tracing: Add trace_printk sample code

[sfrench/cifs-2.6.git] / samples / trace_printk / trace-printk.c

diff --git a/samples/trace_printk/trace-printk.c b/samples/trace_printk/trace-printk.c
new file mode 100644 (file)
index 0000000..e9e0040
--- /dev/null
+++ b/samples/trace_printk/trace-printk.c
@@ -0,0 +1,56 @@
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/irq_work.h>
+
+/* Must not be static to force gcc to consider these non constant */
+char *trace_printk_test_global_str =
+       "This is a dynamic string that will use trace_puts\n";
+
+char *trace_printk_test_global_str_irq =
+       "(irq) This is a dynamic string that will use trace_puts\n";
+
+char *trace_printk_test_global_str_fmt =
+       "%sThis is a %s that will use trace_printk\n";
+
+static struct irq_work irqwork;
+
+static void trace_printk_irq_work(struct irq_work *work)
+{
+       trace_printk("(irq) This is a static string that will use trace_bputs\n");
+       trace_printk(trace_printk_test_global_str_irq);
+
+       trace_printk("(irq) This is a %s that will use trace_bprintk()\n",
+                    "static string");
+
+       trace_printk(trace_printk_test_global_str_fmt,
+                    "(irq) ", "dynamic string");
+}
+
+static int __init trace_printk_init(void)
+{
+       init_irq_work(&irqwork, trace_printk_irq_work);
+
+       trace_printk("This is a static string that will use trace_bputs\n");
+       trace_printk(trace_printk_test_global_str);
+
+       /* Kick off printing in irq context */
+       irq_work_queue(&irqwork);
+
+       trace_printk("This is a %s that will use trace_bprintk()\n",
+                    "static string");
+
+       trace_printk(trace_printk_test_global_str_fmt, "", "dynamic string");
+
+       return 0;
+}
+
+static void __exit trace_printk_exit(void)
+{
+}
+
+module_init(trace_printk_init);
+module_exit(trace_printk_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("trace-printk");
+MODULE_LICENSE("GPL");