generic-ipi: cleanups

Andrew pointed out that there's some small amount of style rot in kernel/smp.c. Clean it up. Reported-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>

generic-ipi: cleanups
Andrew pointed out that there's some small amount of style rot in kernel/smp.c. Clean it up. Reported-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar
1 parent 6e2756376c
Showing 1 changed file with 86 additions and 76 deletions Side-by-side Diff
kernel/smp.c
@@ -2,13 +2,12 @@
  * Generic helpers for smp ipi calls
  *
  * (C) Jens Axboe <jens.axboe@oracle.com> 2008
- *
  */
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/percpu.h>
 #include <linux/rcupdate.h>
 #include <linux/rculist.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>
  
  
  
  
@@ -17,29 +16,30 @@
 static struct {
 	struct list_head	queue;
 	spinlock_t		lock;
-} call_function __cacheline_aligned_in_smp = {
-	.queue = LIST_HEAD_INIT(call_function.queue),
-	.lock  = __SPIN_LOCK_UNLOCKED(call_function.lock),
-};
+} call_function __cacheline_aligned_in_smp =
+	{
+		.queue		= LIST_HEAD_INIT(call_function.queue),
+		.lock		= __SPIN_LOCK_UNLOCKED(call_function.lock),
+	};
  
 enum {
 	CSD_FLAG_LOCK		= 0x01,
 };
  
 struct call_function_data {
-	struct call_single_data csd;
-	spinlock_t lock;
-	unsigned int refs;
-	cpumask_var_t cpumask;
+	struct call_single_data	csd;
+	spinlock_t		lock;
+	unsigned int		refs;
+	cpumask_var_t		cpumask;
 };
  
 struct call_single_queue {
-	struct list_head list;
-	spinlock_t lock;
+	struct list_head	list;
+	spinlock_t		lock;
 };
  
 static DEFINE_PER_CPU(struct call_function_data, cfd_data) = {
-	.lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock),
+	.lock			= __SPIN_LOCK_UNLOCKED(cfd_data.lock),
 };
  
 static int
@@ -71,7 +71,7 @@
 }
  
 static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
-	.notifier_call = hotplug_cfd,
+	.notifier_call		= hotplug_cfd,
 };
  
 static int __cpuinit init_call_single_data(void)
@@ -96,9 +96,9 @@
 /*
  * csd_lock/csd_unlock used to serialize access to per-cpu csd resources
  *
- * For non-synchronous ipi calls the csd can still be in use by the previous
- * function call. For multi-cpu calls its even more interesting as we'll have
- * to ensure no other cpu is observing our csd.
+ * For non-synchronous ipi calls the csd can still be in use by the
+ * previous function call. For multi-cpu calls its even more interesting
+ * as we'll have to ensure no other cpu is observing our csd.
  */
 static void csd_lock_wait(struct call_single_data *data)
 {
  
  
  
  
  
@@ -112,27 +112,29 @@
 	data->flags = CSD_FLAG_LOCK;
  
 	/*
-	 * prevent CPU from reordering the above assignment to ->flags
-	 * with any subsequent assignments to other fields of the
-	 * specified call_single_data structure.
+	 * prevent CPU from reordering the above assignment
+	 * to ->flags with any subsequent assignments to other
+	 * fields of the specified call_single_data structure:
 	 */
-
 	smp_mb();
 }
  
 static void csd_unlock(struct call_single_data *data)
 {
 	WARN_ON(!(data->flags & CSD_FLAG_LOCK));
+
 	/*
-	 * ensure we're all done before releasing data
+	 * ensure we're all done before releasing data:
 	 */
 	smp_mb();
+
 	data->flags &= ~CSD_FLAG_LOCK;
 }
  
 /*
- * Insert a previously allocated call_single_data element for execution
- * on the given CPU. data must already have ->func, ->info, and ->flags set.
+ * Insert a previously allocated call_single_data element
+ * for execution on the given CPU. data must already have
+ * ->func, ->info, and ->flags set.
  */
 static
 void generic_exec_single(int cpu, struct call_single_data *data, int wait)
  
