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authorNadia Derbey <Nadia.Derbey@bull.net>2007-10-18 23:40:50 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:44 -0700
commit637c36634029e4e7c81112796dafc32d56355b4a (patch)
treeb30106d838864fe6c8ba97c7dc68304b820e7694 /ipc/shm.c
parent7748dbfaa010b12d5fb9ddf80199534c565c6bce (diff)
downloadlinux-linaro-stable-637c36634029e4e7c81112796dafc32d56355b4a.tar.gz
ipc: remove the ipc_get() routine
This is a trivial patch that removes the ipc_get() routine: it is replaced by a call to idr_find(). Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/shm.c')
-rw-r--r--ipc/shm.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index d20cc25c5bdf..8cf1cf3d5bec 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -63,8 +63,6 @@ static struct ipc_ids init_shm_ids;
((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
#define shm_unlock(shp) \
ipc_unlock(&(shp)->shm_perm)
-#define shm_get(ns, id) \
- ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
#define shm_buildid(ns, id, seq) \
ipc_buildid(&shm_ids(ns), id, seq)
@@ -563,7 +561,19 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
struct shmid_kernel *shp;
struct inode *inode;
- shp = shm_get(ns, next_id);
+ /*
+ * idr_find() is called via shm_get(), so with shm_ids.mutex
+ * locked. Since ipc_addid() is also called with
+ * shm_ids.mutex down, there is no need to add read barriers
+ * here to gurantee the writes in ipc_addid() are seen in
+ * order here (for Alpha).
+ * However idr_find() itself does not necessary require
+ * ipc_ids.mutex down. So if idr_find() is used by other
+ * places without ipc_ids.mutex down, then it needs read
+ * read memory barriers as ipc_lock() does.
+ */
+
+ shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
if (shp == NULL)
continue;