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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Wed, 12 Oct 2022 09:12:32 -0700
Message-ID: <CAM9d7chpXGm9vDf4qN0JQQWdgWDNR05vPuqnDo4=F2jWdo0S3A@mail.gmail.com>
Subject: Re: [PATCH V2 2/6] perf/x86/intel/pebs: Fix PEBS timestamps overwritten
To:     Peter Zijlstra <peterz@infradead.org>,
        Kan Liang <kan.liang@linux.intel.com>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Stephane Eranian <eranian@google.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Andi Kleen <ak@linux.intel.com>, andreas.kogler.0x@gmail.com,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        Ravi Bangoria <ravi.bangoria@amd.com>
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Hi Peter,

On Wed, Oct 12, 2022 at 1:05 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Tue, Oct 11, 2022 at 11:20:54AM -0700, Namhyung Kim wrote:
>
> > One thing I noticed is that the system has a config option
> > CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y.
>
> You can't build x86 without that.

Oh, I didn't know that..  so it's not a config problem.

Kan, could you check the following command?

  $ perf record -e cycles:upp dd if=/dev/zero of=/dev/null count=10000

Thanks,
Namhyung