From 6ffbb45826f5d9ae09aa60cd88594b7816c96190 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Fri, 14 Aug 2020 17:30:30 -0700
Subject: [PATCH] mm: add thp_order
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@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-4-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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 467302056e171..9521cfdf18ca1 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -258,6 +258,19 @@ 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)))
@@ -317,6 +330,12 @@ 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);
--
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