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>

7 files changed, 57 insertions, 56 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 3815ac1d58b..8631320a50d 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -140,7 +140,8 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 }
 
 #ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
+                      cpu_lock_stats);
 
 static int lock_point(unsigned long points[], unsigned long ip)
 {
@@ -186,7 +187,7 @@ struct lock_class_stats lock_stats(struct lock_class *class)
         memset(&stats, 0, sizeof(struct lock_class_stats));
         for_each_possible_cpu(cpu) {
                 struct lock_class_stats *pcs =
-                        &per_cpu(lock_stats, cpu)[class - lock_classes];
+                        &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
 
                 for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
                         stats.contention_point[i] += pcs->contention_point[i];
@@ -213,7 +214,7 @@ void clear_lock_stats(struct lock_class *class)
 
         for_each_possible_cpu(cpu) {
                 struct lock_class_stats *cpu_stats =
-                        &per_cpu(lock_stats, cpu)[class - lock_classes];
+                        &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
 
                 memset(cpu_stats, 0, sizeof(struct lock_class_stats));
         }
@@ -223,12 +224,12 @@ void clear_lock_stats(struct lock_class *class)
 
 static struct lock_class_stats *get_lock_stats(struct lock_class *class)
 {
-        return &get_cpu_var(lock_stats)[class - lock_classes];
+        return &get_cpu_var(cpu_lock_stats)[class - lock_classes];
 }
 
 static void put_lock_stats(struct lock_class_stats *stats)
 {
-        put_cpu_var(lock_stats);
+        put_cpu_var(cpu_lock_stats);
 }
 
 static void lock_release_holdtime(struct held_lock *hlock)
diff --git a/kernel/sched.c b/kernel/sched.c
index 1535f3884b8..854ab418fd4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -298,7 +298,7 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct cfs_rq, init_tg_cfs_rq);
 
 #ifdef CONFIG_RT_GROUP_SCHED
 static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq_var);
 #endif /* CONFIG_RT_GROUP_SCHED */
 #else /* !CONFIG_USER_SCHED */
 #define root_task_group init_task_group
@@ -8199,14 +8199,14 @@ enum s_alloc {
  */
 #ifdef CONFIG_SCHED_SMT
 static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
-static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
+static DEFINE_PER_CPU(struct static_sched_group, sched_groups);
 
 static int
 cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
                  struct sched_group **sg, struct cpumask *unused)
 {
         if (sg)
-                *sg = &per_cpu(sched_group_cpus, cpu).sg;
+                *sg = &per_cpu(sched_groups, cpu).sg;
         return cpu;
 }
 #endif /* CONFIG_SCHED_SMT */
@@ -9470,7 +9470,7 @@ void __init sched_init(void)
 #elif defined CONFIG_USER_SCHED
                 init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL);
                 init_tg_rt_entry(&init_task_group,
-                                &per_cpu(init_rt_rq, i),
+                                &per_cpu(init_rt_rq_var, i),
                                 &per_cpu(init_sched_rt_entity, i), i, 1,
                                 root_task_group.rt_se[i]);
 #endif
diff --git a/kernel/softirq.c b/kernel/softirq.c
index f8749e5216e..0740dfd55c5 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -697,7 +697,7 @@ void __init softirq_init(void)
         open_softirq(HI_SOFTIRQ, tasklet_hi_action);
 }
 
-static int ksoftirqd(void * __bind_cpu)
+static int run_ksoftirqd(void * __bind_cpu)
 {
         set_current_state(TASK_INTERRUPTIBLE);
 
@@ -810,7 +810,7 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb,
         switch (action) {
         case CPU_UP_PREPARE:
         case CPU_UP_PREPARE_FROZEN:
-                p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
+                p = kthread_create(run_ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
                 if (IS_ERR(p)) {
                         printk("ksoftirqd for %i failed\n", hotcpu);
                         return NOTIFY_BAD;
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 81324d12eb3..d22579087e2 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -22,9 +22,9 @@
 
 static DEFINE_SPINLOCK(print_lock);
 
-static DEFINE_PER_CPU(unsigned long, touch_timestamp);
-static DEFINE_PER_CPU(unsigned long, print_timestamp);
-static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
+static DEFINE_PER_CPU(unsigned long, softlockup_touch_ts); /* touch timestamp */
+static DEFINE_PER_CPU(unsigned long, softlockup_print_ts); /* print timestamp */
+static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
 
 static int __read_mostly did_panic;
 int __read_mostly softlockup_thresh = 60;
@@ -70,12 +70,12 @@ static void __touch_softlockup_watchdog(void)
 {
         int this_cpu = raw_smp_processor_id();
 
-        __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu);
+        __raw_get_cpu_var(softlockup_touch_ts) = get_timestamp(this_cpu);
 }
 
 void touch_softlockup_watchdog(void)
 {
-        __raw_get_cpu_var(touch_timestamp) = 0;
+        __raw_get_cpu_var(softlockup_touch_ts) = 0;
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -85,7 +85,7 @@ void touch_all_softlockup_watchdogs(void)
 
         /* Cause each CPU to re-update its timestamp rather than complain */
         for_each_online_cpu(cpu)
-                per_cpu(touch_timestamp, cpu) = 0;
+                per_cpu(softlockup_touch_ts, cpu) = 0;
 }
 EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
 
@@ -104,28 +104,28 @@ int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
 void softlockup_tick(void)
 {
         int this_cpu = smp_processor_id();
-        unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu);
-        unsigned long print_timestamp;
+        unsigned long touch_ts = per_cpu(softlockup_touch_ts, this_cpu);
+        unsigned long print_ts;
         struct pt_regs *regs = get_irq_regs();
         unsigned long now;
 
