rcu: Trace callback acceleration

This commit adds event tracing for callback acceleration to allow better
tracking of callbacks through the system.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index ac6a75d152ef..e9dce4fa76d8 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1168,6 +1168,12 @@ static void rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp,
                 rdp->nxttail[i] = rdp->nxttail[RCU_NEXT_TAIL];
                 rdp->nxtcompleted[i] = c;
         }
+
+        /* Trace depending on how much we were able to accelerate. */
+        if (!*rdp->nxttail[RCU_WAIT_TAIL])
+                trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccWaitCB");
+        else
+                trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccReadyCB");
 }
 
 /*