rcu: Clean up flavor-related definitions and comments in tree_exp.h

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2018-07-07 18:12:26 -07:00
parent 49918a54e6
commit 8fa946d428

View File

@ -601,8 +601,8 @@ static void wait_rcu_exp_gp(struct work_struct *wp)
}
/*
* Given an rcu_state pointer and a smp_call_function() handler, kick
* off the specified flavor of expedited grace period.
* Given a smp_call_function() handler, kick off the specified
* implementation of expedited grace period.
*/
static void _synchronize_rcu_expedited(smp_call_func_t func)
{
@ -721,7 +721,7 @@ static void sync_rcu_exp_handler(void *unused)
resched_cpu(rdp->cpu);
}
/* PREEMPT=y, so no RCU-sched to clean up after. */
/* PREEMPT=y, so no PREEMPT=n expedited grace period to clean up after. */
static void sync_sched_exp_online_cleanup(int cpu)
{
}
@ -798,13 +798,13 @@ static void sync_sched_exp_online_cleanup(int cpu)
}
/*
* Because a context switch is a grace period for RCU-sched, any blocking
* grace-period wait automatically implies a grace period if there
* is only one CPU online at any point time during execution of either
* synchronize_sched() or synchronize_rcu_bh(). It is OK to occasionally
* incorrectly indicate that there are multiple CPUs online when there
* was in fact only one the whole time, as this just adds some overhead:
* RCU still operates correctly.
* Because a context switch is a grace period for !PREEMPT, any
* blocking grace-period wait automatically implies a grace period if
* there is only one CPU online at any point time during execution of
* either synchronize_rcu() or synchronize_rcu_expedited(). It is OK to
* occasionally incorrectly indicate that there are multiple CPUs online
* when there was in fact only one the whole time, as this just adds some
* overhead: RCU still operates correctly.
*/
static int rcu_blocking_is_gp(void)
{
@ -823,7 +823,7 @@ void synchronize_rcu_expedited(void)
RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) ||
lock_is_held(&rcu_lock_map) ||
lock_is_held(&rcu_sched_lock_map),
"Illegal synchronize_sched_expedited() in RCU read-side critical section");
"Illegal synchronize_rcu_expedited() in RCU read-side critical section");
/* If only one CPU, this is automatically a grace period. */
if (rcu_blocking_is_gp())