[PATCH 3/7] percpu: clean up percpu variable definitions

[Tejun Heo <tj@kernel.org>]

Percpu variable definition is about to be updated such that no static
declaration is allowed.  Update percpu variable definitions
accoringly.

* as,cfq: rename ioc_count uniquely

* cpufreq: rename cpu_dbs_info uniquely

* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it

* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and
  rename it

* ipv4,6: rename cookie_scratch uniquely

While at it, make cris:use DECLARE_PER_CPU() instead of extern
volatile DEFINE_PER_CPU() for declaration.

[ Impact: percpu usage cleanups, no duplicate static percpu var names ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: David S. Miller <davem@davemloft.net>
---
 arch/cris/include/asm/mmu_context.h    |    2 +-
 block/as-iosched.c                     |   10 +++++-----
 block/cfq-iosched.c                    |   10 +++++-----
 drivers/cpufreq/cpufreq_conservative.c |   12 ++++++------
 drivers/cpufreq/cpufreq_ondemand.c     |   15 ++++++++-------
 drivers/xen/events.c                   |    9 +++++----
 mm/page-writeback.c                    |    5 +++--
 net/ipv4/syncookies.c                  |    5 +++--
 net/ipv6/syncookies.c                  |    5 +++--
 9 files changed, 39 insertions(+), 34 deletions(-)

diff --git a/arch/cris/include/asm/mmu_context.h b/arch/cris/include/asm/mmu_context.h
index 72ba08d..00de1a0 100644
--- a/arch/cris/include/asm/mmu_context.h
+++ b/arch/cris/include/asm/mmu_context.h
@@ -17,7 +17,7 @@ extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  * registers like cr3 on the i386
  */
 
-extern volatile DEFINE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
+DECLARE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
diff --git a/block/as-iosched.c b/block/as-iosched.c
index c48fa67..96ff4d1 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -146,7 +146,7 @@ enum arq_state {
 #define RQ_STATE(rq)	((enum arq_state)(rq)->elevator_private2)
 #define RQ_SET_STATE(rq, state)	((rq)->elevator_private2 = (void *) state)
 
-static DEFINE_PER_CPU(unsigned long, ioc_count);
+static DEFINE_PER_CPU(unsigned long, as_ioc_count);
 static struct completion *ioc_gone;
 static DEFINE_SPINLOCK(ioc_gone_lock);
 
@@ -161,7 +161,7 @@ static void as_antic_stop(struct as_data *ad);
 static void free_as_io_context(struct as_io_context *aic)
 {
 	kfree(aic);
-	elv_ioc_count_dec(ioc_count);
+	elv_ioc_count_dec(as_ioc_count);
 	if (ioc_gone) {
 		/*
 		 * AS scheduler is exiting, grab exit lock and check
@@ -169,7 +169,7 @@ static void free_as_io_context(struct as_io_context *aic)
 		 * complete ioc_gone and set it back to NULL.
 		 */
 		spin_lock(&ioc_gone_lock);
-		if (ioc_gone && !elv_ioc_count_read(ioc_count)) {
+		if (ioc_gone && !elv_ioc_count_read(as_ioc_count)) {
 			complete(ioc_gone);
 			ioc_gone = NULL;
 		}
@@ -211,7 +211,7 @@ static struct as_io_context *alloc_as_io_context(void)
 		ret->seek_total = 0;
 		ret->seek_samples = 0;
 		ret->seek_mean = 0;
-		elv_ioc_count_inc(ioc_count);
+		elv_ioc_count_inc(as_ioc_count);
 	}
 
 	return ret;
@@ -1509,7 +1509,7 @@ static void __exit as_exit(void)
 	ioc_gone = &all_gone;
 	/* ioc_gone's update must be visible before reading ioc_count */
 	smp_wmb();
-	if (elv_ioc_count_read(ioc_count))
+	if (elv_ioc_count_read(as_ioc_count))
 		wait_for_completion(&all_gone);
 	synchronize_rcu();
 }
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index a55a9bd..deea748 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -48,7 +48,7 @@ static int cfq_slice_idle = HZ / 125;
 static struct kmem_cache *cfq_pool;
 static struct kmem_cache *cfq_ioc_pool;
 
-static DEFINE_PER_CPU(unsigned long, ioc_count);
+static DEFINE_PER_CPU(unsigned long, cfq_ioc_count);
 static struct completion *ioc_gone;
 static DEFINE_SPINLOCK(ioc_gone_lock);
 
