Messages in this thread | | | Date | Sun, 15 Jul 2012 16:03:23 +0300 | From | Avi Kivity <> | Subject | Re: perf with precise attribute kills all KVM based VMs |
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On 07/15/2012 04:00 PM, David Ahern wrote: > On 7/15/12 2:07 AM, Avi Kivity wrote: >> On 07/12/2012 07:06 PM, Gleb Natapov wrote: >>>> >>>> Note the :pH this time. >>> I am not sure what perf kvm does with :pH modifier, but H modifier does >>> not make sense with perf kvm and should be reported as an error by >>> perf tool. >> >> Maybe it should refer to the guest vs. the nested guest... > > :H = host mode; you are thinking of :h for hypervisor mode. From > perf-list documentation: > > "Modifiers allow the user to restrict when events are > counted with 'u' for user-space, 'k' for kernel, 'h' for hypervisor. > Additional modifiers are 'G' for guest counting (in KVM guests) and 'H' > for host counting (not in KVM guests)."
No, it's an additional distinction. A kvm guest can be in kernel mode, user mode, or in a nested guest mode (which has its own user mode and kernel mode). Currently we have no way of distinguishing between guest kernel mode and nested guest kernel mode.
I assume 'h' means profiling the hypervisor from a guest (i.e. xen dom0)?
-- error compiling committee.c: too many arguments to function
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