@@ -154,10 +156,9 @@
 	 * If IPIs can go out of order to the cache coherency protocol
 	 * in an architecture, sufficient synchronisation should be added
 	 * to arch code to make it appear to obey cache coherency WRT
-	 * locking and barrier primitives. Generic code isn't really equipped
-	 * to do the right thing...
+	 * locking and barrier primitives. Generic code isn't really
+	 * equipped to do the right thing...
 	 */
-
 	if (ipi)
 		arch_send_call_function_single_ipi(cpu);
  
@@ -183,8 +184,8 @@
 	smp_mb();
  
 	/*
-	 * It's ok to use list_for_each_rcu() here even though we may delete
-	 * 'pos', since list_del_rcu() doesn't clear ->next
+	 * It's ok to use list_for_each_rcu() here even though we may
+	 * delete 'pos', since list_del_rcu() doesn't clear ->next
 	 */
 	list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
 		int refs;
  
  
@@ -219,14 +220,14 @@
 }
  
 /*
- * Invoked by arch to handle an IPI for call function single. Must be called
- * from the arch with interrupts disabled.
+ * Invoked by arch to handle an IPI for call function single. Must be
+ * called from the arch with interrupts disabled.
  */
 void generic_smp_call_function_single_interrupt(void)
 {
 	struct call_single_queue *q = &__get_cpu_var(call_single_queue);
-	LIST_HEAD(list);
 	unsigned int data_flags;
+	LIST_HEAD(list);
  
 	spin_lock(&q->lock);
 	list_replace_init(&q->list, &list);
  
  
@@ -235,22 +236,20 @@
 	while (!list_empty(&list)) {
 		struct call_single_data *data;
  
-		data = list_entry(list.next, struct call_single_data,
-					list);
+		data = list_entry(list.next, struct call_single_data, list);
 		list_del(&data->list);
  
 		/*
-		 * 'data' can be invalid after this call if
-		 * flags == 0 (when called through
-		 * generic_exec_single(), so save them away before
-		 * making the call.
+		 * 'data' can be invalid after this call if flags == 0
+		 * (when called through generic_exec_single()),
+		 * so save them away before making the call:
 		 */
 		data_flags = data->flags;
  
 		data->func(data->info);
  
 		/*
-		 * Unlocked CSDs are valid through generic_exec_single()
+		 * Unlocked CSDs are valid through generic_exec_single():
 		 */
 		if (data_flags & CSD_FLAG_LOCK)
 			csd_unlock(data);
  
  
  
  
  
  
  
@@ -276,34 +275,41 @@
 		.flags = 0,
 	};
 	unsigned long flags;
-	/* prevent preemption and reschedule on another processor,
-	   as well as CPU removal */
-	int me = get_cpu();
+	int this_cpu;
 	int err = 0;
  
+	/*
+	 * prevent preemption and reschedule on another processor,
+	 * as well as CPU removal
+	 */
+	this_cpu = get_cpu();
+
 	/* Can deadlock when called with interrupts disabled */
 	WARN_ON(irqs_disabled());
  
-	if (cpu == me) {
+	if (cpu == this_cpu) {
 		local_irq_save(flags);
 		func(info);
 		local_irq_restore(flags);
-	} else if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
-		struct call_single_data *data = &d;
+	} else {
+		if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
+			struct call_single_data *data = &d;
  
-		if (!wait)
-			data = &__get_cpu_var(csd_data);
+			if (!wait)
+				data = &__get_cpu_var(csd_data);
  
-		csd_lock(data);
+			csd_lock(data);
  
