From: compudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Date: Thu, 28 May 2009 19:30:00 +0000 (+0000)
Subject: add ipi test
X-Git-Tag: v0.12.20~91
X-Git-Url: http://git.liburcu.org/?a=commitdiff_plain;h=67708ee530e10dc299f90495ac2dc3e61c5bf478;p=lttv.git

add ipi test

git-svn-id: http://ltt.polymtl.ca/svn@3398 04897980-b3bd-0310-b5e0-8ef037075253
---

diff --git a/trunk/tests/kernel/Makefile b/trunk/tests/kernel/Makefile
index adcc35c5..24cd9a11 100644
--- a/trunk/tests/kernel/Makefile
+++ b/trunk/tests/kernel/Makefile
@@ -25,6 +25,7 @@ endif
 	#obj-m += test-prefix-speed.o
 	#obj-m += test-psrwlock.o
 	obj-m += test-cmpxchg-nolock2.o
+	obj-m += test-ipi.o
 #	obj-m += test-trace-speed.o
 	obj-m += test-read-lock-speed.o
 #	obj-m += test-fct-speed.o
diff --git a/trunk/tests/kernel/test-ipi.c b/trunk/tests/kernel/test-ipi.c
new file mode 100644
index 00000000..6f3f4fb5
--- /dev/null
+++ b/trunk/tests/kernel/test-ipi.c
@@ -0,0 +1,135 @@
+/*
+ * test-ipi.c
+ *
+ * Copyright 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Distributed under GPLv2
+ */
+
+#include <linux/jiffies.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/math64.h>
+#include <linux/spinlock.h>
+#include <linux/seqlock.h>
+#include <linux/cpumask.h>
+#include <linux/smp.h>
+#include <asm/timex.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_ARM
+#include <linux/trace-clock.h>
+#define get_timestamp	trace_clock_read64
+#else
+#define get_timestamp	get_cycles
+#endif
+
+#define NR_LOOPS 20000
+
+int test_val;
+
+static void do_testbaseline(void)
+{
+	unsigned long flags;
+	unsigned int i;
+	cycles_t time1, time2, time;
+	u32 rem;
+
+	local_irq_save(flags);
+	preempt_disable();
+	time1 = get_timestamp();
+	for (i = 0; i < NR_LOOPS; i++) {
+		asm volatile ("");
+	}
+	time2 = get_timestamp();
+	local_irq_restore(flags);
+	preempt_enable();
+	time = time2 - time1;
+
+	printk(KERN_ALERT "test results: time for baseline\n");
+	printk(KERN_ALERT "number of loops: %d\n", NR_LOOPS);
+	printk(KERN_ALERT "total time: %llu\n", (unsigned long long)time);
+	time = div_u64_rem(time, NR_LOOPS, &rem);
+	printk(KERN_ALERT "-> baseline takes %llu cycles\n", (unsigned long long)time);
+	printk(KERN_ALERT "test end\n");
+}
+
+static void remote_wmb(void *info)
+{
+	smp_wmb();
+}
+
+static void do_test_ipi(void)
+{
+	unsigned int i;
+	int cpu;
+	cycles_t time1, time2, time;
+	u32 rem;
+
+	preempt_disable();
+	cpu = smp_processor_id();
+	if (cpu == 0)
+		cpu = 1;
+	else
+		cpu = 0;
+	time1 = get_timestamp();
+	for (i = 0; i < NR_LOOPS; i++) {
+		smp_call_function_single(cpu, remote_wmb, NULL, 1);
+	}
+	time2 = get_timestamp();
+	preempt_enable();
+	time = time2 - time1;
+
+	printk(KERN_ALERT "test results: time for ipi\n");
+	printk(KERN_ALERT "number of loops: %d\n", NR_LOOPS);
+	printk(KERN_ALERT "total time: %llu\n", (unsigned long long)time);
+	time = div_u64_rem(time, NR_LOOPS, &rem);
+	printk(KERN_ALERT "-> ipi takes %llu cycles\n", (unsigned long long)time);
+	printk(KERN_ALERT "test end\n");
+}
+
+static void do_test_wmb(void)
+{
+	unsigned int i;
+	cycles_t time1, time2, time;
+	u32 rem;
+
+	preempt_disable();
+	time1 = get_timestamp();
+	for (i = 0; i < NR_LOOPS; i++) {
+		wmb();
+	}
+	time2 = get_timestamp();
+	preempt_enable();
+	time = time2 - time1;
+
+	printk(KERN_ALERT "test results: time for ipi\n");
+	printk(KERN_ALERT "number of loops: %d\n", NR_LOOPS);
+	printk(KERN_ALERT "total time: %llu\n", (unsigned long long)time);
+	time = div_u64_rem(time, NR_LOOPS, &rem);
+	printk(KERN_ALERT "-> ipi takes %llu cycles\n", (unsigned long long)time);
+	printk(KERN_ALERT "test end\n");
+}
+
+static int ltt_test_init(void)
+{
+	printk(KERN_ALERT "test init\n");
+	
+	printk(KERN_ALERT "Number of active CPUs : %d\n", num_online_cpus());
+	do_testbaseline();
+	do_test_ipi();
+	do_test_wmb();
+	return -EAGAIN; /* Fail will directly unload the module */
+}
+
+static void ltt_test_exit(void)
+{
+	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("Test read lock speed");