4 files changed, 25 insertions, 4 deletions

diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt
index efd8cc95c06b..a851118775d8 100644
--- a/Documentation/RCU/trace.txt
+++ b/Documentation/RCU/trace.txt
@@ -125,6 +125,17 @@ o	"b" is the batch limit for this CPU.  If more than this number
         of RCU callbacks is ready to invoke, then the remainder will
         be deferred.
 
+o       "ci" is the number of RCU callbacks that have been invoked for
+        this CPU.  Note that ci+ql is the number of callbacks that have
+        been registered in absence of CPU-hotplug activity.
+
+o       "co" is the number of RCU callbacks that have been orphaned due to
+        this CPU going offline.
+
+o       "ca" is the number of RCU callbacks that have been adopted due to
+        other CPUs going offline.  Note that ci+co-ca+ql is the number of
+        RCU callbacks registered on this CPU.
+
 There is also an rcu/rcudata.csv file with the same information in
 comma-separated-variable spreadsheet format.
 
@@ -180,7 +191,7 @@ o	"s" is the "signaled" state that drives force_quiescent_state()'s
 
 o       "jfq" is the number of jiffies remaining for this grace period
         before force_quiescent_state() is invoked to help push things
-        along.  Note that CPUs in dyntick-idle mode thoughout the grace
+        along.  Note that CPUs in dyntick-idle mode throughout the grace
         period will not report on their own, but rather must be check by
         some other CPU via force_quiescent_state().
 
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 42140a860bb9..e75073504a31 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1004,6 +1004,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
         for (i = 0; i < RCU_NEXT_SIZE; i++)
                 rdp->nxttail[i] = &rdp->nxtlist;
         rsp->orphan_qlen += rdp->qlen;
+        rdp->n_cbs_orphaned += rdp->qlen;
         rdp->qlen = 0;
         raw_spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */
 }
@@ -1025,6 +1026,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
         *rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
         rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_tail;
         rdp->qlen += rsp->orphan_qlen;
+        rdp->n_cbs_adopted += rsp->orphan_qlen;
         rsp->orphan_cbs_list = NULL;
         rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
         rsp->orphan_qlen = 0;
@@ -1156,6 +1158,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
 
         /* Update count, and requeue any remaining callbacks. */
         rdp->qlen -= count;
+        rdp->n_cbs_invoked += count;
         if (list != NULL) {
                 *tail = rdp->nxtlist;
                 rdp->nxtlist = list;
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 7918ba61873f..91d4170c5c13 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -202,6 +202,9 @@ struct rcu_data {
         long            qlen;           /* # of queued callbacks */
         long            qlen_last_fqs_check;
                                         /* qlen at last check for QS forcing */
+        unsigned long   n_cbs_invoked;  /* count of RCU cbs invoked. */
+        unsigned long   n_cbs_orphaned; /* RCU cbs sent to orphanage. */
+        unsigned long   n_cbs_adopted;  /* RCU cbs adopted from orphanage. */
         unsigned long   n_force_qs_snap;
                                         /* did other CPU force QS recently? */
         long            blimit;         /* Upper limit on a processed batch */
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 458e032a3a30..d15430b9d122 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -64,7 +64,9 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
                    rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
         seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
-        seq_printf(m, " ql=%ld b=%ld\n", rdp->qlen, rdp->blimit);
+        seq_printf(m, " ql=%ld b=%ld", rdp->qlen, rdp->blimit);
+        seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
+                   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
 }
 
 #define PRINT_RCU_DATA(name, func, m) \
@@ -119,7 +121,9 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
                    rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
         seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
-        seq_printf(m, ",%ld,%ld\n", rdp->qlen, rdp->blimit);
+        seq_printf(m, ",%ld,%ld", rdp->qlen, rdp->blimit);
+        seq_printf(m, ",%lu,%lu,%lu\n",
+                   rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
 }
 
 static int show_rcudata_csv(struct seq_file *m, void *unused)
@@ -128,7 +132,7 @@ static int show_rcudata_csv(struct seq_file *m, void *unused)
 #ifdef CONFIG_NO_HZ
         seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
 #endif /* #ifdef CONFIG_NO_HZ */
-        seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
+        seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
 #ifdef CONFIG_TREE_PREEMPT_RCU
         seq_puts(m, "\"rcu_preempt:\"\n");
         PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);