-		data->func = func;
-		data->info = info;
-		generic_exec_single(cpu, data, wait);
-	} else {
-		err = -ENXIO;	/* CPU not online */
+			data->func = func;
+			data->info = info;
+			generic_exec_single(cpu, data, wait);
+		} else {
+			err = -ENXIO;	/* CPU not online */
+		}
 	}
  
 	put_cpu();
+
 	return err;
 }
 EXPORT_SYMBOL(smp_call_function_single);
@@ -313,10 +319,9 @@
  * @cpu: The CPU to run on.
  * @data: Pre-allocated and setup data structure
  *
- * Like smp_call_function_single(), but allow caller to pass in a pre-allocated
- * data structure. Useful for embedding @data inside other structures, for
- * instance.
- *
+ * Like smp_call_function_single(), but allow caller to pass in a
+ * pre-allocated data structure. Useful for embedding @data inside
+ * other structures, for instance.
  */
 void __smp_call_function_single(int cpu, struct call_single_data *data,
 				int wait)
  
@@ -329,10 +334,11 @@
 	generic_exec_single(cpu, data, wait);
 }
  
-/* FIXME: Shim for archs using old arch_send_call_function_ipi API. */
+/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */
+
 #ifndef arch_send_call_function_ipi_mask
-#define arch_send_call_function_ipi_mask(maskp) \
-	arch_send_call_function_ipi(*(maskp))
+# define arch_send_call_function_ipi_mask(maskp) \
+	 arch_send_call_function_ipi(*(maskp))
 #endif
  
 /**
@@ -340,7 +346,8 @@
  * @mask: The set of cpus to run on (only runs on online subset).
  * @func: The function to run. This must be fast and non-blocking.
  * @info: An arbitrary pointer to pass to the function.
- * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ * @wait: If true, wait (atomically) until function has completed
+ *        on other CPUs.
  *
  * If @wait is true, then returns once @func has returned. Note that @wait
  * will be implicitly turned on in case of allocation failures, since
  
  
  
  
  
@@ -351,27 +358,27 @@
  * must be disabled when calling this function.
  */
 void smp_call_function_many(const struct cpumask *mask,
-			    void (*func)(void *), void *info,
-			    bool wait)
+			    void (*func)(void *), void *info, bool wait)
 {
 	struct call_function_data *data;
 	unsigned long flags;
-	int cpu, next_cpu, me = smp_processor_id();
+	int cpu, next_cpu, this_cpu = smp_processor_id();
  
 	/* Can deadlock when called with interrupts disabled */
 	WARN_ON(irqs_disabled());
  
-	/* So, what's a CPU they want?  Ignoring this one. */
+	/* So, what's a CPU they want? Ignoring this one. */
 	cpu = cpumask_first_and(mask, cpu_online_mask);
-	if (cpu == me)
+	if (cpu == this_cpu)
 		cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
+
 	/* No online cpus?  We're done. */
 	if (cpu >= nr_cpu_ids)
 		return;
  
 	/* Do we have another CPU which isn't us? */
 	next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
-	if (next_cpu == me)
+	if (next_cpu == this_cpu)
 		next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask);
  
 	/* Fastpath: do that cpu by itself. */
  
  
  
  
@@ -387,30 +394,31 @@
 	data->csd.func = func;
 	data->csd.info = info;
 	cpumask_and(data->cpumask, mask, cpu_online_mask);
-	cpumask_clear_cpu(me, data->cpumask);
+	cpumask_clear_cpu(this_cpu, data->cpumask);
 	data->refs = cpumask_weight(data->cpumask);
  
 	spin_lock(&call_function.lock);
 	/*
 	 * Place entry at the _HEAD_ of the list, so that any cpu still
-	 * observing the entry in generic_smp_call_function_interrupt() will
-	 * not miss any other list entries.
+	 * observing the entry in generic_smp_call_function_interrupt()
+	 * will not miss any other list entries:
 	 */
 	list_add_rcu(&data->csd.list, &call_function.queue);
 	spin_unlock(&call_function.lock);
+
 	spin_unlock_irqrestore(&data->lock, flags);
  
 	/*
 	 * Make the list addition visible before sending the ipi.
-	 * (IPIs must obey or appear to obey normal Linux cache coherency
-	 * rules -- see comment in generic_exec_single).
+	 * (IPIs must obey or appear to obey normal Linux cache
+	 * coherency rules -- see comment in generic_exec_single).
 	 */
 	smp_mb();
  
