diff mbox series

[v2,3/8] mm: Check PageTail in hpage_nr_pages even when !THP

Message ID 20200318140253.6141-4-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Misc MM patches | expand

Commit Message

Matthew Wilcox March 18, 2020, 2:02 p.m. UTC 
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

It's even more important to check that we don't have a tail page when
calling hpage_nr_pages() when THP are disabled.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/huge_mm.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig March 19, 2020, 10:18 a.m. UTC | #1 
On Wed, Mar 18, 2020 at 07:02:48AM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> It's even more important to check that we don't have a tail page when
> calling hpage_nr_pages() when THP are disabled.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Kirill A. Shutemov March 19, 2020, 2:33 p.m. UTC | #2 
On Wed, Mar 18, 2020 at 07:02:48AM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> It's even more important to check that we don't have a tail page when
> calling hpage_nr_pages() when THP are disabled.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
diff mbox series

Patch

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 5aca3d1bdb32..a155a7929b34 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -289,7 +289,11 @@  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; })
 
-#define hpage_nr_pages(x) 1
+static inline int hpage_nr_pages(struct page *page)
+{
+	VM_BUG_ON_PAGE(PageTail(page), page);
+	return 1;
+}
 
 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 {