From 7941dbdebe2a1fda31aefa033794510f95720a5a Mon Sep 17 00:00:00 2001
From: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Date: Mon, 17 Mar 2014 18:33:28 +0200
Subject: [PATCH] rcu: Add event tracing to dyntick_save_progress_counter().
This patch adds event tracing to dyntick_save_progress_counter() in the case
where it returns 1. I used the tracepoint string "dti" because this function
returns 1 in case the CPU is in dynticks idle mode.
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---
kernel/rcu/tree.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index fca911b6b29c..c6fd0f15425c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -772,7 +772,12 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp,
{
rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
rcu_sysidle_check_cpu(rdp, isidle, maxj);
- return (rdp->dynticks_snap & 0x1) == 0;
+ if ((rdp->dynticks_snap & 0x1) == 0) {
+ trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
+ return 1;
+ } else {
+ return 0;
+ }
}
/*
--
2.34.1