mm/hugetlb: free cross-zone bootmem gigantic pages after allocation

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Now that hugetlb reservation runs after zone initialization, bootmem
gigantic page allocation can detect pages that span multiple zones.

Keep those cross-zone pages separate during allocation and free them after
allocation completes, so later hugetlb initialization only sees zone-valid
gigantic pages.

This chooses to free cross-zone gigantic pages directly instead of
retrying allocation.  In practice, such cross-zone cases are expected to
be very rare, so adding retry logic does not seem justified at this point.
Keeping the handling simple also preserves the previous behavior.  If
similar real-world reports show up later, retry support can be
reconsidered then.

Link: https://lore.kernel.org/20260612035903.2468601-15-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Oscar Salvador (SUSE) <osalvador@kernel.org>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

...

This commit is contained in:

Muchun Song 2026-06-12 11:58:58 +08:00 • committed by Andrew Morton

parent 27ca02e689

commit 20549ccf4d

1 changed files with 64 additions and 11 deletions

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mm/hugetlb.c

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