@@ -1423,7 +1423,7 @@ static void cfq_cic_free_rcu(struct rcu_head *head)
 	cic = container_of(head, struct cfq_io_context, rcu_head);
 
 	kmem_cache_free(cfq_ioc_pool, cic);
-	elv_ioc_count_dec(ioc_count);
+	elv_ioc_count_dec(cfq_ioc_count);
 
 	if (ioc_gone) {
 		/*
@@ -1432,7 +1432,7 @@ static void cfq_cic_free_rcu(struct rcu_head *head)
 		 * complete ioc_gone and set it back to NULL
 		 */
 		spin_lock(&ioc_gone_lock);
-		if (ioc_gone && !elv_ioc_count_read(ioc_count)) {
+		if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) {
 			complete(ioc_gone);
 			ioc_gone = NULL;
 		}
@@ -1558,7 +1558,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 		INIT_HLIST_NODE(&cic->cic_list);
 		cic->dtor = cfq_free_io_context;
 		cic->exit = cfq_exit_io_context;
-		elv_ioc_count_inc(ioc_count);
+		elv_ioc_count_inc(cfq_ioc_count);
 	}
 
 	return cic;
@@ -2663,7 +2663,7 @@ static void __exit cfq_exit(void)
 	 * this also protects us from entering cfq_slab_kill() with
 	 * pending RCU callbacks
 	 */
-	if (elv_ioc_count_read(ioc_count))
+	if (elv_ioc_count_read(cfq_ioc_count))
 		wait_for_completion(&all_gone);
 	cfq_slab_kill();
 }
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 7a74d17..8191d04 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -80,7 +80,7 @@ struct cpu_dbs_info_s {
 	int cpu;
 	unsigned int enable:1;
 };
-static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info);
 
 static unsigned int dbs_enable;	/* number of CPUs using this policy */
 
@@ -153,7 +153,7 @@ dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
 		     void *data)
 {
 	struct cpufreq_freqs *freq = data;
-	struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
+	struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info,
 							freq->cpu);
 
 	struct cpufreq_policy *policy;
@@ -326,7 +326,7 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
 	/* we need to re-evaluate prev_cpu_idle */
 	for_each_online_cpu(j) {
 		struct cpu_dbs_info_s *dbs_info;
-		dbs_info = &per_cpu(cpu_dbs_info, j);
+		dbs_info = &per_cpu(cs_cpu_dbs_info, j);
 		dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
 						&dbs_info->prev_cpu_wall);
 		if (dbs_tuners_ins.ignore_nice)
@@ -416,7 +416,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 		cputime64_t cur_wall_time, cur_idle_time;
 		unsigned int idle_time, wall_time;
 
-		j_dbs_info = &per_cpu(cpu_dbs_info, j);
+		j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
 
 		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
 
@@ -556,7 +556,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 	unsigned int j;
 	int rc;
 
-	this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
+	this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
 
 	switch (event) {
 	case CPUFREQ_GOV_START:
@@ -576,7 +576,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 		for_each_cpu(j, policy->cpus) {
 			struct cpu_dbs_info_s *j_dbs_info;
-			j_dbs_info = &per_cpu(cpu_dbs_info, j);
+			j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
 			j_dbs_info->cur_policy = policy;
 
 			j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index e741c33..04de476 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -87,7 +87,7 @@ struct cpu_dbs_info_s {
 	unsigned int enable:1,
 		sample_type:1;
 };
-static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info);
 
 static unsigned int dbs_enable;	/* number of CPUs using this policy */
 
@@ -165,7 +165,8 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
 	unsigned int freq_hi, freq_lo;
 	unsigned int index = 0;
 	unsigned int jiffies_total, jiffies_hi, jiffies_lo;
-	struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, policy->cpu);
+	struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
+						   policy->cpu);
 
 	if (!dbs_info->freq_table) {
 		dbs_info->freq_lo = 0;
@@ -210,7 +211,7 @@ static void ondemand_powersave_bias_init(void)
 {
 	int i;
 	for_each_online_cpu(i) {
-		struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, i);
+		struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, i);
 		dbs_info->freq_table = cpufreq_frequency_get_table(i);
 		dbs_info->freq_lo = 0;
 	}
@@ -325,7 +326,7 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
 	/* we need to re-evaluate prev_cpu_idle */
 	for_each_online_cpu(j) {
 		struct cpu_dbs_info_s *dbs_info;
-		dbs_info = &per_cpu(cpu_dbs_info, j);
+		dbs_info = &per_cpu(od_cpu_dbs_info, j);
 		dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
 						&dbs_info->prev_cpu_wall);
 		if (dbs_tuners_ins.ignore_nice)
@@ -419,7 +420,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 		unsigned int load, load_freq;
 		int freq_avg;
 
