From: compudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Date: Thu, 21 Dec 2006 19:53:03 +0000 (+0000)
Subject: test kernel tsc
X-Git-Tag: v0.12.20~1167
X-Git-Url: https://git.lttng.org/?a=commitdiff_plain;h=41a0bd4f9ebae32d371d2d69f194e4dab4f60f0f;p=lttv.git

test kernel tsc

git-svn-id: http://ltt.polymtl.ca/svn@2322 04897980-b3bd-0310-b5e0-8ef037075253
---

diff --git a/tests/kernel/rdtsc-smp.c b/tests/kernel/rdtsc-smp.c
new file mode 100644
index 00000000..62e19a1e
--- /dev/null
+++ b/tests/kernel/rdtsc-smp.c
@@ -0,0 +1,72 @@
+/* rdtsc-smp
+ *
+ * Test TSC
+ */
+
+
+#include <linux/jiffies.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/workqueue.h>
+
+static atomic_t busy_wait;
+static struct delayed_work testwork[NR_CPUS];
+
+
+static void do_work(struct work_struct *work)
+{
+	cycles_t val;
+	int cpu1, cpu2;
+	int num_online = num_online_cpus();
+	int copybusy;
+	int i;
+
+	cpu1 = smp_processor_id();
+	printk("Busy waiting on cpu %d\n", cpu1);
+
+	/* Prime busy_wait in cache */
+	for(i=0; i<100; i++) {
+		copybusy = atomic_read(&busy_wait);
+	}
+	barrier();
+	atomic_inc(&busy_wait);
+	while(atomic_read(&busy_wait) != num_online) {
+		barrier();
+	}
+	
+	val = get_cycles();
+
+	cpu2 = smp_processor_id();
+	BUG_ON(cpu1 != cpu2);
+	printk("Cycle count on cpu %d is %llu\n", cpu1, val);
+}
+
+
+static int ltt_test_init(void)
+{
+	int cpu;
+
+	printk(KERN_ALERT "test init\n");
+	
+	atomic_set(&busy_wait, 0);
+	for_each_online_cpu(cpu) {
+		INIT_DELAYED_WORK(&testwork[cpu], do_work);
+		schedule_delayed_work_on(cpu, &testwork[cpu], 0);
+	}
+	return 0;
+}
+
+static void ltt_test_exit(void)
+{
+	/* Test program... wait for output before unload */
+	printk(KERN_ALERT "test exit\n");
+}
+
+module_init(ltt_test_init)
+module_exit(ltt_test_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Linux Trace Toolkit Test");
+