[PATCH] rcupdate: move synchronize_sched() back to rcupdate.c

From: Lai Jiangshan
Date: Tue Nov 04 2008 - 03:29:08 EST


this fix will increase about several hundred bytes to the kernel text
for rcuclassic.

but it will increase readability for rcupdate codes. and make
code tools happy(ctags, kernel-doc ...).

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
index 5f89b62..1d20922 100644
--- a/include/linux/rcuclassic.h
+++ b/include/linux/rcuclassic.h
@@ -166,8 +166,6 @@ extern struct lockdep_map rcu_lock_map;
local_bh_enable(); \
} while (0)

-#define __synchronize_sched() synchronize_rcu()
-
#define call_rcu_sched(head, func) call_rcu(head, func)

extern void __rcu_init(void);
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 86f1f5e..d2b5232 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -189,45 +189,6 @@ struct rcu_head {
(p) = (v); \
})

-/* Infrastructure to implement the synchronize_() primitives. */
-
-struct rcu_synchronize {
- struct rcu_head head;
- struct completion completion;
-};
-
-extern void wakeme_after_rcu(struct rcu_head *head);
-
-#define synchronize_rcu_xxx(name, func) \
-void name(void) \
-{ \
- struct rcu_synchronize rcu; \
- \
- init_completion(&rcu.completion); \
- /* Will wake me after RCU finished. */ \
- func(&rcu.head, wakeme_after_rcu); \
- /* Wait for it. */ \
- wait_for_completion(&rcu.completion); \
-}
-
-/**
- * synchronize_sched - block until all CPUs have exited any non-preemptive
- * kernel code sequences.
- *
- * This means that all preempt_disable code sequences, including NMI and
- * hardware-interrupt handlers, in progress on entry will have completed
- * before this primitive returns. However, this does not guarantee that
- * softirq handlers will have completed, since in some kernels, these
- * handlers can run in process context, and can block.
- *
- * This primitive provides the guarantees made by the (now removed)
- * synchronize_kernel() API. In contrast, synchronize_rcu() only
- * guarantees that rcu_read_lock() sections will have completed.
- * In "classic RCU", these two guarantees happen to be one and
- * the same, but can differ in realtime RCU implementations.
- */
-#define synchronize_sched() __synchronize_sched()
-
/**
* call_rcu - Queue an RCU callback for invocation after a grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -265,6 +226,7 @@ extern void call_rcu_bh(struct rcu_head *head,

/* Exported common interfaces */
extern void synchronize_rcu(void);
+extern void synchronize_sched(void);
extern void rcu_barrier(void);
extern void rcu_barrier_bh(void);
extern void rcu_barrier_sched(void);
diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h
index 3e05c09..448cd23 100644
--- a/include/linux/rcupreempt.h
+++ b/include/linux/rcupreempt.h
@@ -87,8 +87,6 @@ extern int rcu_needs_cpu(int cpu);
#define __rcu_read_lock_bh() { rcu_read_lock(); local_bh_disable(); }
#define __rcu_read_unlock_bh() { local_bh_enable(); rcu_read_unlock(); }

-extern void __synchronize_sched(void);
-
extern void __rcu_init(void);
extern void rcu_init_sched(void);
extern void rcu_check_callbacks(int cpu, int user);
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index ad63af8..bd7d6b2 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -56,11 +56,16 @@ static atomic_t rcu_barrier_cpu_count;
static DEFINE_MUTEX(rcu_barrier_mutex);
static struct completion rcu_barrier_completion;

+struct rcu_synchronize {
+ struct rcu_head head;
+ struct completion completion;
+};
+
/*
* Awaken the corresponding synchronize_rcu() instance now that a
* grace period has elapsed.
*/
-void wakeme_after_rcu(struct rcu_head *head)
+static void wakeme_after_rcu(struct rcu_head *head)
{
struct rcu_synchronize *rcu;

@@ -77,10 +82,46 @@ void wakeme_after_rcu(struct rcu_head *head)
* sections are delimited by rcu_read_lock() and rcu_read_unlock(),
* and may be nested.
*/
-void synchronize_rcu(void); /* Makes kernel-doc tools happy */
-synchronize_rcu_xxx(synchronize_rcu, call_rcu)
+void synchronize_rcu(void)
+{
+ struct rcu_synchronize rcu;
+
+ init_completion(&rcu.completion);
+ /* Will wake me after RCU finished. */
+ call_rcu(&rcu.head, wakeme_after_rcu);
+ /* Wait for it. */
+ wait_for_completion(&rcu.completion);
+}
EXPORT_SYMBOL_GPL(synchronize_rcu);

+/**
+ * synchronize_sched - block until all CPUs have exited any non-preemptive
+ * kernel code sequences.
+ *
+ * This means that all preempt_disable code sequences, including NMI and
+ * hardware-interrupt handlers, in progress on entry will have completed
+ * before this primitive returns. However, this does not guarantee that
+ * softirq handlers will have completed, since in some kernels, these
+ * handlers can run in process context, and can block.
+ *
+ * This primitive provides the guarantees made by the (now removed)
+ * synchronize_kernel() API. In contrast, synchronize_rcu() only
+ * guarantees that rcu_read_lock() sections will have completed.
+ * In "classic RCU", these two guarantees happen to be one and
+ * the same, but can differ in realtime RCU implementations.
+ */
+void synchronize_sched(void)
+{
+ struct rcu_synchronize rcu;
+
+ init_completion(&rcu.completion);
+ /* Will wake me after RCU finished. */
+ call_rcu_sched(&rcu.head, wakeme_after_rcu);
+ /* Wait for it. */
+ wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_sched);
+
static void rcu_barrier_callback(struct rcu_head *notused)
{
if (atomic_dec_and_test(&rcu_barrier_cpu_count))
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index 59236e8..2068ad9 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -1161,15 +1161,6 @@ void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
EXPORT_SYMBOL_GPL(call_rcu_sched);

/*
- * Wait until all currently running preempt_disable() code segments
- * (including hardware-irq-disable segments) complete. Note that
- * in -rt this does -not- necessarily result in all currently executing
- * interrupt -handlers- having completed.
- */
-synchronize_rcu_xxx(__synchronize_sched, call_rcu_sched)
-EXPORT_SYMBOL_GPL(__synchronize_sched);
-
-/*
* kthread function that manages call_rcu_sched grace periods.
*/
static int rcu_sched_grace_period(void *arg)


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