rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCU

For the short term, map synchronize_rcu_expedited() to
synchronize_rcu() for TREE_PREEMPT_RCU and to
synchronize_sched_expedited() for TREE_RCU.

Longer term, there needs to be a real expedited grace period for
TREE_PREEMPT_RCU, but candidate patches to date are considerably
more complex and intrusive.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: npiggin@suse.de
Cc: jens.axboe@oracle.com
LKML-Reference: <12555405592331-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Paul E. McKenney 2009-10-14 10:15:56 -07:00 committed by Ingo Molnar
parent 37c72e56f6
commit 019129d595
2 changed files with 22 additions and 5 deletions

View file

@ -76,11 +76,7 @@ static inline void __rcu_read_unlock_bh(void)
extern void call_rcu_sched(struct rcu_head *head,
void (*func)(struct rcu_head *rcu));
static inline void synchronize_rcu_expedited(void)
{
synchronize_sched_expedited();
}
extern void synchronize_rcu_expedited(void);
static inline void synchronize_rcu_bh_expedited(void)
{

View file

@ -392,6 +392,17 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
}
EXPORT_SYMBOL_GPL(call_rcu);
/*
* Wait for an rcu-preempt grace period. We are supposed to expedite the
* grace period, but this is the crude slow compatability hack, so just
* invoke synchronize_rcu().
*/
void synchronize_rcu_expedited(void)
{
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
/*
* Check to see if there is any immediate preemptable-RCU-related work
* to be done.
@ -564,6 +575,16 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
}
EXPORT_SYMBOL_GPL(call_rcu);
/*
* Wait for an rcu-preempt grace period, but make it happen quickly.
* But because preemptable RCU does not exist, map to rcu-sched.
*/
void synchronize_rcu_expedited(void)
{
synchronize_sched_expedited();
}
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
/*
* Because preemptable RCU does not exist, it never has any work to do.
*/