Re: + mm-initialize-struct-pages-in-reserved-regions-outside-of-the-zone-ranges.patch added to -mm tree

[David Hildenbrand <david@redhat.com>]

On 06.12.20 01:54, akpm@linux-foundation.org wrote:
> 
> The patch titled
>      Subject: mm: initialize struct pages in reserved regions outside of the zone ranges
> has been added to the -mm tree.  Its filename is
>      mm-initialize-struct-pages-in-reserved-regions-outside-of-the-zone-ranges.patch
> 
> This patch should soon appear at
>     https://ozlabs.org/~akpm/mmots/broken-out/mm-initialize-struct-pages-in-reserved-regions-outside-of-the-zone-ranges.patch
> and later at
>     https://ozlabs.org/~akpm/mmotm/broken-out/mm-initialize-struct-pages-in-reserved-regions-outside-of-the-zone-ranges.patch
> 
> Before you just go and hit "reply", please:
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>    c) Ideally: find the original patch on the mailing list and do a
>       reply-to-all to that, adding suitable additional cc's
> 
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
> 
> The -mm tree is included into linux-next and is updated
> there every 3-4 working days
> 
> ------------------------------------------------------
> From: Andrea Arcangeli <aarcange@redhat.com>
> Subject: mm: initialize struct pages in reserved regions outside of the zone ranges
> 
> Without this change, the pfn 0 isn't in any zone spanned range, and it's
> also not in any memory.memblock range, so the struct page of pfn 0 wasn't
> initialized and the PagePoison remained set when reserve_bootmem_region
> called __SetPageReserved, inducing a silent boot failure with DEBUG_VM
> (and correctly so, because the crash signaled the nodeid/nid of pfn 0
> would be again wrong).
> 
> There's no enforcement that all memblock.reserved ranges must overlap
> memblock.memory ranges, so the memblock.reserved ranges also require an
> explicit initialization and the zones ranges need to be extended to
> include all memblock.reserved ranges with struct pages too or they'll be
> left uninitialized with PagePoison as it happened to pfn 0.
> 
> Link: https://lkml.kernel.org/r/20201205013238.21663-2-aarcange@redhat.com
> Fixes: 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Qian Cai <cai@lca.pw>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

[...]

I've lost track which patches are we considering right now to solve the
overall issue. I'd appreciate a proper patch series with all relevant
patches.

-- 
Thanks,

David / dhildenb