Re: rcutorture’s init segfaults in ppc64le VM

[Paul Menzel]

Dear Michael,


Am 11.02.22 um 15:19 schrieb Paul Menzel:

> Am 11.02.22 um 02:48 schrieb Michael Ellerman:
>> Paul Menzel writes:
>>> Am 08.02.22 um 11:09 schrieb Michael Ellerman:
>>>> Paul Menzel writes:
>>>
>>> […]
>>>
>>>>> On the POWER8 server IBM S822LC running Ubuntu 21.10, building Linux
>>>>> 5.17-rc2+ with rcutorture tests
>>>>
>>>> I'm not sure if that's the host kernel version or the version you're
>>>> using of rcutorture? Can you tell us the sha1 of your host kernel 
>>>> and of the tree you're running rcutorture from?
>>>
>>> The host system runs Linux 5.17-rc1+ started with kexec. Unfortunately,
>>> I am unable to find the exact sha1.
>>>
>>>       $ more /proc/version
>>>       Linux version 5.17.0-rc1+ (x at eddb.molgen.mpg.de) (Ubuntu clang version 13.0.0-2, LLD 13.0.0) #1 SMP Fri Jan 28 17:13:04 CET 2022
>>
>> OK. In general rc1 kernels can have issues, so it might be worth
>> rebooting the host into either v5.17-rc3 or a distro or stable kernel.
>> Just to rule out any issues on the host.
> 
> Yes, that was a good test. It works with Ubuntu’s 5.13 Linux kernel.
> 
>      $ more /proc/version
>      Linux version 5.13.0-28-generic (buildd at bos02-ppc64el-013) (gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0, GNU ld (GNU Binutils for Ubuntu) 2.37) #31-Ubuntu SMP Thu Jan 13 17:40:19 UTC 2022
> 
> I have to do more tests, but it could be LLVM/clang related.

Building commit f1baf68e1383 (Merge tag 'net-5.17-rc4' of 
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net) with the ata 
patches on top with GCC, I am unable to reproduce the issue. Before I 
built it with

     make -j100 LLVM=1 LLVM_IAS=0 bindeb-pkg

[…]


Kind regards,

Paul