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Date: Tue, 24 Sep 2013 18:50:16 -0700
From: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To: linux-kernel@...r.kernel.org
Cc: mingo@...nel.org, laijs@...fujitsu.com, dipankar@...ibm.com,
akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
josh@...htriplett.org, niv@...ibm.com, tglx@...utronix.de,
peterz@...radead.org, rostedt@...dmis.org, dhowells@...hat.com,
edumazet@...gle.com, darren@...art.com, fweisbec@...il.com,
sbw@....edu, "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 6/6] rcu: Consistent rcu_is_watching() naming
From: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
The old rcu_is_cpu_idle() function is just __rcu_is_watching() with
preemption disabled. This commit therefore renames rcu_is_cpu_idle()
to rcu_is_watching.
Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
---
include/linux/rcupdate.h | 18 +++++++++---------
include/linux/rcutiny.h | 16 ++++++++++++----
include/linux/rcutree.h | 2 +-
kernel/lockdep.c | 4 ++--
kernel/rcupdate.c | 2 +-
kernel/rcutiny.c | 6 +++---
kernel/rcutree.c | 36 ++++++++++++++++++------------------
7 files changed, 46 insertions(+), 38 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index a53a21a..39cbb88 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -262,7 +262,7 @@ static inline void rcu_user_hooks_switch(struct task_struct *prev,
} while (0)
#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP)
-extern int rcu_is_cpu_idle(void);
+extern bool __rcu_is_watching(void);
#endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) */
/*
@@ -351,7 +351,7 @@ static inline int rcu_read_lock_held(void)
{
if (!debug_lockdep_rcu_enabled())
return 1;
- if (rcu_is_cpu_idle())
+ if (!rcu_is_watching())
return 0;
if (!rcu_lockdep_current_cpu_online())
return 0;
@@ -402,7 +402,7 @@ static inline int rcu_read_lock_sched_held(void)
if (!debug_lockdep_rcu_enabled())
return 1;
- if (rcu_is_cpu_idle())
+ if (!rcu_is_watching())
return 0;
if (!rcu_lockdep_current_cpu_online())
return 0;
@@ -771,7 +771,7 @@ static inline void rcu_read_lock(void)
__rcu_read_lock();
__acquire(RCU);
rcu_lock_acquire(&rcu_lock_map);
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_lock() used illegally while idle");
}
@@ -792,7 +792,7 @@ static inline void rcu_read_lock(void)
*/
static inline void rcu_read_unlock(void)
{
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_unlock() used illegally while idle");
rcu_lock_release(&rcu_lock_map);
__release(RCU);
@@ -821,7 +821,7 @@ static inline void rcu_read_lock_bh(void)
local_bh_disable();
__acquire(RCU_BH);
rcu_lock_acquire(&rcu_bh_lock_map);
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_lock_bh() used illegally while idle");
}
@@ -832,7 +832,7 @@ static inline void rcu_read_lock_bh(void)
*/
static inline void rcu_read_unlock_bh(void)
{
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_unlock_bh() used illegally while idle");
rcu_lock_release(&rcu_bh_lock_map);
__release(RCU_BH);
@@ -857,7 +857,7 @@ static inline void rcu_read_lock_sched(void)
preempt_disable();
__acquire(RCU_SCHED);
rcu_lock_acquire(&rcu_sched_lock_map);
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_lock_sched() used illegally while idle");
}
@@ -875,7 +875,7 @@ static inline notrace void rcu_read_lock_sched_notrace(void)
*/
static inline void rcu_read_unlock_sched(void)
{
- rcu_lockdep_assert(!rcu_is_cpu_idle(),
+ rcu_lockdep_assert(rcu_is_watching(),
"rcu_read_unlock_sched() used illegally while idle");
rcu_lock_release(&rcu_sched_lock_map);
__release(RCU_SCHED);
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index bee6659..09ebcbe 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -132,13 +132,21 @@ static inline void rcu_scheduler_starting(void)
}
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
-#ifdef CONFIG_RCU_TRACE
+#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
-static inline bool __rcu_is_watching(void)
+static inline bool rcu_is_watching(void)
{
- return !rcu_is_cpu_idle();
+ return __rcu_is_watching();
}
-#endif /* #ifdef CONFIG_RCU_TRACE */
+#else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
+
+static inline bool rcu_is_watching(void)
+{
+ return true;
+}
+
+
+#endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
#endif /* __LINUX_RCUTINY_H */
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 293613d..4b9c815 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -90,6 +90,6 @@ extern void exit_rcu(void);
extern void rcu_scheduler_starting(void);
extern int rcu_scheduler_active __read_mostly;
-extern bool __rcu_is_watching(void);
+extern bool rcu_is_watching(void);
#endif /* __LINUX_RCUTREE_H */
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index e16c45b..4e8e14c 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -4224,7 +4224,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
!rcu_lockdep_current_cpu_online()
? "RCU used illegally from offline CPU!\n"
- : rcu_is_cpu_idle()
+ : !rcu_is_watching()
? "RCU used illegally from idle CPU!\n"
: "",
rcu_scheduler_active, debug_locks);
@@ -4247,7 +4247,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
* So complain bitterly if someone does call rcu_read_lock(),
* rcu_read_lock_bh() and so on from extended quiescent states.
