[PATCH v5 2/5] drm/pagemap: Unlock and put folios when possible

Francois Dugast
2026-01-14T19:21:54Z

If the page is part of a folio, unlock and put the whole folio at once
instead of individual pages one after the other. This will reduce the
amount of operations once device THP are in use.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: linux-mm@kvack.org
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
---
drivers/gpu/drm/drm_pagemap.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index c497726b0147..b31090b8e97c 100644
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -154,15 +154,15 @@ static void drm_pagemap_zdd_put(struct drm_pagemap_zdd *zdd)
}

/**
- * drm_pagemap_migration_unlock_put_page() - Put a migration page
- * @page: Pointer to the page to put
+ * drm_pagemap_migration_unlock_put_folio() - Put a migration folio
+ * @folio: Pointer to the folio to put
*
- * This function unlocks and puts a page.
+ * This function unlocks and puts a folio.
*/
-static void drm_pagemap_migration_unlock_put_page(struct page *page)
+static void drm_pagemap_migration_unlock_put_folio(struct folio *folio)
{
- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
}

/**
@@ -177,15 +177,23 @@ static void drm_pagemap_migration_unlock_put_pages(unsigned long npages,
{
unsigned long i;

- for (i = 0; i < npages; ++i) {
+ for (i = 0; i < npages;) {
struct page *page;
+ struct folio *folio;
+ unsigned int order = 0;

if (!migrate_pfn[i])
- continue;
+ goto next;

page = migrate_pfn_to_page(migrate_pfn[i]);
- drm_pagemap_migration_unlock_put_page(page);
+ folio = page_folio(page);
+ order = folio_order(folio);
+
+ drm_pagemap_migration_unlock_put_folio(folio);
migrate_pfn[i] = 0;
+
+next:
+ i += NR_PAGES(order);
}
}

--
2.43.0