 	/* Send a message to all CPUs in the map */
 	arch_send_call_function_ipi_mask(data->cpumask);
  
-	/* optionally wait for the CPUs to complete */
+	/* Optionally wait for the CPUs to complete */
 	if (wait)
 		csd_lock_wait(&data->csd);
 }
@@ -420,7 +428,8 @@
  * smp_call_function(): Run a function on all other CPUs.
  * @func: The function to run. This must be fast and non-blocking.
  * @info: An arbitrary pointer to pass to the function.
- * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ * @wait: If true, wait (atomically) until function has completed
+ *        on other CPUs.
  *
  * Returns 0.
  *
@@ -436,6 +445,7 @@
 	preempt_disable();
 	smp_call_function_many(cpu_online_mask, func, info, wait);
 	preempt_enable();
+
 	return 0;
 }
 EXPORT_SYMBOL(smp_call_function);
...	...	@@ -2,13 +2,12 @@
2	2	* Generic helpers for smp ipi calls
3	3	*
4	4	* (C) Jens Axboe <jens.axboe@oracle.com> 2008
5		- *
6	5	*/
7		-#include <linux/init.h>
8		-#include <linux/module.h>
9		-#include <linux/percpu.h>
10	6	#include <linux/rcupdate.h>
11	7	#include <linux/rculist.h>
	8	+#include <linux/module.h>
	9	+#include <linux/percpu.h>
	10	+#include <linux/init.h>
12	11	#include <linux/smp.h>
13	12	#include <linux/cpu.h>
14	13
15	14
16	15
17	16
...	...	@@ -17,29 +16,30 @@
17	16	static struct {
18	17	struct list_head queue;
19	18	spinlock_t lock;
20		-} call_function __cacheline_aligned_in_smp = {
21		- .queue = LIST_HEAD_INIT(call_function.queue),
22		- .lock = __SPIN_LOCK_UNLOCKED(call_function.lock),
23		-};
	19	+} call_function __cacheline_aligned_in_smp =
	20	+ {
	21	+ .queue = LIST_HEAD_INIT(call_function.queue),
	22	+ .lock = __SPIN_LOCK_UNLOCKED(call_function.lock),
	23	+ };
24	24
25	25	enum {
26	26	CSD_FLAG_LOCK = 0x01,
27	27	};
28	28
29	29	struct call_function_data {
30		- struct call_single_data csd;
31		- spinlock_t lock;
32		- unsigned int refs;
33		- cpumask_var_t cpumask;
	30	+ struct call_single_data csd;
	31	+ spinlock_t lock;
	32	+ unsigned int refs;
	33	+ cpumask_var_t cpumask;
34	34	};
35	35
36	36	struct call_single_queue {
37		- struct list_head list;
38		- spinlock_t lock;
	37	+ struct list_head list;
	38	+ spinlock_t lock;
39	39	};
40	40
41	41	static DEFINE_PER_CPU(struct call_function_data, cfd_data) = {
42		- .lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock),
	42	+ .lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock),
43	43	};
44	44
45	45	static int
...	...	@@ -71,7 +71,7 @@
71	71	}
72	72
73	73	static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
74		- .notifier_call = hotplug_cfd,
	74	+ .notifier_call = hotplug_cfd,
75	75	};
76	76
77	77	static int __cpuinit init_call_single_data(void)
...	...	@@ -96,9 +96,9 @@
96	96	/*
97	97	* csd_lock/csd_unlock used to serialize access to per-cpu csd resources
98	98	*
99		- * For non-synchronous ipi calls the csd can still be in use by the previous
100		- * function call. For multi-cpu calls its even more interesting as we'll have
101		- * to ensure no other cpu is observing our csd.
	99	+ * For non-synchronous ipi calls the csd can still be in use by the
	100	+ * previous function call. For multi-cpu calls its even more interesting
	101	+ * as we'll have to ensure no other cpu is observing our csd.
102	102	*/
103	103	static void csd_lock_wait(struct call_single_data *data)
104	104	{
105	105
106	106
107	107
108	108
109	109
...	...	@@ -112,27 +112,29 @@
112	112	data->flags = CSD_FLAG_LOCK;
113	113
114	114	/*
115		- * prevent CPU from reordering the above assignment to ->flags