-		j_dbs_info = &per_cpu(cpu_dbs_info, j);
+		j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
 
 		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
 
@@ -576,7 +577,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 	unsigned int j;
 	int rc;
 
-	this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
+	this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
 
 	switch (event) {
 	case CPUFREQ_GOV_START:
@@ -598,7 +599,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 		for_each_cpu(j, policy->cpus) {
 			struct cpu_dbs_info_s *j_dbs_info;
-			j_dbs_info = &per_cpu(cpu_dbs_info, j);
+			j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
 			j_dbs_info->cur_policy = policy;
 
 			j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 228a8bb..dbfed85 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -596,6 +596,8 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static DEFINE_PER_CPU(unsigned, xed_nesting_count);
+
 /*
  * Search the CPUs pending events bitmasks.  For each one found, map
  * the event number to an irq, and feed it into do_IRQ() for
@@ -611,7 +613,6 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 	struct pt_regs *old_regs = set_irq_regs(regs);
 	struct shared_info *s = HYPERVISOR_shared_info;
 	struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
-	static DEFINE_PER_CPU(unsigned, nesting_count);
  	unsigned count;
 
 	exit_idle();
@@ -622,7 +623,7 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 
 		vcpu_info->evtchn_upcall_pending = 0;
 
-		if (__get_cpu_var(nesting_count)++)
+		if (__get_cpu_var(xed_nesting_count)++)
 			goto out;
 
 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
@@ -647,8 +648,8 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 
 		BUG_ON(!irqs_disabled());
 
-		count = __get_cpu_var(nesting_count);
-		__get_cpu_var(nesting_count) = 0;
+		count = __get_cpu_var(xed_nesting_count);
+		__get_cpu_var(xed_nesting_count) = 0;
 	} while(count != 1);
 
 out:
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index bb553c3..0e0c9de 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -606,6 +606,8 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
 	}
 }
 
+static DEFINE_PER_CPU(unsigned long, bdp_ratelimits) = 0;
+
 /**
  * balance_dirty_pages_ratelimited_nr - balance dirty memory state
  * @mapping: address_space which was dirtied
@@ -623,7 +625,6 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 					unsigned long nr_pages_dirtied)
 {
-	static DEFINE_PER_CPU(unsigned long, ratelimits) = 0;
 	unsigned long ratelimit;
 	unsigned long *p;
 
@@ -636,7 +637,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 	 * tasks in balance_dirty_pages(). Period.
 	 */
 	preempt_disable();
-	p =  &__get_cpu_var(ratelimits);
+	p =  &__get_cpu_var(bdp_ratelimits);
 	*p += nr_pages_dirtied;
 	if (unlikely(*p >= ratelimit)) {
 		*p = 0;
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index ce629ed..a3c045c 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -37,12 +37,13 @@ __initcall(init_syncookies);
 #define COOKIEBITS 24	/* Upper bits store count */
 #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
 
-static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS], cookie_scratch);
+static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS],
+		      ipv4_cookie_scratch);
 
 static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
 		       u32 count, int c)
 {
-	__u32 *tmp = __get_cpu_var(cookie_scratch);
+	__u32 *tmp = __get_cpu_var(ipv4_cookie_scratch);
 
 	memcpy(tmp + 4, syncookie_secret[c], sizeof(syncookie_secret[c]));
 	tmp[0] = (__force u32)saddr;
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 4d995fe..e2bcff0 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -74,12 +74,13 @@ static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
 	return child;
 }
 
-static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS], cookie_scratch);
+static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS],
+		      ipv6_cookie_scratch);
 
 static u32 cookie_hash(struct in6_addr *saddr, struct in6_addr *daddr,
 		       __be16 sport, __be16 dport, u32 count, int c)
 {
-	__u32 *tmp = __get_cpu_var(cookie_scratch);
+	__u32 *tmp = __get_cpu_var(ipv6_cookie_scratch);
 
 	/*
 	 * we have 320 bits of information to hash, copy in the remaining
-- 
1.6.0.2