From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
This function returns the order of a transparent huge page. It
compiles to 0 if CONFIG_TRANSPARENT_HUGEPAGE is disabled.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 71f20776b06c..dd19720a8bc2 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -265,6 +265,19 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
else
return NULL;
}
+
+/**
+ * thp_order - Order of a transparent huge page.
+ * @page: Head page of a transparent huge page.
+ */
+static inline unsigned int thp_order(struct page *page)
+{
+ VM_BUG_ON_PGFLAGS(PageTail(page), page);
+ if (PageHead(page))
+ return HPAGE_PMD_ORDER;
+ return 0;
+}
+
static inline int hpage_nr_pages(struct page *page)
{
if (unlikely(PageTransHuge(page)))
@@ -324,6 +337,12 @@ static inline struct list_head *page_deferred_list(struct page *page)
#define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
#define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
+static inline unsigned int thp_order(struct page *page)
+{
+ VM_BUG_ON_PGFLAGS(PageTail(page), page);
+ return 0;
+}
+
static inline int hpage_nr_pages(struct page *page)
{
VM_BUG_ON_PAGE(PageTail(page), page);
--
2.26.2
