percpu: make percpu symbols under kernel/ and mm/ unique

This patch updates percpu related symbols under kernel/ and mm/ such
that percpu symbols are unique and don't clash with local symbols.
This serves two purposes of decreasing the possibility of global
percpu symbol collision and allowing dropping per_cpu__ prefix from
percpu symbols.

* kernel/lockdep.c: s/lock_stats/cpu_lock_stats/

* kernel/sched.c: s/init_rq_rt/init_rt_rq_var/	(any better idea?)
  		  s/sched_group_cpus/sched_groups/

* kernel/softirq.c: s/ksoftirqd/run_ksoftirqd/a

* kernel/softlockup.c: s/(*)_timestamp/softlockup_\1_ts/
  		       s/watchdog_task/softlockup_watchdog/
		       s/timestamp/ts/ for local variables

* kernel/time/timer_stats: s/lookup_lock/tstats_lookup_lock/

* mm/slab.c: s/reap_work/slab_reap_work/
  	     s/reap_node/slab_reap_node/

* mm/vmstat.c: local variable changed to avoid collision with vmstat_work

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: (slab/vmstat) Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>

2 files changed, 12 insertions, 13 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 7dfa481c96ba..211b1746c63c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -685,7 +685,7 @@ int slab_is_available(void)
         return g_cpucache_up >= EARLY;
 }
 
-static DEFINE_PER_CPU(struct delayed_work, reap_work);
+static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
 
 static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
 {
@@ -826,7 +826,7 @@ __setup("noaliencache", noaliencache_setup);
  * objects freed on different nodes from which they were allocated) and the
  * flushing of remote pcps by calling drain_node_pages.
  */
-static DEFINE_PER_CPU(unsigned long, reap_node);
+static DEFINE_PER_CPU(unsigned long, slab_reap_node);
 
 static void init_reap_node(int cpu)
 {
@@ -836,17 +836,17 @@ static void init_reap_node(int cpu)
         if (node == MAX_NUMNODES)
                 node = first_node(node_online_map);
 
-        per_cpu(reap_node, cpu) = node;
+        per_cpu(slab_reap_node, cpu) = node;
 }
 
 static void next_reap_node(void)
 {
-        int node = __get_cpu_var(reap_node);
+        int node = __get_cpu_var(slab_reap_node);
 
         node = next_node(node, node_online_map);
         if (unlikely(node >= MAX_NUMNODES))
                 node = first_node(node_online_map);
-        __get_cpu_var(reap_node) = node;
+        __get_cpu_var(slab_reap_node) = node;
 }
 
 #else
@@ -863,7 +863,7 @@ static void next_reap_node(void)
  */
 static void __cpuinit start_cpu_timer(int cpu)
 {
-        struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
+        struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
 
         /*
          * When this gets called from do_initcalls via cpucache_init(),
@@ -1027,7 +1027,7 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
  */
 static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
 {
-        int node = __get_cpu_var(reap_node);
+        int node = __get_cpu_var(slab_reap_node);
 
         if (l3->alien) {
                 struct array_cache *ac = l3->alien[node];
@@ -1286,9 +1286,9 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
                  * anything expensive but will only modify reap_work
                  * and reschedule the timer.
                 */
-                cancel_rearming_delayed_work(&per_cpu(reap_work, cpu));
+                cancel_rearming_delayed_work(&per_cpu(slab_reap_work, cpu));
                 /* Now the cache_reaper is guaranteed to be not running. */
-                per_cpu(reap_work, cpu).work.func = NULL;
+                per_cpu(slab_reap_work, cpu).work.func = NULL;
                 break;
         case CPU_DOWN_FAILED:
         case CPU_DOWN_FAILED_FROZEN:
diff --git a/mm/vmstat.c b/mm/vmstat.c
index c81321f9feec..dad2327e4580 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -883,11 +883,10 @@ static void vmstat_update(struct work_struct *w)
 
 static void __cpuinit start_cpu_timer(int cpu)
 {
-        struct delayed_work *vmstat_work = &per_cpu(vmstat_work, cpu);
+        struct delayed_work *work = &per_cpu(vmstat_work, cpu);
 
-        INIT_DELAYED_WORK_DEFERRABLE(vmstat_work, vmstat_update);
-        schedule_delayed_work_on(cpu, vmstat_work,
-                                 __round_jiffies_relative(HZ, cpu));
+        INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
+        schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
 }
 
 /*