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Diffstat (limited to 'kernel/rcu/tree.c')
-rw-r--r--kernel/rcu/tree.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e8fff14..1df100c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -103,6 +103,7 @@ struct rcu_state sname##_state = { \
.name = RCU_STATE_NAME(sname), \
.abbr = sabbr, \
.exp_mutex = __MUTEX_INITIALIZER(sname##_state.exp_mutex), \
+ .exp_wake_mutex = __MUTEX_INITIALIZER(sname##_state.exp_wake_mutex), \
}
RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
@@ -3637,7 +3638,7 @@ static bool exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
trace_rcu_exp_funnel_lock(rsp->name, rnp->level,
rnp->grplo, rnp->grphi,
TPS("wait"));
- wait_event(rnp->exp_wq[(s >> 1) & 0x1],
+ wait_event(rnp->exp_wq[(s >> 1) & 0x3],
sync_exp_work_done(rsp,
&rdp->exp_workdone2, s));
return true;
@@ -3857,6 +3858,14 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
synchronize_sched_expedited_wait(rsp);
rcu_exp_gp_seq_end(rsp);
trace_rcu_exp_grace_period(rsp->name, s, TPS("end"));
+
+ /*
+ * Switch over to wakeup mode, allowing the next GP, but -only- the
+ * 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)) {
spin_lock(&rnp->exp_lock);
@@ -3865,10 +3874,10 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
rnp->exp_seq_rq = s;
spin_unlock(&rnp->exp_lock);
}
- wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x1]);
+ wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x3]);
}
trace_rcu_exp_grace_period(rsp->name, s, TPS("endwake"));
- mutex_unlock(&rsp->exp_mutex);
+ mutex_unlock(&rsp->exp_wake_mutex);
}
/**
@@ -4530,6 +4539,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
rcu_init_one_nocb(rnp);
init_waitqueue_head(&rnp->exp_wq[0]);
init_waitqueue_head(&rnp->exp_wq[1]);
+ init_waitqueue_head(&rnp->exp_wq[2]);
+ init_waitqueue_head(&rnp->exp_wq[3]);
spin_lock_init(&rnp->exp_lock);
}
}