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-rw-r--r--kernel/rcupdate.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 30b0bba03859..ccc45d49ce71 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -429,6 +429,36 @@ static void rcu_process_callbacks(unsigned long unused)
&__get_cpu_var(rcu_bh_data));
}
+static int __rcu_pending(struct rcu_ctrlblk *rcp, struct rcu_data *rdp)
+{
+ /* This cpu has pending rcu entries and the grace period
+ * for them has completed.
+ */
+ if (rdp->curlist && !rcu_batch_before(rcp->completed, rdp->batch))
+ return 1;
+
+ /* This cpu has no pending entries, but there are new entries */
+ if (!rdp->curlist && rdp->nxtlist)
+ return 1;
+
+ /* This cpu has finished callbacks to invoke */
+ if (rdp->donelist)
+ return 1;
+
+ /* The rcu core waits for a quiescent state from the cpu */
+ if (rdp->quiescbatch != rcp->cur || rdp->qs_pending)
+ return 1;
+
+ /* nothing to do */
+ return 0;
+}
+
+int rcu_pending(int cpu)
+{
+ return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) ||
+ __rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
+}
+
void rcu_check_callbacks(int cpu, int user)
{
if (user ||