From ed2ddbf88c0ddeeae4c78bb306a116dfd867c55c Mon Sep 17 00:00:00 2001 From: Pierre Peiffer Date: Fri, 8 Feb 2008 04:18:57 -0800 Subject: 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 Acked-by: Cedric Le Goater Cc: Pavel Emelyanov Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/shm.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) (limited to 'ipc/shm.c') 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) \ ipc_unlock(&(shp)->shm_perm) @@ -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); #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 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) } #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 @@ void shm_exit_ns(struct ipc_namespace *ns) 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); -- cgit v1.2.3