[PATCH] hotplug CPU: clean up hotcpu_notifier() use

There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.

the compiler can skip truly unused functions just fine:

    text    data     bss     dec     hex filename
 1624412  728710 3674856 6027978  5bfaca vmlinux.before
 1624412  728710 3674856 6027978  5bfaca vmlinux.after

[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 1 insertions, 11 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index bd1e89c4c96a..9b62b4c03ad0 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2044,7 +2044,6 @@ out:
         return err;
 }
 
-#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG)
 /*
  * If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs
  * or memory nodes, we need to walk over the cpuset hierarchy,
@@ -2108,9 +2107,7 @@ static void common_cpu_mem_hotplug_unplug(void)
         mutex_unlock(&callback_mutex);
         mutex_unlock(&manage_mutex);
 }
-#endif
 
-#ifdef CONFIG_HOTPLUG_CPU
 /*
  * The top_cpuset tracks what CPUs and Memory Nodes are online,
  * period.  This is necessary in order to make cpusets transparent
@@ -2127,7 +2124,6 @@ static int cpuset_handle_cpuhp(struct notifier_block *nb,
         common_cpu_mem_hotplug_unplug();
         return 0;
 }
-#endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
diff --git a/kernel/profile.c b/kernel/profile.c
index 04fd84e8cdbe..0961d93e1d91 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -319,7 +319,6 @@ out:
         put_cpu();
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 static int __devinit profile_cpu_callback(struct notifier_block *info,
                                         unsigned long action, void *__cpu)
 {
@@ -372,10 +371,10 @@ static int __devinit profile_cpu_callback(struct notifier_block *info,
         }
         return NOTIFY_OK;
 }
-#endif /* CONFIG_HOTPLUG_CPU */
 #else /* !CONFIG_SMP */
 #define profile_flip_buffers()          do { } while (0)
 #define profile_discard_flip_buffers()  do { } while (0)
+#define profile_cpu_callback            NULL
 
 void profile_hits(int type, void *__pc, unsigned int nr_hits)
 {
diff --git a/kernel/sched.c b/kernel/sched.c
index 75a005ed4eda..c83f531c2886 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6740,8 +6740,6 @@ SYSDEV_ATTR(sched_smt_power_savings, 0644, sched_smt_power_savings_show,
             sched_smt_power_savings_store);
 #endif
 
-
-#ifdef CONFIG_HOTPLUG_CPU
 /*
  * Force a reinitialization of the sched domains hierarchy.  The domains
  * and groups cannot be updated in place without racing with the balancing
@@ -6774,7 +6772,6 @@ static int update_sched_domains(struct notifier_block *nfb,
 
         return NOTIFY_OK;
 }
-#endif
 
 void __init sched_init_smp(void)
 {
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5484d6e045c2..c5257316f4b9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -655,7 +655,6 @@ int current_is_keventd(void)
 
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 /* Take the work from this (downed) CPU. */
 static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
 {
@@ -738,7 +737,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 
         return NOTIFY_OK;
 }
-#endif
 
 void init_workqueues(void)
 {