path: root/ipc/shm.c
diff options
authorPierre Peiffer <pierre.peiffer@bull.net>2008-02-08 04:18:57 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-08 09:22:26 -0800
commited2ddbf88c0ddeeae4c78bb306a116dfd867c55c (patch)
treede6d6828c03f98be6fc41e8acf3b3e52df28be9b /ipc/shm.c
parent4b9fcb0ec60584d639ad105c42b75a3447071e47 (diff)
IPC: make struct ipc_ids static in ipc_namespace
Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids' are dynamically allocated for each icp_namespace as the ipc_namespace itself (for the init namespace, they are initialized with pointers to static variables instead) It is so for historical reason: in fact, before the use of idr to store the ipcs, the ipcs were stored in tables of variable length, depending of the maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any cases for each new ipc_namespace, there is no gain of memory in having them allocated separately of the struct ipc_namespace. This patch proposes to make this table static in the struct ipc_namespace. Thus, we can allocate all in once and get rid of all the code needed to allocate and free these ipc_ids separately. Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: 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')
1 files changed, 4 insertions, 22 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 07f4b7abc80a..fe92471e19c7 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -56,9 +56,7 @@ struct shm_file_data {
static const struct file_operations shm_file_operations;
static struct vm_operations_struct shm_vm_ops;
-static struct ipc_ids init_shm_ids;
-#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
+#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
#define shm_unlock(shp) \
@@ -72,14 +70,13 @@ static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
-static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void shm_init_ns(struct ipc_namespace *ns)
- ns->ids[IPC_SHM_IDS] = ids;
ns->shm_ctlmax = SHMMAX;
ns->shm_ctlall = SHMALL;
ns->shm_ctlmni = SHMMNI;
ns->shm_tot = 0;
- ipc_init_ids(ids);
+ ipc_init_ids(&ns->ids[IPC_SHM_IDS]);
@@ -98,18 +95,6 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
-int shm_init_ns(struct ipc_namespace *ns)
- struct ipc_ids *ids;
- ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
- if (ids == NULL)
- return -ENOMEM;
- __shm_init_ns(ns, ids);
- return 0;
void shm_exit_ns(struct ipc_namespace *ns)
struct shmid_kernel *shp;
@@ -131,15 +116,12 @@ void shm_exit_ns(struct ipc_namespace *ns)
- kfree(ns->ids[IPC_SHM_IDS]);
- ns->ids[IPC_SHM_IDS] = NULL;
void __init shm_init (void)
- __shm_init_ns(&init_ipc_ns, &init_shm_ids);
+ shm_init_ns(&init_ipc_ns);
" key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
IPC_SHM_IDS, sysvipc_shm_proc_show);