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:[email protected]]
Sent: Thursday, March 21, 2019 1:07 PM
To: DSouza, Nelson <[email protected]>
Cc: Tony Jones <[email protected]>; Thomas Gleixner <[email protected]>; Stephane
Eranian <[email protected]>; Ingo Molnar <[email protected]>; Jiri Olsa
<[email protected]>; LKML <[email protected]>
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
