[powerpc/merge] System crash during cpu offline/online operation

[powerpc/merge] System crash during cpu offline/online operation

[Sachin Sant]

I am observing system crash during a cpu offline/online operation
with latest merge branch code running in a PowerVM LPAR (P8 onwards)

# uname -r
5.10.0-rc7-01792-g244569c777ca
# ppc64_cpu --smt=1
[  244.205194] cpu 1 (hwid 1) Ready to die…
………
……...
[  247.015113] cpu 30 (hwid 30) Ready to die...
[  247.104973] cpu 31 (hwid 31) Ready to die…
# ppc64_cpu --smt=8

At this point the LPAR reboots instantly without any trace message.

IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM 
………..
………..
IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM 

          1 = SMS Menu                          5 = Default Boot List
          8 = Open Firmware Prompt              6 = Stored Boot List
          9 = Restricted Open Firmware Prompt

…….
…….

merge commit 9acd775e45 (based on rc6) was good. Mainline 5.10.0-rc7 also does
not exhibit this problem. 

Thanks
-Sachin
 

Re: [powerpc/merge] System crash during cpu offline/online operation

[Sachin Sant]

> On 11-Dec-2020, at 3:47 PM, Sachin Sant <sachinp@linux.vnet.ibm.com> wrote:
> 
> I am observing system crash during a cpu offline/online operation
> with latest merge branch code running in a PowerVM LPAR (P8 onwards)
> 
> # uname -r
> 5.10.0-rc7-01792-g244569c777ca
> # ppc64_cpu --smt=1
> [  244.205194] cpu 1 (hwid 1) Ready to die…
> ………
> ……...
> [  247.015113] cpu 30 (hwid 30) Ready to die...
> [  247.104973] cpu 31 (hwid 31) Ready to die…
> # ppc64_cpu --smt=8
> 
> At this point the LPAR reboots instantly without any trace message.

Git bisect leads me to the following commit:

3b47b7549ead0719e94022c6742199333c7c8d9f is the first bad commit
commit 3b47b7549ead0719e94022c6742199333c7c8d9f
Author: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Date:   Fri Nov 27 10:14:07 2020 +0530

    powerpc/book3s64/kuap: Move KUAP related function outside radix

Here is the bisect log:

# git bisect log
git bisect start
# bad: [244569c777ca638b08c75db88fe035bdec52ef80] Automatic merge of 'next' into merge (2020-12-10 00:34)
git bisect bad 244569c777ca638b08c75db88fe035bdec52ef80
# good: [9acd775e4579bde0a6d937d72f9669e418aa87ad] Automatic merge of 'master' into merge (2020-12-05 22:54)
git bisect good 9acd775e4579bde0a6d937d72f9669e418aa87ad
# good: [ab91292cb3e9f43d9c6839d7572d17b35bc21710] Merge tag 'char-misc-5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
git bisect good ab91292cb3e9f43d9c6839d7572d17b35bc21710
# bad: [19b311ca51e108b6d8d679496af8635fdc1984a8] ocxl: Initiate a TLB invalidate command
git bisect bad 19b311ca51e108b6d8d679496af8635fdc1984a8
# bad: [d94b827e89dc3f92cd871d10f4992a6bd3c861e5] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
git bisect bad d94b827e89dc3f92cd871d10f4992a6bd3c861e5
# good: [1d15ffdfc94127d75e04a88344ee1ce8c79f05fd] KVM: PPC: Book3S HV: Ratelimit machine check messages coming from guests
git bisect good 1d15ffdfc94127d75e04a88344ee1ce8c79f05fd
# good: [9f378b9f007cc94beadea40df83cc62a76975c6f] KVM: PPC: BOOK3S: PR: Ignore UAMOR SPR
git bisect good 9f378b9f007cc94beadea40df83cc62a76975c6f
# bad: [3b47b7549ead0719e94022c6742199333c7c8d9f] powerpc/book3s64/kuap: Move KUAP related function outside radix
git bisect bad 3b47b7549ead0719e94022c6742199333c7c8d9f
# good: [39df17bc20059c84ddc6f91831fce2e2cc79a6f3] powerpc/book3s64/kuap/kuep: Move uamor setup to pkey init
git bisect good 39df17bc20059c84ddc6f91831fce2e2cc79a6f3
# first bad commit: [3b47b7549ead0719e94022c6742199333c7c8d9f] powerpc/book3s64/kuap: Move KUAP related function outside radix

Thanks
-Sachin