116		- * with any subsequent assignments to other fields of the
117		- * specified call_single_data structure.
	115	+ * prevent CPU from reordering the above assignment
	116	+ * to ->flags with any subsequent assignments to other
	117	+ * fields of the specified call_single_data structure:
118	118	*/
119		-
120	119	smp_mb();
121	120	}
122	121
123	122	static void csd_unlock(struct call_single_data *data)
124	123	{
125	124	WARN_ON(!(data->flags & CSD_FLAG_LOCK));
	125	+
126	126	/*
127		- * ensure we're all done before releasing data
	127	+ * ensure we're all done before releasing data:
128	128	*/
129	129	smp_mb();
	130	+
130	131	data->flags &= ~CSD_FLAG_LOCK;
131	132	}
132	133
133	134	/*
134		- * Insert a previously allocated call_single_data element for execution
135		- * on the given CPU. data must already have ->func, ->info, and ->flags set.
	135	+ * Insert a previously allocated call_single_data element
	136	+ * for execution on the given CPU. data must already have
	137	+ * ->func, ->info, and ->flags set.
136	138	*/
137	139	static
138	140	void generic_exec_single(int cpu, struct call_single_data *data, int wait)
139	141
...	...	@@ -154,10 +156,9 @@
154	156	* If IPIs can go out of order to the cache coherency protocol
155	157	* in an architecture, sufficient synchronisation should be added
156	158	* to arch code to make it appear to obey cache coherency WRT
157		- * locking and barrier primitives. Generic code isn't really equipped
158		- * to do the right thing...
	159	+ * locking and barrier primitives. Generic code isn't really
	160	+ * equipped to do the right thing...
159	161	*/
160		-
161	162	if (ipi)
162	163	arch_send_call_function_single_ipi(cpu);
163	164
...	...	@@ -183,8 +184,8 @@
183	184	smp_mb();
184	185
185	186	/*
186		- * It's ok to use list_for_each_rcu() here even though we may delete
187		- * 'pos', since list_del_rcu() doesn't clear ->next
	187	+ * It's ok to use list_for_each_rcu() here even though we may
	188	+ * delete 'pos', since list_del_rcu() doesn't clear ->next
188	189	*/
189	190	list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
190	191	int refs;
191	192
192	193
...	...	@@ -219,14 +220,14 @@
219	220	}
220	221
221	222	/*
222		- * Invoked by arch to handle an IPI for call function single. Must be called
223		- * from the arch with interrupts disabled.
	223	+ * Invoked by arch to handle an IPI for call function single. Must be
	224	+ * called from the arch with interrupts disabled.
224	225	*/
225	226	void generic_smp_call_function_single_interrupt(void)
226	227	{
227	228	struct call_single_queue *q = &__get_cpu_var(call_single_queue);
228		- LIST_HEAD(list);
229	229	unsigned int data_flags;
	230	+ LIST_HEAD(list);
230	231
231	232	spin_lock(&q->lock);
232	233	list_replace_init(&q->list, &list);
233	234
234	235
...	...	@@ -235,22 +236,20 @@
235	236	while (!list_empty(&list)) {
236	237	struct call_single_data *data;
237	238
238		- data = list_entry(list.next, struct call_single_data,
239		- list);
	239	+ data = list_entry(list.next, struct call_single_data, list);
240	240	list_del(&data->list);
241	241
242	242	/*
243		- * 'data' can be invalid after this call if
244		- * flags == 0 (when called through
245		- * generic_exec_single(), so save them away before
246		- * making the call.
	243	+ * 'data' can be invalid after this call if flags == 0
	244	+ * (when called through generic_exec_single()),
	245	+ * so save them away before making the call:
247	246	*/
248	247	data_flags = data->flags;
249	248
250	249	data->func(data->info);
251	250
252	251	/*
