GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-21 06:12:56 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

mm: move anon_vma ref out from under CONFIG_foo

Browse source 
We need the anon_vma refcount unconditionally to simplify the anon_vma
lifetime rules.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.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:
Peter Zijlstra 2011-03-22 16:32:48 -07:00 • committed by Linus Torvalds
parent 9e60109f12
commit 83813267c6
2 changed files with 10 additions and 44 deletions
Download patch file Download diff file Expand all files Collapse all files

40
include/linux/rmap.h
View file

@ -27,18 +27,15 @@
struct anon_vma {
struct anon_vma *root; /* Root of this anon_vma tree */
spinlock_t lock; /* Serialize access to vma list */
#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION)
/*
* The external_refcount is taken by either KSM or page migration
* to take a reference to an anon_vma when there is no
* The refcount is taken on an anon_vma when there is no
* guarantee that the vma of page tables will exist for
* the duration of the operation. A caller that takes
* the reference is responsible for clearing up the
* anon_vma if they are the last user on release
*/
atomic_t external_refcount;
#endif
atomic_t refcount;
/*
* NOTE: the LSB of the head.next is set by
* mm_take_all_locks() _after_ taking the above lock. So the
@ -71,41 +68,12 @@ struct anon_vma_chain {
};
#ifdef CONFIG_MMU
#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION)
static inline void anonvma_external_refcount_init(struct anon_vma *anon_vma)
{
atomic_set(&anon_vma->external_refcount, 0);
}
static inline int anonvma_external_refcount(struct anon_vma *anon_vma)
{
return atomic_read(&anon_vma->external_refcount);
}
static inline void get_anon_vma(struct anon_vma *anon_vma)
{
atomic_inc(&anon_vma->external_refcount);
atomic_inc(&anon_vma->refcount);
}
void put_anon_vma(struct anon_vma *);
#else
static inline void anonvma_external_refcount_init(struct anon_vma *anon_vma)
{
}
static inline int anonvma_external_refcount(struct anon_vma *anon_vma)
{
return 0;
}
static inline void get_anon_vma(struct anon_vma *anon_vma)
{
}
static inline void put_anon_vma(struct anon_vma *anon_vma)
{
}
#endif /* CONFIG_KSM */
static inline struct anon_vma *page_anon_vma(struct page *page)
{