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Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 16ea67925015..35380019f0fc 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1451,9 +1451,9 @@ static int rcu_gp_init(struct rcu_state *rsp)
rnp->grphi, rnp->qsmask);
raw_spin_unlock_irq(&rnp->lock);
#ifdef CONFIG_PROVE_RCU_DELAY
- if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 &&
+ if ((prandom_u32() % (rcu_num_nodes + 1)) == 0 &&
system_state == SYSTEM_RUNNING)
- schedule_timeout_uninterruptible(2);
+ udelay(200);
#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
cond_resched();
}
@@ -1613,6 +1613,14 @@ static int __noreturn rcu_gp_kthread(void *arg)
}
}
+static void rsp_wakeup(struct irq_work *work)
+{
+ struct rcu_state *rsp = container_of(work, struct rcu_state, wakeup_work);
+
+ /* Wake up rcu_gp_kthread() to start the grace period. */
+ wake_up(&rsp->gp_wq);
+}
+
/*
* Start a new RCU grace period if warranted, re-initializing the hierarchy
* in preparation for detecting the next grace period. The caller must hold
@@ -1637,8 +1645,12 @@ rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp,
}
rsp->gp_flags = RCU_GP_FLAG_INIT;
- /* Wake up rcu_gp_kthread() to start the grace period. */
- wake_up(&rsp->gp_wq);
+ /*
+ * We can't do wakeups while holding the rnp->lock, as that
+ * could cause possible deadlocks with the rq->lock. Deter
+ * the wakeup to interrupt context.
+ */
+ irq_work_queue(&rsp->wakeup_work);
}
/*
@@ -3235,6 +3247,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
rsp->rda = rda;
init_waitqueue_head(&rsp->gp_wq);
+ init_irq_work(&rsp->wakeup_work, rsp_wakeup);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
while (i > rnp->grphi)