253		- * Unlocked CSDs are valid through generic_exec_single()
	252	+ * Unlocked CSDs are valid through generic_exec_single():
254	253	*/
255	254	if (data_flags & CSD_FLAG_LOCK)
256	255	csd_unlock(data);
257	256
258	257
259	258
260	259
261	260
262	261
263	262
...	...	@@ -276,34 +275,41 @@
276	275	.flags = 0,
277	276	};
278	277	unsigned long flags;
279		- /* prevent preemption and reschedule on another processor,
280		- as well as CPU removal */
281		- int me = get_cpu();
	278	+ int this_cpu;
282	279	int err = 0;
283	280
	281	+ /*
	282	+ * prevent preemption and reschedule on another processor,
	283	+ * as well as CPU removal
	284	+ */
	285	+ this_cpu = get_cpu();
	286	+
284	287	/* Can deadlock when called with interrupts disabled */
285	288	WARN_ON(irqs_disabled());
286	289
287		- if (cpu == me) {
	290	+ if (cpu == this_cpu) {
288	291	local_irq_save(flags);
289	292	func(info);
290	293	local_irq_restore(flags);
291		- } else if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
292		- struct call_single_data *data = &d;
	294	+ } else {
	295	+ if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
	296	+ struct call_single_data *data = &d;
293	297
294		- if (!wait)
295		- data = &__get_cpu_var(csd_data);
	298	+ if (!wait)
	299	+ data = &__get_cpu_var(csd_data);
296	300
297		- csd_lock(data);
	301	+ csd_lock(data);
298	302
299		- data->func = func;
300		- data->info = info;
301		- generic_exec_single(cpu, data, wait);
302		- } else {
303		- err = -ENXIO; /* CPU not online */
	303	+ data->func = func;
	304	+ data->info = info;
	305	+ generic_exec_single(cpu, data, wait);
	306	+ } else {
	307	+ err = -ENXIO; /* CPU not online */
	308	+ }
304	309	}
305	310
306	311	put_cpu();
	312	+
307	313	return err;
308	314	}
309	315	EXPORT_SYMBOL(smp_call_function_single);
...	...	@@ -313,10 +319,9 @@
313	319	* @cpu: The CPU to run on.
314	320	* @data: Pre-allocated and setup data structure
315	321	*
316		- * Like smp_call_function_single(), but allow caller to pass in a pre-allocated
317		- * data structure. Useful for embedding @data inside other structures, for
318		- * instance.
319		- *
	322	+ * Like smp_call_function_single(), but allow caller to pass in a
	323	+ * pre-allocated data structure. Useful for embedding @data inside
	324	+ * other structures, for instance.
320	325	*/
321	326	void __smp_call_function_single(int cpu, struct call_single_data *data,
322	327	int wait)
323	328
...	...	@@ -329,10 +334,11 @@
329	334	generic_exec_single(cpu, data, wait);
330	335	}
331	336
332		-/* FIXME: Shim for archs using old arch_send_call_function_ipi API. */
	337	+/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */
	338	+
333	339	#ifndef arch_send_call_function_ipi_mask
334		-#define arch_send_call_function_ipi_mask(maskp) \
335		- arch_send_call_function_ipi(*(maskp))
	340	+# define arch_send_call_function_ipi_mask(maskp) \
	341	+ arch_send_call_function_ipi(*(maskp))
336	342	#endif
337	343
338	344	/**
...	...	@@ -340,7 +346,8 @@
340	346	* @mask: The set of cpus to run on (only runs on online subset).
341	347	* @func: The function to run. This must be fast and non-blocking.
342	348	* @info: An arbitrary pointer to pass to the function.
343		- * @wait: If true, wait (atomically) until function has completed on other CPUs.
	349	+ * @wait: If true, wait (atomically) until function has completed
	350	+ * on other CPUs.
344	351	*
345	352	* If @wait is true, then returns once @func has returned. Note that @wait
346	353	* will be implicitly turned on in case of allocation failures, since
