On 1/6/23 6:54 PM, Mike Kravetz wrote:
On 01/03/23 13:13, Sidhartha Kumar wrote:
Change alloc_huge_page_nodemask() to alloc_hugetlb_folio_nodemask() and
alloc_migrate_huge_page() to alloc_migrate_hugetlb_folio(). Both functions
now return a folio rather than a page.
/* mempolicy aware migration callback */
@@ -2357,16 +2357,16 @@ struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
{
struct mempolicy *mpol;
nodemask_t *nodemask;
- struct page *page;
+ struct folio *folio;
gfp_t gfp_mask;
int node;
gfp_mask = htlb_alloc_mask(h);
node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
- page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
+ folio = alloc_hugetlb_folio_nodemask(h, node, nodemask, gfp_mask);
mpol_cond_put(mpol);
- return page;
+ return &folio->page;
Is it possible that folio could be NULL here and cause addressing exception?
diff --git a/mm/migrate.c b/mm/migrate.c
index 6932b3d5a9dd..fab706b78be1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1622,6 +1622,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
struct migration_target_control *mtc;
gfp_t gfp_mask;
unsigned int order = 0;
+ struct folio *hugetlb_folio = NULL;
struct folio *new_folio = NULL;
int nid;
int zidx;
@@ -1636,7 +1637,9 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
struct hstate *h = folio_hstate(folio);
gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
- return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
+ hugetlb_folio = alloc_hugetlb_folio_nodemask(h, nid,
+ mtc->nmask, gfp_mask);
+ return &hugetlb_folio->page;
and, here as well?
Hi Mike,
It is possible that the folio could be null but I believe these
instances would not cause an addressing exception because as described
in [1], &folio->page is safe even if the folio is NULL as the page
offset is at 0.
[1] https://lore.kernel.org/lkml/Y7h4jsv6jl0XSIsk@xxxxxxxxxxxxxxxxxxxx/T/
