Re: [PATCH] mapletree-vs-khugepaged

[Guenter Roeck <linux@roeck-us.net>]

On 5/17/22 04:53, Heiko Carstens wrote:
> On Fri, May 13, 2022 at 05:00:31PM +0000, Liam Howlett wrote:
>> * Sven Schnelle <svens@linux.ibm.com> [220513 10:46]:
>>> Heiko Carstens <hca@linux.ibm.com> writes:
>>>> FWIW, same on s390 - linux-next is completely broken. Note: I didn't
>>>> bisect, but given that the call trace, and even the failing address
>>>> match, I'm quite confident it is the same reason.
>>> IS that issue supposed to be fixed? git bisect pointed me to
>>>
>>> # bad: [76535d42eb53485775a8c54ea85725812b75543f] Merge branch
>>>    'mm-everything' of
>>>    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>>>
>>> which isn't really helpful.
>>>
>>> Anything we could help with debugging this?
>>
>> I tested the maple tree on top of the s390 as it was the same crash and
>> it was okay.  I haven't tested the mm-everything branch though.  Can you
>> test mm-unstable?
>>
>> I'll continue setting up a sparc VM for testing here and test
>> mm-everything on that and the s390
> 
> So due to reports here I did some sort of "special bisect": with today's
> linux-next I did a hard reset to commit 562340595cbb ("Merge branch
> 'for-next/kspp' of
> git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git"),
> started a bisect on Andrew's tree between mm-stable and mm-unstable, and
> merged whatever commit was about to be bisected into 562340595cbb.
> 
> This lead finally to commit f1297d3a2cb7 ("mm/mmap: reorganize munmap to
> use maple states") as "first bad commit".
> 
> So given that we are shortly before the merge window and linux-next is
> completely broken for s390, how do we proceed? Right now I have no idea if
> there is anything else in linux-next that would break s390 because of this.
> 
> Even though I'm sure you won't like to hear this, but I'd appreciate if
> this code could be removed from linux-next again.

Another bisect result, boot failures with nommu targets (arm:mps2-an385,
m68k:mcf5208evb). Bisect log is the same for both.

Guenter

---
# bad: [47c1c54d1bcd0a69a56b49473bc20f17b70e5242] Add linux-next specific files for 20220517
# good: [42226c989789d8da4af1de0c31070c96726d990c] Linux 5.18-rc7
git bisect start 'HEAD' 'v5.18-rc7'
# good: [27d9fca0814b912f762dd5adeb81d9ab250705a9] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git
git bisect good 27d9fca0814b912f762dd5adeb81d9ab250705a9
# good: [c57a4cecd8f02b365109fc326c7cde5ec6020a54] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
git bisect good c57a4cecd8f02b365109fc326c7cde5ec6020a54
# good: [0389ffdcdd4eacf5cfcef2a5e25b49a1662f8a8b] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git
git bisect good 0389ffdcdd4eacf5cfcef2a5e25b49a1662f8a8b
# good: [c506c5c327711f8bb522c10262ec3a932fe91cd2] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git
git bisect good c506c5c327711f8bb522c10262ec3a932fe91cd2
# bad: [b24964a75c5c0129fd6a0d9bcb0fb6e84fbac126] mm/mmap: drop range_has_overlap() function
git bisect bad b24964a75c5c0129fd6a0d9bcb0fb6e84fbac126
# good: [3cbab4ca1ea8752912d8719d72059869b4c18045] mm/damon/sysfs: use enum for 'state' input handling
git bisect good 3cbab4ca1ea8752912d8719d72059869b4c18045
# good: [9113eaf331bf44579882c001867773cf1b3364fd] mm/memory-failure.c: add hwpoison_filter for soft offline
git bisect good 9113eaf331bf44579882c001867773cf1b3364fd
# good: [2b2adc303cebc213072520eb2e86e4beb65e9499] mm: remove rb tree.
git bisect good 2b2adc303cebc213072520eb2e86e4beb65e9499
# good: [bbd9f664c351fbe61afa949abaaa03aed5c84af9] fs/proc/task_mmu: stop using linked list and highest_vm_end
git bisect good bbd9f664c351fbe61afa949abaaa03aed5c84af9
# good: [e09906217c535bd7c2e4eb35182543214c4b8891] mm/mempolicy: use vma iterator & maple state instead of vma linked list
git bisect good e09906217c535bd7c2e4eb35182543214c4b8891
# good: [0154775a4cf2bc79c2220207816c86142f259e95] mm/pagewalk: use vma_find() instead of vma linked list
git bisect good 0154775a4cf2bc79c2220207816c86142f259e95
# bad: [bd773a78705fb58eeadd80e5b31739df4c83c559] nommu: remove uses of VMA linked list
git bisect bad bd773a78705fb58eeadd80e5b31739df4c83c559
# good: [387141902a1de92a387816ae819d6111e582c6eb] i915: use the VMA iterator
git bisect good 387141902a1de92a387816ae819d6111e582c6eb
# first bad commit: [bd773a78705fb58eeadd80e5b31739df4c83c559] nommu: remove uses of VMA linked list