347	354
348	355
349	356
350	357
351	358
...	...	@@ -351,27 +358,27 @@
351	358	* must be disabled when calling this function.
352	359	*/
353	360	void smp_call_function_many(const struct cpumask *mask,
354		- void (func)(void ), void *info,
355		- bool wait)
	361	+ void (func)(void ), void *info, bool wait)
356	362	{
357	363	struct call_function_data *data;
358	364	unsigned long flags;
359		- int cpu, next_cpu, me = smp_processor_id();
	365	+ int cpu, next_cpu, this_cpu = smp_processor_id();
360	366
361	367	/* Can deadlock when called with interrupts disabled */
362	368	WARN_ON(irqs_disabled());
363	369
364		- /* So, what's a CPU they want? Ignoring this one. */
	370	+ /* So, what's a CPU they want? Ignoring this one. */
365	371	cpu = cpumask_first_and(mask, cpu_online_mask);
366		- if (cpu == me)
	372	+ if (cpu == this_cpu)
367	373	cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
	374	+
368	375	/* No online cpus? We're done. */
369	376	if (cpu >= nr_cpu_ids)
370	377	return;
371	378
372	379	/* Do we have another CPU which isn't us? */
373	380	next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
374		- if (next_cpu == me)
	381	+ if (next_cpu == this_cpu)
375	382	next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask);
376	383
377	384	/* Fastpath: do that cpu by itself. */
378	385
379	386
380	387
381	388
...	...	@@ -387,30 +394,31 @@
387	394	data->csd.func = func;
388	395	data->csd.info = info;
389	396	cpumask_and(data->cpumask, mask, cpu_online_mask);
390		- cpumask_clear_cpu(me, data->cpumask);
	397	+ cpumask_clear_cpu(this_cpu, data->cpumask);
391	398	data->refs = cpumask_weight(data->cpumask);
392	399
393	400	spin_lock(&call_function.lock);
394	401	/*
395	402	* Place entry at the _HEAD_ of the list, so that any cpu still
396		- * observing the entry in generic_smp_call_function_interrupt() will
397		- * not miss any other list entries.
	403	+ * observing the entry in generic_smp_call_function_interrupt()
	404	+ * will not miss any other list entries:
398	405	*/
399	406	list_add_rcu(&data->csd.list, &call_function.queue);
400	407	spin_unlock(&call_function.lock);
	408	+
401	409	spin_unlock_irqrestore(&data->lock, flags);
402	410
403	411	/*
404	412	* Make the list addition visible before sending the ipi.
405		- * (IPIs must obey or appear to obey normal Linux cache coherency
406		- * rules -- see comment in generic_exec_single).
	413	+ * (IPIs must obey or appear to obey normal Linux cache
	414	+ * coherency rules -- see comment in generic_exec_single).
407	415	*/
408	416	smp_mb();
409	417
410	418	/* Send a message to all CPUs in the map */
411	419	arch_send_call_function_ipi_mask(data->cpumask);
412	420
413		- /* optionally wait for the CPUs to complete */
	421	+ /* Optionally wait for the CPUs to complete */
414	422	if (wait)
415	423	csd_lock_wait(&data->csd);
416	424	}
...	...	@@ -420,7 +428,8 @@
420	428	* smp_call_function(): Run a function on all other CPUs.
421	429	* @func: The function to run. This must be fast and non-blocking.
422	430	* @info: An arbitrary pointer to pass to the function.
423		- * @wait: If true, wait (atomically) until function has completed on other CPUs.
	431	+ * @wait: If true, wait (atomically) until function has completed
	432	+ * on other CPUs.
424	433	*
425	434	* Returns 0.
426	435	*
...	...	@@ -436,6 +445,7 @@
436	445	preempt_disable();
437	446	smp_call_function_many(cpu_online_mask, func, info, wait);
438	447	preempt_enable();
	448	+
439	449	return 0;
440	450	}
441	451	EXPORT_SYMBOL(smp_call_function);