*/
- if (rcu_is_cpu_idle())
+ if (!rcu_is_watching())
printk("RCU used illegally from extended quiescent state!\n");
lockdep_print_held_locks(curr);
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index b02a339..3b3c046 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -148,7 +148,7 @@ int rcu_read_lock_bh_held(void)
{
if (!debug_lockdep_rcu_enabled())
return 1;
- if (rcu_is_cpu_idle())
+ if (!rcu_is_watching())
return 0;
if (!rcu_lockdep_current_cpu_online())
return 0;
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index b4bc618..0fa061d 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -179,11 +179,11 @@ EXPORT_SYMBOL_GPL(rcu_irq_enter);
/*
* Test whether RCU thinks that the current CPU is idle.
*/
-int rcu_is_cpu_idle(void)
+bool __rcu_is_watching(void)
{
- return !rcu_dynticks_nesting;
+ return rcu_dynticks_nesting;
}
-EXPORT_SYMBOL(rcu_is_cpu_idle);
+EXPORT_SYMBOL(__rcu_is_watching);
#endif /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 1b123e1..981d0c1 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -655,34 +655,34 @@ void rcu_nmi_exit(void)
}
/**
- * rcu_is_cpu_idle - see if RCU thinks that the current CPU is idle
+ * __rcu_is_watching - are RCU read-side critical sections safe?
+ *
+ * Return true if RCU is watching the running CPU, which means that
+ * this CPU can safely enter RCU read-side critical sections. Unlike
+ * rcu_is_watching(), the caller of __rcu_is_watching() must have at
+ * least disabled preemption.
+ */
+bool __rcu_is_watching(void)
+{
+ return atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1;
+}
+
+/**
+ * rcu_is_watching - see if RCU thinks that the current CPU is idle
*
* If the current CPU is in its idle loop and is neither in an interrupt
* or NMI handler, return true.
*/
-int rcu_is_cpu_idle(void)
+bool rcu_is_watching(void)
{
int ret;
preempt_disable();
- ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+ ret = __rcu_is_watching();
preempt_enable();
return ret;
}
-EXPORT_SYMBOL_GPL(rcu_is_cpu_idle);
-
-/**
- * __rcu_is_watching - are RCU read-side critical sections safe?
- *
- * Return true if RCU is watching the running CPU, which means that
- * this CPU can safely enter RCU read-side critical sections. Unlike
- * rcu_is_cpu_idle(), the caller of __rcu_is_watching() must have at
- * least disabled preemption.
- */
-bool __rcu_is_watching(void)
-{
- return !!(atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1);
-}
+EXPORT_SYMBOL_GPL(rcu_is_watching);
#if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU)
@@ -2268,7 +2268,7 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
* If called from an extended quiescent state, invoke the RCU
* core in order to force a re-evaluation of RCU's idleness.
*/
- if (rcu_is_cpu_idle() && cpu_online(smp_processor_id()))
+ if (!rcu_is_watching() && cpu_online(smp_processor_id()))
invoke_rcu_core();
/* If interrupts were disabled or CPU offline, don't invoke RCU core. */
--
1.8.1.5
--
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