Re: [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit
From: Yang Shi <hidden>
Date: 2021-07-28 23:44:30
On Tue, Jul 27, 2021 at 9:25 PM Aneesh Kumar K.V [off-list ref] wrote:
Similar to commit 2da9f6305f30 ("mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit")
avoid using unsigned int for nr_pages. With unsigned int type the large
unsigned int converts to a large positive signed long.
Symptoms include CMA allocations hanging forever
due to alloc_contig_range->...->isolate_migratepages_block waiting
forever in "while (unlikely(too_many_isolated(pgdat)))".
Fixes: c5fc5c3ae0c8 ("mm: migrate: account THP NUMA migration counters correctly")
Cc: Yang Shi <redacted>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <redacted>It seems Andrew picked this one. Either one is fine to me. Reviewed-by: Yang Shi <redacted>
quoted hunk ↗ jump to hunk
--- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/mm/migrate.c b/mm/migrate.c index 34a9ad3e0a4f..7e240437e7d9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c@@ -2068,7 +2068,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, LIST_HEAD(migratepages); new_page_t *new; bool compound; - unsigned int nr_pages = thp_nr_pages(page); + int nr_pages = thp_nr_pages(page); /* * PTE mapped THP or HugeTLB page can't reach here so the page could --2.31.1