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authorZi Yan <ziy@nvidia.com>2022-05-30 22:44:50 -0400
committerakpm <akpm@linux-foundation.org>2022-06-01 15:57:16 -0700
commit547be963c99f1e9ebc1cfabf630f64601a98dd00 (patch)
tree052f20809627f139d0588a42a275b2a8d8e9709e
parent0111def915b280c64c05f73f01b59ca404255aa3 (diff)
downloadlwn-547be963c99f1e9ebc1cfabf630f64601a98dd00.tar.gz
lwn-547be963c99f1e9ebc1cfabf630f64601a98dd00.zip
mm: page_isolation: use compound_nr() correctly in isolate_single_pageblock()
When compound_nr(page) was used, page was not guaranteed to be the head of the compound page and it could cause an infinite loop. Fix it by calling it on the head page. Link: https://lkml.kernel.org/r/20220531024450.2498431-1-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: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/linux-mm/20220530115027.123341-1-anshuman.khandual@arm.com/ Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Muchun Song <songmuchun@bytedance.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: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/page_isolation.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 6021f8444b5a..d200d41ad0d3 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -385,9 +385,9 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
* above do the rest. If migration is not possible, just fail.
*/
if (PageCompound(page)) {
- unsigned long nr_pages = compound_nr(page);
struct page *head = compound_head(page);
unsigned long head_pfn = page_to_pfn(head);
+ unsigned long nr_pages = compound_nr(head);
if (head_pfn + nr_pages <= boundary_pfn) {
pfn = head_pfn + nr_pages;