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rcu: Eliminate the unused __rcu_is_watching() function

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The __rcu_is_watching() function is currently not used, aside from
to implement the rcu_is_watching() function.  This commit therefore
eliminates __rcu_is_watching(), which has the beneficial side-effect
of shrinking include/linux/rcupdate.h a bit.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2017-05-03 11:06:05 -07:00
parent d0df7a3491
commit 791875d16e
4 changed files with 4 additions and 43 deletions
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13
kernel/rcu/tiny.c
View File

@@ -59,19 +59,6 @@ void rcu_barrier_sched(void)
}
EXPORT_SYMBOL(rcu_barrier_sched);
#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
/*
* Test whether RCU thinks that the current CPU is idle.
*/
bool notrace __rcu_is_watching(void)
{
return true;
}
EXPORT_SYMBOL(__rcu_is_watching);
#endif /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
/*
* Helper function for rcu_sched_qs() and rcu_bh_qs().
* Also irqs are disabled to avoid confusion due to interrupt handlers

19
kernel/rcu/tree.c
View File

@@ -1138,23 +1138,12 @@ void rcu_nmi_exit(void)
rcu_dynticks_eqs_enter();
}
/**
* __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 notrace __rcu_is_watching(void)
{
return !rcu_dynticks_curr_cpu_in_eqs();
}
/**
* 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
* Return true if RCU is watching the running CPU, which means that this
* CPU can safely enter RCU read-side critical sections. In other words,
* if the current CPU is in its idle loop and is neither in an interrupt
* or NMI handler, return true.
*/
bool notrace rcu_is_watching(void)
@@ -1162,7 +1151,7 @@ bool notrace rcu_is_watching(void)
bool ret;
preempt_disable_notrace();
ret = __rcu_is_watching();
ret = !rcu_dynticks_curr_cpu_in_eqs();
preempt_enable_notrace();
return ret;
}