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a84edd52f0
The compaction code doesn't take references on pages until we're certain we should attempt to handle it. In the hugetlb case, isolate_or_dissolve_huge_page() may return -EBUSY without taking a reference to the folio associated with our pfn. If our folio's refcount drops to 0, compound_nr() becomes unpredictable, making low_pfn and nr_scanned unreliable. The user-visible effect is minimal - this should rarely happen (if ever). Fix this by storing the folio statistics earlier on the stack (just like the THP and Buddy cases). Also revert commit66fe1cf7f5("mm: compaction: use helper compound_nr in isolate_migratepages_block") to make backporting easier. Link: https://lkml.kernel.org/r/20250401021025.637333-1-vishal.moola@gmail.com Fixes:369fa227c2("mm: make alloc_contig_range handle free hugetlb pages") Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
3376 lines
93 KiB
3376 lines
93 KiB