         /* Is detection switched off? */
-        if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) {
+        if (!per_cpu(softlockup_watchdog, this_cpu) || softlockup_thresh <= 0) {
                 /* Be sure we don't false trigger if switched back on */
-                if (touch_timestamp)
-                        per_cpu(touch_timestamp, this_cpu) = 0;
+                if (touch_ts)
+                        per_cpu(softlockup_touch_ts, this_cpu) = 0;
                 return;
         }
 
-        if (touch_timestamp == 0) {
+        if (touch_ts == 0) {
                 __touch_softlockup_watchdog();
                 return;
         }
 
-        print_timestamp = per_cpu(print_timestamp, this_cpu);
+        print_ts = per_cpu(softlockup_print_ts, this_cpu);
 
         /* report at most once a second */
-        if (print_timestamp == touch_timestamp || did_panic)
+        if (print_ts == touch_ts || did_panic)
                 return;
 
         /* do not print during early bootup: */
@@ -140,18 +140,18 @@ void softlockup_tick(void)
          * Wake up the high-prio watchdog task twice per
          * threshold timespan.
          */
-        if (now > touch_timestamp + softlockup_thresh/2)
-                wake_up_process(per_cpu(watchdog_task, this_cpu));
+        if (now > touch_ts + softlockup_thresh/2)
+                wake_up_process(per_cpu(softlockup_watchdog, this_cpu));
 
         /* Warn about unreasonable delays: */
-        if (now <= (touch_timestamp + softlockup_thresh))
+        if (now <= (touch_ts + softlockup_thresh))
                 return;
 
-        per_cpu(print_timestamp, this_cpu) = touch_timestamp;
+        per_cpu(softlockup_print_ts, this_cpu) = touch_ts;
 
         spin_lock(&print_lock);
         printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n",
-                        this_cpu, now - touch_timestamp,
+                        this_cpu, now - touch_ts,
                         current->comm, task_pid_nr(current));
         print_modules();
         print_irqtrace_events(current);
@@ -209,32 +209,32 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
         switch (action) {
         case CPU_UP_PREPARE:
         case CPU_UP_PREPARE_FROZEN:
-                BUG_ON(per_cpu(watchdog_task, hotcpu));
+                BUG_ON(per_cpu(softlockup_watchdog, hotcpu));
                 p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu);
                 if (IS_ERR(p)) {
                         printk(KERN_ERR "watchdog for %i failed\n", hotcpu);
                         return NOTIFY_BAD;
                 }
-                per_cpu(touch_timestamp, hotcpu) = 0;
-                per_cpu(watchdog_task, hotcpu) = p;
+                per_cpu(softlockup_touch_ts, hotcpu) = 0;
+                per_cpu(softlockup_watchdog, hotcpu) = p;
                 kthread_bind(p, hotcpu);
                 break;
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
-                wake_up_process(per_cpu(watchdog_task, hotcpu));
+                wake_up_process(per_cpu(softlockup_watchdog, hotcpu));
                 break;
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_UP_CANCELED:
         case CPU_UP_CANCELED_FROZEN:
-                if (!per_cpu(watchdog_task, hotcpu))
+                if (!per_cpu(softlockup_watchdog, hotcpu))
                         break;
                 /* Unbind so it can run.  Fall thru. */
-                kthread_bind(per_cpu(watchdog_task, hotcpu),
+                kthread_bind(per_cpu(softlockup_watchdog, hotcpu),
                              cpumask_any(cpu_online_mask));
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
-                p = per_cpu(watchdog_task, hotcpu);
-                per_cpu(watchdog_task, hotcpu) = NULL;
+                p = per_cpu(softlockup_watchdog, hotcpu);
+                per_cpu(softlockup_watchdog, hotcpu) = NULL;
                 kthread_stop(p);
                 break;
 #endif /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
index ee5681f8d7e..63b117e9eba 100644
--- a/kernel/time/timer_stats.c
+++ b/kernel/time/timer_stats.c
@@ -86,7 +86,7 @@ static DEFINE_SPINLOCK(table_lock);
 /*
  * Per-CPU lookup locks for fast hash lookup:
  */
-static DEFINE_PER_CPU(spinlock_t, lookup_lock);
+static DEFINE_PER_CPU(spinlock_t, tstats_lookup_lock);
 
 /*
  * Mutex to serialize state changes with show-stats activities:
@@ -245,7 +245,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
         if (likely(!timer_stats_active))
                 return;
 
-        lock = &per_cpu(lookup_lock, raw_smp_processor_id());
+        lock = &per_cpu(tstats_lookup_lock, raw_smp_processor_id());
 
         input.timer = timer;
         input.start_func = startf;
@@ -348,9 +348,10 @@ static void sync_access(void)
         int cpu;
 
         for_each_online_cpu(cpu) {
-                spin_lock_irqsave(&per_cpu(lookup_lock, cpu), flags);
+                spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
+                spin_lock_irqsave(lock, flags);
                 /* nothing */
-                spin_unlock_irqrestore(&per_cpu(lookup_lock, cpu), flags);
+                spin_unlock_irqrestore(lock, flags);
         }
 }
 
@@ -408,7 +409,7 @@ void __init init_timer_stats(void)
         int cpu;
 
         for_each_possible_cpu(cpu)
-                spin_lock_init(&per_cpu(lookup_lock, cpu));
+                spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
 }
 
 static int __init init_tstats_procfs(void)
diff --git a/mm/slab.c b/mm/slab.c
index 7dfa481c96b..211b1746c63 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 c81321f9fee..dad2327e458 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));
 }
 
 /*