Commit-ID: f7b8eb847e35b18d3ec333774691a905bf16017f
Gitweb: http://git.kernel.org/tip/f7b8eb847e35b18d3ec333774691a905bf16017f
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Fri, 24 Jun 2016 11:30:32 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Mon, 22 Aug 2016 09:30:11 -0700
rcu: Consolidate expedited grace period machinery
The functions synchronize_rcu_expedited() and synchronize_sched_expedited()
have nearly identical code. This commit therefore consolidates this code
into a new _synchronize_rcu_expedited() function.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree_exp.h | 62 ++++++++++++++++++++++++---------------------------
1 file changed, 29 insertions(+), 33 deletions(-)
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 6d86ab6..1549f45 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -516,6 +516,33 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
mutex_unlock(&rsp->exp_wake_mutex);
}
+/*
+ * Given an rcu_state pointer and a smp_call_function() handler, kick
+ * off the specified flavor of expedited grace period.
+ */
+static void _synchronize_rcu_expedited(struct rcu_state *rsp,
+ smp_call_func_t func)
+{
+ unsigned long s;
+
+ /* If expedited grace periods are prohibited, fall back to normal. */
+ if (rcu_gp_is_normal()) {
+ wait_rcu_gp(rsp->call);
+ return;
+ }
+
+ /* Take a snapshot of the sequence number. */
+ s = rcu_exp_gp_seq_snap(rsp);
+ if (exp_funnel_lock(rsp, s))
+ return; /* Someone else did our work for us. */
+
+ /* Initialize the rcu_node tree in preparation for the wait. */
+ sync_rcu_exp_select_cpus(rsp, func);
+
+ /* Wait and clean up, including waking everyone. */
+ rcu_exp_wait_wake(rsp, s);
+}
+
/**
* synchronize_sched_expedited - Brute-force RCU-sched grace period
*
@@ -534,29 +561,13 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
*/
void synchronize_sched_expedited(void)
{
- unsigned long s;
struct rcu_state *rsp = &rcu_sched_state;
/* If only one CPU, this is automatically a grace period. */
if (rcu_blocking_is_gp())
return;
- /* If expedited grace periods are prohibited, fall back to normal. */
- if (rcu_gp_is_normal()) {
- wait_rcu_gp(call_rcu_sched);
- return;
- }
-
- /* Take a snapshot of the sequence number. */
- s = rcu_exp_gp_seq_snap(rsp);
- if (exp_funnel_lock(rsp, s))
- return; /* Someone else did our work for us. */
-
- /* Initialize the rcu_node tree in preparation for the wait. */
- sync_rcu_exp_select_cpus(rsp, sync_sched_exp_handler);
-
- /* Wait and clean up, including waking everyone. */
- rcu_exp_wait_wake(rsp, s);
+ _synchronize_rcu_expedited(rsp, sync_sched_exp_handler);
}
EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
@@ -620,23 +631,8 @@ static void sync_rcu_exp_handler(void *info)
void synchronize_rcu_expedited(void)
{
struct rcu_state *rsp = rcu_state_p;
- unsigned long s;
- /* If expedited grace periods are prohibited, fall back to normal. */
- if (rcu_gp_is_normal()) {
- wait_rcu_gp(call_rcu);
- return;
- }
-
- s = rcu_exp_gp_seq_snap(rsp);
- if (exp_funnel_lock(rsp, s))
- return; /* Someone else did our work for us. */
-
- /* Initialize the rcu_node tree in preparation for the wait. */
- sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler);
-
- /* Wait for ->blkd_tasks lists to drain, then wake everyone up. */
- rcu_exp_wait_wake(rsp, s);
+ _synchronize_rcu_expedited(rsp, sync_rcu_exp_handler);
}
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
--
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