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    SubjectRE: [PATCH 1/8] perf/x86/intel: Fix memory corruption
    Date
    Attached cpu hotplug test output while perf is running in the background. No WARN messages seen.

    When I run the kexec command, it boots to bios. Haven't used kexec before. Still trying to figure that one out.

    -----Original Message-----
    From: Peter Zijlstra [mailto:peterz@infradead.org]
    Sent: Thursday, March 21, 2019 1:07 PM
    To: DSouza, Nelson <nelson.dsouza@intel.com>
    Cc: Tony Jones <tonyj@suse.com>; Thomas Gleixner <tglx@linutronix.de>; Stephane Eranian <eranian@google.com>; Ingo Molnar <mingo@kernel.org>; Jiri Olsa <jolsa@redhat.com>; LKML <linux-kernel@vger.kernel.org>
    Subject: Re: [PATCH 1/8] perf/x86/intel: Fix memory corruption

    On Thu, Mar 21, 2019 at 07:47:50PM +0000, DSouza, Nelson wrote:
    > Is the request to check whether the msr gets reset to default upon reboot of the machine ?

    basically:

    - apply patch
    - start workload with 4 counter (on all CPUs), such that tfa-msr=1
    - try the following:
    o cpu hotplug
    o kexec

    to see if the new WARN will trigger -- it should not.

    root@jf1-otc-3AR3-33:~# cat /sys/devices/cpu/allow_tsx_force_abort
    1
    root@jf1-otc-3AR3-33:~# perf stat -e cs,'{cache-misses,cache-references,branches,branch-misses}' --no-merge -a sleep 60 &
    [1] 3025
    root@jf1-otc-3AR3-33:~# echo 0 > /sys/devices/system/cpu/cpu4/online
    root@jf1-otc-3AR3-33:~# echo 0 > /sys/devices/system/cpu/cpu5/online
    root@jf1-otc-3AR3-33:~# echo 0 > /sys/devices/system/cpu/cpu6/online
    root@jf1-otc-3AR3-33:~# echo 0 > /sys/devices/system/cpu/cpu7/online
    root@jf1-otc-3AR3-33:~#
    Performance counter stats for 'system wide':

    4,800 cs
    <not counted> cache-misses
    <not counted> cache-references
    <not counted> branches
    <not counted> branch-misses

    60.009098150 seconds time elapsed



    [1]+ Done perf stat -e cs,'{cache-misses,cache-references,branches,branch-misses}' --no-merge -a sleep 60


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