghyun Hong
Yes, this will allow the hypervisor to collect samples from multiple guests. However, the tool (perf) probably won't be able to properly process these samples. But you can try. I understand, thus, I applied the patches and set the pmu_mode to all. However, I’m really curious what you mean by the

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Sanghyun Hong
Hi Boris, [Appreciate for your support, and I have one last question] Since we’re using the Xen hypervisor (not the KVM that is type-II), I think we cannot use the perf kvm command. Here are the outputs: # perf kvm --host --guest record -C 1 sleep 1 [ perf record: Woken up 1 times to

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Sanghyun Hong
I really appreciate for your answers. Last but not the least, I want to make it more clear: > The hypervisor will provide dom0 with a raw sample (guest's, dom0's or > hypervisor's) and then it's the job of dom0 kernel to properly tag and > format it and make it available to the userland (i.e.

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Sanghyun Hong
Hi Boris, I’ve found the documentations(https://github.com/torvalds/linux/blob/master/Documentation/ABI/testing/sysfs-hypervisor-pmu) in the kernel source code, and it seems like if we change the mode from self to all then we can collect counters for all the domains, right? All the best,

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Boris Ostrovsky
On 08/29/2016 05:48 PM, Sanghyun Hong wrote: > I really appreciate for your answers. Last but not the least, I want to make > it more clear: > >> The hypervisor will provide dom0 with a raw sample (guest's, dom0's or >> hypervisor's) and then it's the job of dom0 kernel to properly tag and >>

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Boris Ostrovsky
On 08/29/2016 05:08 PM, Sanghyun Hong wrote: >> Yes, this will allow the hypervisor to collect samples from multiple >> guests. However, the tool (perf) probably won't be able to properly >> process these samples. But you can try. > > I understand, thus, I applied the patches and set > the

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Boris Ostrovsky
On 08/29/2016 02:42 PM, Sanghyun Hong wrote: > Hi Boris, > > I’ve found the > documentations(https://github.com/torvalds/linux/blob/master/Documentation/ABI/testing/sysfs-hypervisor-pmu) > in the kernel source code, and it seems like if we change the mode > from *self* to *all* then we can

Re: [Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Boris Ostrovsky
On 08/29/2016 09:18 AM, Sanghyun Hong wrote: > Dear Xen-Devel Community: > > I’m a grad student working on measuring performance counters at the > Xen domains. I read this > thread(https://wiki.xenproject.org/wiki/Xen_Profiling:_oprofile_and_perf) in > web, and it says using Linux perf command

[Xen-devel] Questions about Using Perf at Dom0

2016-08-29 Thread Sanghyun Hong
Dear Xen-Devel Community: I’m a grad student working on measuring performance counters at the Xen domains. I read this thread(https://wiki.xenproject.org/wiki/Xen_Profiling:_oprofile_and_perf) in web, and it says using Linux perf command will let us collecting performance counters in both