Re: [PATCH] mapletree-vs-khugepaged

[Guenter Roeck]

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@xxxxxxxxxxxxx> [220513 10:46]:
> > > Heiko Carstens <hca@xxxxxxxxxxxxx> 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.

I finally found some time to bisect the alpha boot failures in -next.
Bisect results below.

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
# bad: [bbd9f664c351fbe61afa949abaaa03aed5c84af9] fs/proc/task_mmu: stop using linked list and highest_vm_end
git bisect bad bbd9f664c351fbe61afa949abaaa03aed5c84af9
# bad: [3b150cc8ab608f7a7da76b036b0ba7513628b0be] arm64: remove mmap linked list from vdso
git bisect bad 3b150cc8ab608f7a7da76b036b0ba7513628b0be
# good: [282a3e65bd1dece042bb8cf3a1666d79af1553b0] mm: use maple tree operations for find_vma_intersection()
git bisect good 282a3e65bd1dece042bb8cf3a1666d79af1553b0
# good: [d175d2cc268623e3e68181235a4aa068b50a8213] mm: convert vma_lookup() to use mtree_load()
git bisect good d175d2cc268623e3e68181235a4aa068b50a8213
# bad: [f1297d3a2cb77261c10fbbd69d92bbca700108e0] mm/mmap: reorganize munmap to use maple states
git bisect bad f1297d3a2cb77261c10fbbd69d92bbca700108e0
# good: [a897bb88e1e61df70f350a51f51cade3930adc3c] mm/mmap: move mmap_region() below do_munmap()
git bisect good a897bb88e1e61df70f350a51f51cade3930adc3c
# first bad commit: [f1297d3a2cb77261c10fbbd69d92bbca700108e0] mm/mmap: reorganize munmap to use maple states