diff options
Diffstat (limited to 'ipc/util.c')
| -rw-r--r-- | ipc/util.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/ipc/util.c b/ipc/util.c index c27f0e92f489..2d545d7144a7 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -33,6 +33,7 @@ #include <linux/audit.h> #include <linux/nsproxy.h> #include <linux/rwsem.h> +#include <linux/memory.h> #include <linux/ipc_namespace.h> #include <asm/unistd.h> @@ -55,11 +56,41 @@ struct ipc_namespace init_ipc_ns = { atomic_t nr_ipc_ns = ATOMIC_INIT(1); +#ifdef CONFIG_MEMORY_HOTPLUG + +static int ipc_memory_callback(struct notifier_block *self, + unsigned long action, void *arg) +{ + switch (action) { + case MEM_ONLINE: /* memory successfully brought online */ + case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */ + /* + * This is done by invoking the ipcns notifier chain with the + * IPC_MEMCHANGED event. + */ + ipcns_notify(IPCNS_MEMCHANGED); + break; + case MEM_GOING_ONLINE: + case MEM_GOING_OFFLINE: + case MEM_CANCEL_ONLINE: + case MEM_CANCEL_OFFLINE: + default: + break; + } + + return NOTIFY_OK; +} + +#endif /* CONFIG_MEMORY_HOTPLUG */ + /** * ipc_init - initialise IPC subsystem * * The various system5 IPC resources (semaphores, messages and shared * memory) are initialised + * A callback routine is registered into the memory hotplug notifier + * chain: since msgmni scales to lowmem this callback routine will be + * called upon successful memory add / remove to recompute msmgni. */ static int __init ipc_init(void) @@ -67,6 +98,8 @@ static int __init ipc_init(void) sem_init(); msg_init(); shm_init(); + hotplug_memory_notifier(ipc_memory_callback, IPC_CALLBACK_PRI); + register_ipcns_notifier(&init_ipc_ns); return 0; } __initcall(ipc_init); |