[v2,06/25] mm: Allow hpages to be arbitrary order
diff mbox series

Message ID 20200212041845.25879-7-willy@infradead.org
State New
Headers show
Series
  • Large pages in the page cache
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Commit Message

Matthew Wilcox Feb. 12, 2020, 4:18 a.m. UTC
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Remove the assumption in hpage_nr_pages() that compound pages are
necessarily PMD sized.  The return type needs to be signed as we need
to use the negative value, eg when calling update_lru_size().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/huge_mm.h | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

Comments

Kirill A. Shutemov Feb. 13, 2020, 2:11 p.m. UTC | #1
On Tue, Feb 11, 2020 at 08:18:26PM -0800, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> Remove the assumption in hpage_nr_pages() that compound pages are
> necessarily PMD sized.  The return type needs to be signed as we need
> to use the negative value, eg when calling update_lru_size().

But should it be long?
Any reason to use macros instead of inline function?
Matthew Wilcox Feb. 13, 2020, 2:30 p.m. UTC | #2
On Thu, Feb 13, 2020 at 05:11:07PM +0300, Kirill A. Shutemov wrote:
> On Tue, Feb 11, 2020 at 08:18:26PM -0800, Matthew Wilcox wrote:
> > From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> > 
> > Remove the assumption in hpage_nr_pages() that compound pages are
> > necessarily PMD sized.  The return type needs to be signed as we need
> > to use the negative value, eg when calling update_lru_size().
> 
> But should it be long?
> Any reason to use macros instead of inline function?

Huh, that does look like a bit of a weird change now you point it out.
I'll change it back:

 static inline int hpage_nr_pages(struct page *page)
 {
-	if (unlikely(PageTransHuge(page)))
-		return HPAGE_PMD_NR;
-	return 1;
+	return compound_nr(page);
 }

Patch
diff mbox series

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 5aca3d1bdb32..16367e2f771e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -230,12 +230,8 @@  static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 	else
 		return NULL;
 }
-static inline int hpage_nr_pages(struct page *page)
-{
-	if (unlikely(PageTransHuge(page)))
-		return HPAGE_PMD_NR;
-	return 1;
-}
+
+#define hpage_nr_pages(page)	(long)compound_nr(page)
 
 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 		pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
@@ -289,7 +285,7 @@  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
+#define hpage_nr_pages(x) 1L
 
 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 {