thp: compound_lock

Add a new compound_lock() needed to serialize put_page against
__split_huge_page_refcount().

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli 2011-01-13 15:46:32 -08:00 committed by Linus Torvalds
parent a826e42242
commit e9da73d677
2 changed files with 45 additions and 1 deletions

View file

@ -14,6 +14,7 @@
#include <linux/mm_types.h>
#include <linux/range.h>
#include <linux/pfn.h>
#include <linux/bit_spinlock.h>
struct mempolicy;
struct anon_vma;
@ -305,6 +306,39 @@ static inline int is_vmalloc_or_module_addr(const void *x)
}
#endif
static inline void compound_lock(struct page *page)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
bit_spin_lock(PG_compound_lock, &page->flags);
#endif
}
static inline void compound_unlock(struct page *page)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
bit_spin_unlock(PG_compound_lock, &page->flags);
#endif
}
static inline unsigned long compound_lock_irqsave(struct page *page)
{
unsigned long uninitialized_var(flags);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
local_irq_save(flags);
compound_lock(page);
#endif
return flags;
}
static inline void compound_unlock_irqrestore(struct page *page,
unsigned long flags)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
compound_unlock(page);
local_irq_restore(flags);
#endif
}
static inline struct page *compound_head(struct page *page)
{
if (unlikely(PageTail(page)))

View file

@ -107,6 +107,9 @@ enum pageflags {
#endif
#ifdef CONFIG_MEMORY_FAILURE
PG_hwpoison, /* hardware poisoned page. Don't touch */
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
PG_compound_lock,
#endif
__NR_PAGEFLAGS,
@ -397,6 +400,12 @@ static inline void __ClearPageTail(struct page *page)
#define __PG_MLOCKED 0
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define __PG_COMPOUND_LOCK (1 << PG_compound_lock)
#else
#define __PG_COMPOUND_LOCK 0
#endif
/*
* Flags checked when a page is freed. Pages being freed should not have
* these flags set. It they are, there is a problem.
@ -406,7 +415,8 @@ static inline void __ClearPageTail(struct page *page)
1 << PG_private | 1 << PG_private_2 | \
1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON)
1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON | \
__PG_COMPOUND_LOCK)
/*
* Flags checked when a page is prepped for return by the page allocator.