Add a helper function to allow device drivers to create device private transparent huge pages. This is intended to help support device private THP migrations.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- include/linux/huge_mm.h | 5 +++++ mm/huge_memory.c | 8 ++++++++ 2 files changed, 13 insertions(+)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 87b42c81dedc..126e54da4fee 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -187,6 +187,7 @@ extern unsigned long thp_get_unmapped_area(struct file *filp, unsigned long flags);
extern void prep_transhuge_page(struct page *page); +extern void prep_transhuge_device_private_page(struct page *page); extern void free_transhuge_page(struct page *page); bool is_transparent_hugepage(struct page *page);
@@ -382,6 +383,10 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
static inline void prep_transhuge_page(struct page *page) {}
+static inline void prep_transhuge_device_private_page(struct page *page) +{ +} + static inline bool is_transparent_hugepage(struct page *page) { return false; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index a8d48994481a..1e848cc0c3dc 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -498,6 +498,14 @@ void prep_transhuge_page(struct page *page) set_compound_page_dtor(page, TRANSHUGE_PAGE_DTOR); }
+void prep_transhuge_device_private_page(struct page *page) +{ + prep_compound_page(page, HPAGE_PMD_ORDER); + prep_transhuge_page(page); + percpu_ref_put_many(page->pgmap->ref, HPAGE_PMD_NR - 1); +} +EXPORT_SYMBOL_GPL(prep_transhuge_device_private_page); + bool is_transparent_hugepage(struct page *page) { if (!PageCompound(page))