This change is in preparation for the conversion of
queue_pages_required() to queue_folio_required() and migrate_page_add()
to migrate_folio_add().
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
---
mm/mempolicy.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ae9d16124f45..ea8cac447e04 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -558,7 +558,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
return addr != end ? -EIO : 0;
}
-static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
+static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
@@ -566,7 +566,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
#ifdef CONFIG_HUGETLB_PAGE
struct queue_pages *qp = walk->private;
unsigned long flags = (qp->flags & MPOL_MF_VALID);
- struct page *page;
+ struct folio *folio;
spinlock_t *ptl;
pte_t entry;
@@ -574,13 +574,13 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
entry = huge_ptep_get(pte);
if (!pte_present(entry))
goto unlock;
- page = pte_page(entry);
- if (!queue_pages_required(page, qp))
+ folio = pfn_folio(pte_pfn(entry));
+ if (!queue_pages_required(&folio->page, qp))
goto unlock;
if (flags == MPOL_MF_STRICT) {
/*
- * STRICT alone means only detecting misplaced page and no
+ * STRICT alone means only detecting misplaced folio and no
* need to further check other vma.
*/
ret = -EIO;
@@ -591,20 +591,27 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
/*
* Must be STRICT with MOVE*, otherwise .test_walk() have
* stopped walking current vma.
- * Detecting misplaced page but allow migrating pages which
+ * Detecting misplaced folio but allow migrating folios which
* have been queued.
*/
ret = 1;
goto unlock;
}
- /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
+ /*
+ * With MPOL_MF_MOVE, we try to migrate only unshared folios. If it
+ * is shared it is likely not worth migrating.
+ *
+ * To check if the folio is shared, ideally we want to make sure
+ * every page is mapped to the same process. Doing that is very
+ * expensive, so check the estimated mapcount of the folio instead.
+ */
if (flags & (MPOL_MF_MOVE_ALL) ||
- (flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) {
- if (isolate_hugetlb(page_folio(page), qp->pagelist) &&
+ (flags & MPOL_MF_MOVE && folio_estimated_mapcount(folio) == 1)) {
+ if (isolate_hugetlb(folio, qp->pagelist) &&
(flags & MPOL_MF_STRICT))
/*
- * Failed to isolate page but allow migrating pages
+ * Failed to isolate folio but allow migrating folios
* which have been queued.
*/
ret = 1;
@@ -702,7 +709,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
}
static const struct mm_walk_ops queue_pages_walk_ops = {
- .hugetlb_entry = queue_pages_hugetlb,
+ .hugetlb_entry = queue_folios_hugetlb,
.pmd_entry = queue_folios_pte_range,
.test_walk = queue_pages_test_walk,
};
--
2.38.1
