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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/samples/trace_events/trace-events-sample.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/samples/trace_events/trace-events-sample.c')
-rw-r--r--kernel/samples/trace_events/trace-events-sample.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/kernel/samples/trace_events/trace-events-sample.c b/kernel/samples/trace_events/trace-events-sample.c
new file mode 100644
index 000000000..880a7d1d2
--- /dev/null
+++ b/kernel/samples/trace_events/trace-events-sample.c
@@ -0,0 +1,130 @@
+#include <linux/module.h>
+#include <linux/kthread.h>
+
+/*
+ * Any file that uses trace points, must include the header.
+ * But only one file, must include the header by defining
+ * CREATE_TRACE_POINTS first. This will make the C code that
+ * creates the handles for the trace points.
+ */
+#define CREATE_TRACE_POINTS
+#include "trace-events-sample.h"
+
+static const char *random_strings[] = {
+ "Mother Goose",
+ "Snoopy",
+ "Gandalf",
+ "Frodo",
+ "One ring to rule them all"
+};
+
+static void simple_thread_func(int cnt)
+{
+ int array[6];
+ int len = cnt % 5;
+ int i;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ);
+
+ for (i = 0; i < len; i++)
+ array[i] = i + 1;
+ array[i] = 0;
+
+ /* Silly tracepoints */
+ trace_foo_bar("hello", cnt, array, random_strings[len],
+ tsk_cpus_allowed(current));
+
+ trace_foo_with_template_simple("HELLO", cnt);
+
+ trace_foo_bar_with_cond("Some times print", cnt);
+
+ trace_foo_with_template_cond("prints other times", cnt);
+
+ trace_foo_with_template_print("I have to be different", cnt);
+}
+
+static int simple_thread(void *arg)
+{
+ int cnt = 0;
+
+ while (!kthread_should_stop())
+ simple_thread_func(cnt++);
+
+ return 0;
+}
+
+static struct task_struct *simple_tsk;
+static struct task_struct *simple_tsk_fn;
+
+static void simple_thread_func_fn(int cnt)
+{
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ);
+
+ /* More silly tracepoints */
+ trace_foo_bar_with_fn("Look at me", cnt);
+ trace_foo_with_template_fn("Look at me too", cnt);
+}
+
+static int simple_thread_fn(void *arg)
+{
+ int cnt = 0;
+
+ while (!kthread_should_stop())
+ simple_thread_func_fn(cnt++);
+
+ return 0;
+}
+
+static DEFINE_MUTEX(thread_mutex);
+
+void foo_bar_reg(void)
+{
+ pr_info("Starting thread for foo_bar_fn\n");
+ /*
+ * We shouldn't be able to start a trace when the module is
+ * unloading (there's other locks to prevent that). But
+ * for consistency sake, we still take the thread_mutex.
+ */
+ mutex_lock(&thread_mutex);
+ simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn");
+ mutex_unlock(&thread_mutex);
+}
+
+void foo_bar_unreg(void)
+{
+ pr_info("Killing thread for foo_bar_fn\n");
+ /* protect against module unloading */
+ mutex_lock(&thread_mutex);
+ if (simple_tsk_fn)
+ kthread_stop(simple_tsk_fn);
+ simple_tsk_fn = NULL;
+ mutex_unlock(&thread_mutex);
+}
+
+static int __init trace_event_init(void)
+{
+ simple_tsk = kthread_run(simple_thread, NULL, "event-sample");
+ if (IS_ERR(simple_tsk))
+ return -1;
+
+ return 0;
+}
+
+static void __exit trace_event_exit(void)
+{
+ kthread_stop(simple_tsk);
+ mutex_lock(&thread_mutex);
+ if (simple_tsk_fn)
+ kthread_stop(simple_tsk_fn);
+ simple_tsk_fn = NULL;
+ mutex_unlock(&thread_mutex);
+}
+
+module_init(trace_event_init);
+module_exit(trace_event_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("trace-events-sample");
+MODULE_LICENSE("GPL");