1 files changed, 17 insertions, 9 deletions

diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
index c847e59c6006..04c728147be0 100644
--- a/include/linux/rcuclassic.h
+++ b/include/linux/rcuclassic.h
@@ -66,11 +66,7 @@ static inline int rcu_batch_after(long a, long b)
         return (a - b) > 0;
 }
 
-/*
- * Per-CPU data for Read-Copy UPdate.
- * nxtlist - new callbacks are added here
- * curlist - current batch for which quiescent cycle started if any
- */
+/* Per-CPU data for Read-Copy UPdate. */
 struct rcu_data {
         /* 1) quiescent state handling : */
         long            quiescbatch;     /* Batch # for grace period */
@@ -78,12 +74,24 @@ struct rcu_data {
         int             qs_pending;      /* core waits for quiesc state */
 
         /* 2) batch handling */
-        long            batch;           /* Batch # for current RCU batch */
+        /*
+         * if nxtlist is not NULL, then:
+         * batch:
+         *      The batch # for the last entry of nxtlist
+         * [*nxttail[1], NULL = *nxttail[2]):
+         *      Entries that batch # <= batch
+         * [*nxttail[0], *nxttail[1]):
+         *      Entries that batch # <= batch - 1
+         * [nxtlist, *nxttail[0]):
+         *      Entries that batch # <= batch - 2
+         *      The grace period for these entries has completed, and
+         *      the other grace-period-completed entries may be moved
+         *      here temporarily in rcu_process_callbacks().
+         */
+        long            batch;
         struct rcu_head *nxtlist;
-        struct rcu_head **nxttail;
+        struct rcu_head **nxttail[3];
         long            qlen;            /* # of queued callbacks */
-        struct rcu_head *curlist;
-        struct rcu_head **curtail;
         struct rcu_head *donelist;
         struct rcu_head **donetail;
         long            blimit;          /* Upper limit on a processed batch */