diff options
| author | Zi Yan <ziy@nvidia.com> | 2022-05-26 19:15:31 -0400 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-05-27 09:33:43 -0700 |
| commit | 86d28b0709279ccc636ef9ba267b7f3bcef79a4b (patch) | |
| tree | 3d9a9a1eb1b438d7d01b6754540a4f25598658f0 /mm/page_isolation.c | |
| parent | 9b209e557d698f24317d2619d8628b98b6728e4f (diff) | |
| download | linux-86d28b0709279ccc636ef9ba267b7f3bcef79a4b.tar.bz2 | |
mm: split free page with properly free memory accounting and without race
In isolate_single_pageblock(), free pages are checked without holding zone
lock, but they can go away in split_free_page() when zone lock is held.
Check the free page and its order again in split_free_page() when zone lock
is held. Recheck the page if the free page is gone under zone lock.
In addition, in split_free_page(), the free page was deleted from the page
list without changing free page accounting. Add the missing free page
accounting code.
Fix the type of order parameter in split_free_page().
Link: https://lore.kernel.org/lkml/20220525103621.987185e2ca0079f7b97b856d@linux-foundation.org/
Link: https://lkml.kernel.org/r/20220526231531.2404977-2-zi.yan@sent.com
Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: Doug Berger <opendmb@gmail.com>
Link: https://lore.kernel.org/linux-mm/c3932a6f-77fe-29f7-0c29-fe6b1c67ab7b@gmail.com/
Cc: David Hildenbrand <david@redhat.com>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Eric Ren <renzhengeek@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michael Walle <michael@walle.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_isolation.c')
| -rw-r--r-- | mm/page_isolation.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index fbd820b21292..6021f8444b5a 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -371,9 +371,13 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags, if (PageBuddy(page)) { int order = buddy_order(page); - if (pfn + (1UL << order) > boundary_pfn) - split_free_page(page, order, boundary_pfn - pfn); - pfn += (1UL << order); + if (pfn + (1UL << order) > boundary_pfn) { + /* free page changed before split, check it again */ + if (split_free_page(page, order, boundary_pfn - pfn)) + continue; + } + + pfn += 1UL << order; continue; } /* |