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linux-next/include/linux/page_idle.h
Yang Shi f86e427197 mm: check the return value of lookup_page_ext for all call sites
Per the discussion with Joonsoo Kim [1], we need check the return value
of lookup_page_ext() for all call sites since it might return NULL in
some cases, although it is unlikely, i.e.  memory hotplug.

Tested with ltp with "page_owner=0".

[1] http://lkml.kernel.org/r/20160519002809.GA10245@js1304-P5Q-DELUXE

[akpm@linux-foundation.org: fix build-breaking typos]
[arnd@arndb.de: fix build problems from lookup_page_ext]
  Link: http://lkml.kernel.org/r/6285269.2CksypHdYp@wuerfel
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1464023768-31025-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03 15:06:22 -07:00

140 lines
2.6 KiB
C

#ifndef _LINUX_MM_PAGE_IDLE_H
#define _LINUX_MM_PAGE_IDLE_H
#include <linux/bitops.h>
#include <linux/page-flags.h>
#include <linux/page_ext.h>
#ifdef CONFIG_IDLE_PAGE_TRACKING
#ifdef CONFIG_64BIT
static inline bool page_is_young(struct page *page)
{
return PageYoung(page);
}
static inline void set_page_young(struct page *page)
{
SetPageYoung(page);
}
static inline bool test_and_clear_page_young(struct page *page)
{
return TestClearPageYoung(page);
}
static inline bool page_is_idle(struct page *page)
{
return PageIdle(page);
}
static inline void set_page_idle(struct page *page)
{
SetPageIdle(page);
}
static inline void clear_page_idle(struct page *page)
{
ClearPageIdle(page);
}
#else /* !CONFIG_64BIT */
/*
* If there is not enough space to store Idle and Young bits in page flags, use
* page ext flags instead.
*/
extern struct page_ext_operations page_idle_ops;
static inline bool page_is_young(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return false;
return test_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline void set_page_young(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return;
set_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline bool test_and_clear_page_young(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return false;
return test_and_clear_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline bool page_is_idle(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return false;
return test_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
static inline void set_page_idle(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return;
set_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
static inline void clear_page_idle(struct page *page)
{
struct page_ext *page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return;
clear_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
#endif /* CONFIG_64BIT */
#else /* !CONFIG_IDLE_PAGE_TRACKING */
static inline bool page_is_young(struct page *page)
{
return false;
}
static inline void set_page_young(struct page *page)
{
}
static inline bool test_and_clear_page_young(struct page *page)
{
return false;
}
static inline bool page_is_idle(struct page *page)
{
return false;
}
static inline void set_page_idle(struct page *page)
{
}
static inline void clear_page_idle(struct page *page)
{
}
#endif /* CONFIG_IDLE_PAGE_TRACKING */
#endif /* _LINUX_MM_PAGE_IDLE_H */