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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-03-22 16:32:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-22 17:44:03 -0700 |
| commit | 83813267c699ab11cc65a6d9d0f42db42f0862b3 (patch) | |
| tree | 8a3257ae177ba0f1bb0aebd4a503357c26472908 /mm/rmap.c | |
| parent | 9e60109f125013b6c571f399a15a8b0fe1ffa4e6 (diff) | |
| download | lwn-83813267c699ab11cc65a6d9d0f42db42f0862b3.tar.gz lwn-83813267c699ab11cc65a6d9d0f42db42f0862b3.zip | |
mm: move anon_vma ref out from under CONFIG_foo
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>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index ad416afb2061..873cd9ef912c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -272,7 +272,7 @@ static void anon_vma_unlink(struct anon_vma_chain *anon_vma_chain) list_del(&anon_vma_chain->same_anon_vma); /* We must garbage collect the anon_vma if it's empty */ - empty = list_empty(&anon_vma->head) && !anonvma_external_refcount(anon_vma); + empty = list_empty(&anon_vma->head) && !atomic_read(&anon_vma->refcount); anon_vma_unlock(anon_vma); if (empty) { @@ -303,7 +303,7 @@ static void anon_vma_ctor(void *data) struct anon_vma *anon_vma = data; spin_lock_init(&anon_vma->lock); - anonvma_external_refcount_init(anon_vma); + atomic_set(&anon_vma->refcount, 0); INIT_LIST_HEAD(&anon_vma->head); } @@ -1486,7 +1486,6 @@ int try_to_munlock(struct page *page) return try_to_unmap_file(page, TTU_MUNLOCK); } -#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION) /* * Drop an anon_vma refcount, freeing the anon_vma and anon_vma->root * if necessary. Be careful to do all the tests under the lock. Once @@ -1495,8 +1494,8 @@ int try_to_munlock(struct page *page) */ void put_anon_vma(struct anon_vma *anon_vma) { - BUG_ON(atomic_read(&anon_vma->external_refcount) <= 0); - if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->root->lock)) { + BUG_ON(atomic_read(&anon_vma->refcount) <= 0); + if (atomic_dec_and_lock(&anon_vma->refcount, &anon_vma->root->lock)) { struct anon_vma *root = anon_vma->root; int empty = list_empty(&anon_vma->head); int last_root_user = 0; @@ -1507,8 +1506,8 @@ void put_anon_vma(struct anon_vma *anon_vma) * the refcount on the root and check if we need to free it. */ if (empty && anon_vma != root) { - BUG_ON(atomic_read(&root->external_refcount) <= 0); - last_root_user = atomic_dec_and_test(&root->external_refcount); + BUG_ON(atomic_read(&root->refcount) <= 0); + last_root_user = atomic_dec_and_test(&root->refcount); root_empty = list_empty(&root->head); } anon_vma_unlock(anon_vma); @@ -1520,7 +1519,6 @@ void put_anon_vma(struct anon_vma *anon_vma) } } } -#endif #ifdef CONFIG_MIGRATION /* |