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Subject: RE: ...\n
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From:   "Durrant, Paul" <pdurrant@amazon.co.uk>
To:     Peter Zijlstra <peterz@infradead.org>,
        "Allister, Jack" <jalliste@amazon.com>
CC:     "bp@alien8.de" <bp@alien8.de>,
        "diapop@amazon.co.uk" <diapop@amazon.co.uk>,
        "hpa@zytor.com" <hpa@zytor.com>,
        "jmattson@google.com" <jmattson@google.com>,
        "joro@8bytes.org" <joro@8bytes.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "metikaya@amazon.co.uk" <metikaya@amazon.co.uk>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "rkrcmar@redhat.com" <rkrcmar@redhat.com>,
        "sean.j.christopherson@intel.com" <sean.j.christopherson@intel.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "vkuznets@redhat.com" <vkuznets@redhat.com>,
        "wanpengli@tencent.com" <wanpengli@tencent.com>,
        "x86@kernel.org" <x86@kernel.org>
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Date:   Tue, 31 May 2022 14:52:04 +0000
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> -----Original Message-----
> From: Peter Zijlstra <peterz@infradead.org>
> Sent: 31 May 2022 15:44
> To: Allister, Jack <jalliste@amazon.com>
> Cc: bp@alien8.de; diapop@amazon.co.uk; hpa@zytor.com; jmattson@google.com=
; joro@8bytes.org;
> kvm@vger.kernel.org; linux-kernel@vger.kernel.org; metikaya@amazon.co.uk;=
 mingo@redhat.com;
> pbonzini@redhat.com; rkrcmar@redhat.com; sean.j.christopherson@intel.com;=
 tglx@linutronix.de;
> vkuznets@redhat.com; wanpengli@tencent.com; x86@kernel.org
> Subject: RE: [EXTERNAL]...\n
>=20
>=20
> On Tue, May 31, 2022 at 02:02:36PM +0000, Jack Allister wrote:
> > The reasoning behind this is that you may want to run a guest at a
> > lower CPU frequency for the purposes of trying to match performance
> > parity between a host of an older CPU type to a newer faster one.
>=20
> That's quite ludicrus. Also, then it should be the host enforcing the
> cpufreq, not the guest.

I'll bite... What's ludicrous about wanting to run a guest at a lower CPU f=
req to minimize observable change in whatever workload it is running?

  Paul