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Date:   Wed, 16 Feb 2022 13:08:49 +0800
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Subject: Re: [PATCH kvm/queue v2 2/3] perf: x86/core: Add interface to query
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To:     "Liang, Kan" <kan.liang@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     Jim Mattson <jmattson@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
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        Wanpeng Li <wanpengli@tencent.com>,
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        linux-kernel@vger.kernel.org,
        Stephane Eranian <eranian@google.com>,
        David Dunn <daviddunn@google.com>,
        Dave Hansen <dave.hansen@intel.com>
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On 10/2/2022 11:34 pm, Liang, Kan wrote:
> For the current perf subsystem, a PMU should be shared among different users via 
> the multiplexing mechanism if the resource is limited. No one has full control 
> of a PMU for lifetime. A user can only have the PMU in its given period.

Off-topic, does perf has knobs to disable the default multiplexing mechanism
for individual tasks and enforce a first-come, first-served policy for same 
priority ?

The reported perf data from the multiplexing mechanism may even mislead
the conclusions of subsequent statistically based performance analysis.