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>
diff --git a/ipc/shm.c b/ipc/shm.c
index 07f4b7a..fe92471 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -56,9 +56,7 @@
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) \
ipc_unlock(&(shp)->shm_perm)
@@ -72,14 +70,13 @@
static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
#endif
-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 @@
}
#ifdef CONFIG_IPC_NS
-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 @@
total++;
}
up_write(&shm_ids(ns).rw_mutex);
-
- kfree(ns->ids[IPC_SHM_IDS]);
- ns->ids[IPC_SHM_IDS] = NULL;
}
#endif
void __init shm_init (void)
{
- __shm_init_ns(&init_ipc_ns, &init_shm_ids);
+ shm_init_ns(&init_ipc_ns);
ipc_init_proc_interface("sysvipc/shm",
" key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
IPC_SHM_IDS, sysvipc_shm_proc_show);