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authorPaul E. McKenney <paul.mckenney@linaro.org>2011-04-03 21:33:51 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-05-05 23:16:56 -0700
commit4a29865689dbb87a02e3b0fff4a4ae5041273173 (patch)
tree72c9f1641a9fb05e3ae4d8cc068f62f9c566bae9 /kernel/rcutree.c
parentd71df90eadfc35aa549ff9a850842673febca71f (diff)
downloadlinux-4a29865689dbb87a02e3b0fff4a4ae5041273173.tar.bz2
rcu: make rcutorture version numbers available through debugfs
It is not possible to accurately correlate rcutorture output with that of debugfs. This patch therefore adds a debugfs file that prints out the rcutorture version number, permitting easy correlation. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index d8917401cbbc..bb84deca3319 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -102,6 +102,18 @@ static void invoke_rcu_cpu_kthread(void);
#define RCU_KTHREAD_PRIO 1 /* RT priority for per-CPU kthreads. */
/*
+ * Track the rcutorture test sequence number and the update version
+ * number within a given test. The rcutorture_testseq is incremented
+ * on every rcutorture module load and unload, so has an odd value
+ * when a test is running. The rcutorture_vernum is set to zero
+ * when rcutorture starts and is incremented on each rcutorture update.
+ * These variables enable correlating rcutorture output with the
+ * RCU tracing information.
+ */
+unsigned long rcutorture_testseq;
+unsigned long rcutorture_vernum;
+
+/*
* Return true if an RCU grace period is in progress. The ACCESS_ONCE()s
* permit this function to be invoked without holding the root rcu_node
* structure's ->lock, but of course results can be subject to change.
@@ -193,6 +205,31 @@ void rcu_bh_force_quiescent_state(void)
EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
/*
+ * Record the number of times rcutorture tests have been initiated and
+ * terminated. This information allows the debugfs tracing stats to be
+ * correlated to the rcutorture messages, even when the rcutorture module
+ * is being repeatedly loaded and unloaded. In other words, we cannot
+ * store this state in rcutorture itself.
+ */
+void rcutorture_record_test_transition(void)
+{
+ rcutorture_testseq++;
+ rcutorture_vernum = 0;
+}
+EXPORT_SYMBOL_GPL(rcutorture_record_test_transition);
+
+/*
+ * Record the number of writer passes through the current rcutorture test.
+ * This is also used to correlate debugfs tracing stats with the rcutorture
+ * messages.
+ */
+void rcutorture_record_progress(unsigned long vernum)
+{
+ rcutorture_vernum++;
+}
+EXPORT_SYMBOL_GPL(rcutorture_record_progress);
+
+/*
* Force a quiescent state for RCU-sched.
*/
void rcu_sched_force_quiescent_state(void)