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| author | Vishal Moola (Oracle) <vishal.moola@gmail.com> | 2025-04-01 05:10:24 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-04-12 03:32:36 +0300 |
| commit | a84edd52f0a0fa193f0f685769939cf84510755b (patch) | |
| tree | e2fb77bd9a6dedd531416f81ab64fc84df12719f /drivers/fpga/tests/fpga-bridge-test.c | |
| parent | 770c8d55c42868239c748a3ebc57c9e37755f842 (diff) | |
| download | linux-a84edd52f0a0fa193f0f685769939cf84510755b.tar.xz | |
mm/compaction: fix bug in hugetlb handling pathway
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 commit 66fe1cf7f581 ("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: 369fa227c219 ("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>
Diffstat (limited to 'drivers/fpga/tests/fpga-bridge-test.c')
0 files changed, 0 insertions, 0 deletions