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Diffstat (limited to 'kernel/rcu/tree_exp.h')
-rw-r--r--kernel/rcu/tree_exp.h48
1 files changed, 42 insertions, 6 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 1549f45..97f5ffe 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -500,7 +500,6 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
* next GP, to proceed.
*/
mutex_lock(&rsp->exp_wake_mutex);
- mutex_unlock(&rsp->exp_mutex);
rcu_for_each_node_breadth_first(rsp, rnp) {
if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) {
@@ -516,6 +515,29 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
mutex_unlock(&rsp->exp_wake_mutex);
}
+/* Let the workqueue handler know what it is supposed to do. */
+struct rcu_exp_work {
+ smp_call_func_t rew_func;
+ struct rcu_state *rew_rsp;
+ unsigned long rew_s;
+ struct work_struct rew_work;
+};
+
+/*
+ * Work-queue handler to drive an expedited grace period forward.
+ */
+static void wait_rcu_exp_gp(struct work_struct *wp)
+{
+ struct rcu_exp_work *rewp;
+
+ /* Initialize the rcu_node tree in preparation for the wait. */
+ rewp = container_of(wp, struct rcu_exp_work, rew_work);
+ sync_rcu_exp_select_cpus(rewp->rew_rsp, rewp->rew_func);
+
+ /* Wait and clean up, including waking everyone. */
+ rcu_exp_wait_wake(rewp->rew_rsp, rewp->rew_s);
+}
+
/*
* Given an rcu_state pointer and a smp_call_function() handler, kick
* off the specified flavor of expedited grace period.
@@ -523,6 +545,9 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
static void _synchronize_rcu_expedited(struct rcu_state *rsp,
smp_call_func_t func)
{
+ struct rcu_data *rdp;
+ struct rcu_exp_work rew;
+ struct rcu_node *rnp;
unsigned long s;
/* If expedited grace periods are prohibited, fall back to normal. */
@@ -536,11 +561,22 @@ static void _synchronize_rcu_expedited(struct rcu_state *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);
+ /* Marshall arguments and schedule the expedited grace period. */
+ rew.rew_func = func;
+ rew.rew_rsp = rsp;
+ rew.rew_s = s;
+ INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp);
+ schedule_work(&rew.rew_work);
+
+ /* Wait for expedited grace period to complete. */
+ rdp = per_cpu_ptr(rsp->rda, raw_smp_processor_id());
+ rnp = rcu_get_root(rsp);
+ wait_event(rnp->exp_wq[(s >> 1) & 0x3],
+ sync_exp_work_done(rsp,
+ &rdp->exp_workdone0, s));
+
+ /* Let the next expedited grace period start. */
+ mutex_unlock(&rsp->exp_mutex);
}
/**