Skip to content

Commit

Permalink
mm: migrate: use thp_order instead of HPAGE_PMD_ORDER for new page al…
Browse files Browse the repository at this point in the history
…location.

Fix a VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages) crash.

With folios support, it is possible to have other than HPAGE_PMD_ORDER
THPs, in the form of folios, in the system.  Use thp_order() to correctly
determine the source page order during migration.

Link: https://lkml.kernel.org/r/20220404165325.1883267-1-zi.yan@sent.com
Link: https://lore.kernel.org/linux-mm/20220404132908.GA785673@u2004/
Fixes: d68ecca ("mm/filemap: Allow large folios to be added to the page cache")
Reported-by: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
x-y-z authored and torvalds committed Apr 9, 2022
1 parent d00c50b commit a04cd16
Show file tree
Hide file tree
Showing 2 changed files with 2 additions and 2 deletions.
2 changes: 1 addition & 1 deletion mm/mempolicy.c
Original file line number Diff line number Diff line change
Expand Up @@ -1209,7 +1209,7 @@ static struct page *new_page(struct page *page, unsigned long start)
struct page *thp;

thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
HPAGE_PMD_ORDER);
thp_order(page));
if (!thp)
return NULL;
prep_transhuge_page(thp);
Expand Down
2 changes: 1 addition & 1 deletion mm/migrate.c
Original file line number Diff line number Diff line change
Expand Up @@ -1547,7 +1547,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
*/
gfp_mask &= ~__GFP_RECLAIM;
gfp_mask |= GFP_TRANSHUGE;
order = HPAGE_PMD_ORDER;
order = thp_order(page);
}
zidx = zone_idx(page_zone(page));
if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE)
Expand Down

0 comments on commit a04cd16

Please sign in to comment.