ipc/util.c: use register_hotmemory_notifier()

Squishes a statement-with-no-effect warning, removes some ifdefs and
shrinks .text by one byte!

Note that this code fails to check for blocking_notifier_chain_register()
failures.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 7 deletions

diff --git a/ipc/util.c b/ipc/util.c
index 464a8abd779f..03eadd8fb0fd 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -23,6 +23,7 @@
 #include <linux/msg.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
+#include <linux/notifier.h>
 #include <linux/capability.h>
 #include <linux/highuid.h>
 #include <linux/security.h>
@@ -47,19 +48,16 @@ struct ipc_proc_iface {
         int (*show)(struct seq_file *, void *);
 };
 
-#ifdef CONFIG_MEMORY_HOTPLUG
-
 static void ipc_memory_notifier(struct work_struct *work)
 {
         ipcns_notify(IPCNS_MEMCHANGED);
 }
 
-static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
-
-
 static int ipc_memory_callback(struct notifier_block *self,
                                 unsigned long action, void *arg)
 {
+        static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
+
         switch (action) {
         case MEM_ONLINE:    /* memory successfully brought online */
         case MEM_OFFLINE:   /* or offline: it's time to recompute msgmni */
@@ -85,7 +83,10 @@ static int ipc_memory_callback(struct notifier_block *self,
         return NOTIFY_OK;
 }
 
-#endif /* CONFIG_MEMORY_HOTPLUG */
+static struct notifier_block ipc_memory_nb = {
+        .notifier_call = ipc_memory_callback,
+        .priority = IPC_CALLBACK_PRI,
+};
 
 /**
  *      ipc_init        -       initialise IPC subsystem
@@ -102,7 +103,7 @@ static int __init ipc_init(void)
         sem_init();
         msg_init();
         shm_init();
-        hotplug_memory_notifier(ipc_memory_callback, IPC_CALLBACK_PRI);
+        register_hotmemory_notifier(&ipc_memory_nb);
         register_ipcns_notifier(&init_ipc_ns);
         return 0;
 }