From: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
When a CPU is first determined to be a no-CBs CPUs, this commit causes
any early boot callbacks to be moved to the no-CBs callback list,
allowing them t obe invoked.
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 1 +
kernel/rcu/tree_plugin.h | 24 ++++++++++++------------
2 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 92fd3eab5823..0317bf7d997f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2851,6 +2851,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct
rcu_head *rcu),
* and then drop through to queue the callback.
*/
BUG_ON(cpu != -1);
+ WARN_ON_ONCE(!rcu_is_watching());
if (!likely(rdp->nxtlist))
init_default_callback_list(rdp);
}
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 75d5f096bcb0..afddd5641bea 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2393,18 +2393,8 @@ void __init rcu_init_nohz(void)
pr_info("\tPoll for callbacks from no-CBs CPUs.\n");
for_each_rcu_flavor(rsp) {
- for_each_cpu(cpu, rcu_nocb_mask) {
- struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
-
- /*
- * If there are early callbacks, they will need
- * to be moved to the nocb lists.
- */
- WARN_ON_ONCE(rdp->nxttail[RCU_NEXT_TAIL] !=
- &rdp->nxtlist &&
- rdp->nxttail[RCU_NEXT_TAIL] != NULL);
- init_nocb_callback_list(rdp);
- }
+ for_each_cpu(cpu, rcu_nocb_mask)
+ init_nocb_callback_list(per_cpu_ptr(rsp->rda, cpu));
rcu_organize_nocb_kthreads(rsp);
}
}
@@ -2541,6 +2531,16 @@ static bool init_nocb_callback_list(struct rcu_data *rdp)
if (!rcu_is_nocb_cpu(rdp->cpu))
return false;
+ /* If there are early-boot callbacks, move them to nocb lists. */
+ if (rdp->nxtlist) {
+ rdp->nocb_head = rdp->nxtlist;
+ rdp->nocb_tail = rdp->nxttail[RCU_NEXT_TAIL];
+ atomic_long_set(&rdp->nocb_q_count, rdp->qlen);
+ atomic_long_set(&rdp->nocb_q_count_lazy, rdp->qlen_lazy);
+ rdp->nxtlist = NULL;
+ rdp->qlen = 0;
+ rdp->qlen_lazy = 0;
+ }
rdp->nxttail[RCU_NEXT_TAIL] = NULL;
return true;
}
--
1.8.1.5
--
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