Commit 0e6d31a7 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds

page-flags: move code around

The preparation patch: we are going to use compound_head(), PageTail()
and PageCompound() to define page-flags helpers.

Let's define them before macros.

We cannot user PageHead() helper in PageCompound() as it's not yet
defined -- use test_bit(PG_head, &page->flags) instead.
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d8c1bdeb
...@@ -133,6 +133,27 @@ enum pageflags { ...@@ -133,6 +133,27 @@ enum pageflags {
#ifndef __GENERATING_BOUNDS_H #ifndef __GENERATING_BOUNDS_H
struct page; /* forward declaration */
static inline struct page *compound_head(struct page *page)
{
unsigned long head = READ_ONCE(page->compound_head);
if (unlikely(head & 1))
return (struct page *) (head - 1);
return page;
}
static inline int PageTail(struct page *page)
{
return READ_ONCE(page->compound_head) & 1;
}
static inline int PageCompound(struct page *page)
{
return test_bit(PG_head, &page->flags) || PageTail(page);
}
/* /*
* Macros to create function definitions for page flags * Macros to create function definitions for page flags
*/ */
...@@ -204,7 +225,6 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; } ...@@ -204,7 +225,6 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
#define TESTSCFLAG_FALSE(uname) \ #define TESTSCFLAG_FALSE(uname) \
TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname)
struct page; /* forward declaration */
TESTPAGEFLAG(Locked, locked) TESTPAGEFLAG(Locked, locked)
PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error) PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
...@@ -395,11 +415,6 @@ static inline void set_page_writeback_keepwrite(struct page *page) ...@@ -395,11 +415,6 @@ static inline void set_page_writeback_keepwrite(struct page *page)
__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head) __PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
static inline int PageTail(struct page *page)
{
return READ_ONCE(page->compound_head) & 1;
}
static inline void set_compound_head(struct page *page, struct page *head) static inline void set_compound_head(struct page *page, struct page *head)
{ {
WRITE_ONCE(page->compound_head, (unsigned long)head + 1); WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
...@@ -410,20 +425,6 @@ static inline void clear_compound_head(struct page *page) ...@@ -410,20 +425,6 @@ static inline void clear_compound_head(struct page *page)
WRITE_ONCE(page->compound_head, 0); WRITE_ONCE(page->compound_head, 0);
} }
static inline struct page *compound_head(struct page *page)
{
unsigned long head = READ_ONCE(page->compound_head);
if (unlikely(head & 1))
return (struct page *) (head - 1);
return page;
}
static inline int PageCompound(struct page *page)
{
return PageHead(page) || PageTail(page);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE #ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline void ClearPageCompound(struct page *page) static inline void ClearPageCompound(struct page *page)
{ {
......
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