Thanks for the answer. I am more of an application user. Is there a
quick way to check this flag and enable it if its disabled?
Abhishek


On Mon, Oct 8, 2012 at 2:39 PM, Marcelo Tosatti <mtosa...@redhat.com> wrote:
> On Mon, Oct 08, 2012 at 02:55:25AM -0500, Abhishek Gupta wrote:
>> Hi,
>>
>> I am trying to get the steal time with 2 VMs (each with 1 Vcpu) pinned
>> to same core.
>>
>> While finding documentation on this, I came across your patches and
>> posts related to the implementation of this feature, so I thought it
>> would be best to ask you.
>>
>> I run the same application on these 2 VMs simultaneously and see the
>> performance difference. I am trying to read the steal time from inside
>> the guest using top, vmstat etc.
>>
>> Both, top and vmstat -s report the steal time (st) as 0. I also
>> checked that procps is in latest version. I am using virtio-net. I
>> suspect that the steal time is not being updated well. Is there
>> something which I need to configure for this to work? My Linux version
>> for guest image is:
>>
>> Linux server-147 2.6.35-24-virtual #42-Ubuntu SMP Thu Dec 2 05:15:26
>> UTC 2010 x86_64 GNU/Linux
>>
>> And /proc/cpuinfo shows i:
>>
>> processor     : 0
>> vendor_id     : GenuineIntel
>> cpu family    : 6
>> model         : 2
>> model name    : QEMU Virtual CPU version 0.14.0
>> stepping      : 3
>> cpu MHz               : 2992.498
>> cache size    : 4096 KB
>> fpu           : yes
>> fpu_exception : yes
>> cpuid level   : 4
>> wp            : yes
>> flags         : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
>> pse36 clflush mmx fxsr sse sse2 syscall nx lm up rep_good pni cx16
>> hypervisor lahf_lm
>  bogomips       : 5984.99
>> clflush size  : 64
>> cache_alignment       : 64
>> address sizes : 40 bits physical, 48 bits virtual
>> power management:
>>
>>
>> Another question I had was that is there a way to programmatically get
>> the value of steal cycles (e.g. from a  C program) ?
>> Thanks,
>>
>> Abhishek
>
> Make sure CONFIG_SCHEDSTATS is enabled in your host kernel.
>
>> On Monday, June 13, 2011 6:40:02 PM UTC-5, Glauber Costa wrote:
>> > Hi,
>> >
>> > This series is a repost of the last series I posted about this.
>> > It tries to address most concerns that were raised at the time,
>> > plus makes uses of the static_branch interface to disable the
>> > steal code when not in use.
>> >
>> >
>> > Glauber Costa (7):
>> >   KVM-HDR Add constant to represent KVM MSRs enabled bit
>> >   KVM-HDR: KVM Steal time implementation
>> >   KVM-HV: KVM Steal time implementation
>> >   KVM-GST: Add a pv_ops stub for steal time
>> >   KVM-GST: KVM Steal time accounting
>> >   KVM-GST: adjust scheduler cpu power
>> >   KVM-GST: KVM Steal time registration
>> >
>> >  Documentation/kernel-parameters.txt   |    4 ++
>> >  Documentation/virtual/kvm/msr.txt     |   33 +++++++++++++
>> >  arch/x86/Kconfig                      |   12 +++++
>> >  arch/x86/include/asm/kvm_host.h       |    8 +++
>> >  arch/x86/include/asm/kvm_para.h       |   15 ++++++
>> >  arch/x86/include/asm/paravirt.h       |    9 ++++
>> >  arch/x86/include/asm/paravirt_types.h |    1 +
>> >  arch/x86/kernel/kvm.c                 |   72 +++++++++++++++++++++++++++++
>> >  arch/x86/kernel/kvmclock.c            |    2 +
>> >  arch/x86/kernel/paravirt.c            |    9 ++++
>> >  arch/x86/kvm/x86.c                    |   60 +++++++++++++++++++++++-
>> >  kernel/sched.c                        |   81 
>> > +++++++++++++++++++++++++++++----
>> >  kernel/sched_features.h               |    4 +-
>> >  13 files changed, 296 insertions(+), 14 deletions(-)
>> >
>> > --
>> > 1.7.3.4
>> >
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> > the body of a message to majord...@vger.kernel.org
>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> > Please read the FAQ at  http://www.tux.org/lkml/
>>
>>
>>
>> On Monday, June 13, 2011 6:40:02 PM UTC-5, Glauber Costa wrote:
>> > Hi,
>> >
>> > This series is a repost of the last series I posted about this.
>> > It tries to address most concerns that were raised at the time,
>> > plus makes uses of the static_branch interface to disable the
>> > steal code when not in use.
>> >
>> >
>> > Glauber Costa (7):
>> >   KVM-HDR Add constant to represent KVM MSRs enabled bit
>> >   KVM-HDR: KVM Steal time implementation
>> >   KVM-HV: KVM Steal time implementation
>> >   KVM-GST: Add a pv_ops stub for steal time
>> >   KVM-GST: KVM Steal time accounting
>> >   KVM-GST: adjust scheduler cpu power
>> >   KVM-GST: KVM Steal time registration
>> >
>> >  Documentation/kernel-parameters.txt   |    4 ++
>> >  Documentation/virtual/kvm/msr.txt     |   33 +++++++++++++
>> >  arch/x86/Kconfig                      |   12 +++++
>> >  arch/x86/include/asm/kvm_host.h       |    8 +++
>> >  arch/x86/include/asm/kvm_para.h       |   15 ++++++
>> >  arch/x86/include/asm/paravirt.h       |    9 ++++
>> >  arch/x86/include/asm/paravirt_types.h |    1 +
>> >  arch/x86/kernel/kvm.c                 |   72 +++++++++++++++++++++++++++++
>> >  arch/x86/kernel/kvmclock.c            |    2 +
>> >  arch/x86/kernel/paravirt.c            |    9 ++++
>> >  arch/x86/kvm/x86.c                    |   60 +++++++++++++++++++++++-
>> >  kernel/sched.c                        |   81 
>> > +++++++++++++++++++++++++++++----
>> >  kernel/sched_features.h               |    4 +-
>> >  13 files changed, 296 insertions(+), 14 deletions(-)
>> >
>> > --
>> > 1.7.3.4
>> >
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> > the body of a message to majord...@vger.kernel.org
>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> > Please read the FAQ at  http://www.tux.org/lkml/
>> --
>> To unsubscribe from this list: send the line "unsubscribe kvm" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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