[PATCH 04/13] HW-latency: Differentiate three modes to use CPU carry out testing

[Luming Yu]

0: all online cpus
1: any one of online cpus
2: all online cpus sequentially run test

Signed-off-by: Luming Yu <luming...@intel.com>
---
 drivers/misc/hw_latency_test.c | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/hw_latency_test.c b/drivers/misc/hw_latency_test.c
index 8a8c6ba..4303644 100644
--- a/drivers/misc/hw_latency_test.c
+++ b/drivers/misc/hw_latency_test.c
@@ -47,6 +47,7 @@ static unsigned long buf_size = 262144UL;
 static struct task_struct *kthread;
 
 struct sample {
+       unsigned int cpu;
        u64     seqnum;
        u64     duration;
        struct timespec timestamp;
@@ -70,6 +71,7 @@ static struct data {
 static ktime_t now;
 struct sample_function {
        const char *name;
+       u8      type; /* 0=all parallel, 1=anyone, 2=all sequential*/
        struct list_head list;
        int (*get_sample)(void *unused);
 };
@@ -186,14 +188,11 @@ static int get_freq_sample(void *unused)
        u32     sample = 0;
        int     ret = 1;
        unsigned int cpu_tsc_freq;
-       static DEFINE_MUTEX(freq_pit_mutex);
 
        start = ktime_get();
        do {
                t1 = ktime_get();
-               mutex_lock(&freq_pit_mutex);
                cpu_tsc_freq = x86_platform.calibrate_tsc();
-               mutex_unlock(&freq_pit_mutex);
                t2 = ktime_get();
                total = ktime_to_us(ktime_sub(t2, start));
                diff = abs(cpu_tsc_freq - tsc_khz);
@@ -249,23 +248,30 @@ out:
 
 struct sample_function tsc_sample = {
        .name           = "tsc",
+       .type           = 0,
        .get_sample     = get_tsc_sample,
 };
 
 struct sample_function tsc_freq_sample = {
        .name           = "freq",
+       .type           = 2,
        .get_sample     = get_freq_sample,
 };
 
 struct sample_function random_bytes_sample = {
        .name           = "random_bytes",
+       .type           = 0,
        .get_sample     = get_random_bytes_sample,
 };
 
+static DECLARE_BITMAP(testing_cpu_map, NR_CPUS);
+
 static int kthread_fn(void *unused)
 {
        int err = 0;
        u64 interval = 0;
+       int cpu;
+       struct cpumask *testing_cpu_mask = to_cpumask(testing_cpu_map);
        int (*get_sample)(void *unused);
        
        mutex_lock(&sample_function_mutex);
@@ -274,10 +280,31 @@ static int kthread_fn(void *unused)
        else
                goto out;
 
+       cpumask_or(testing_cpu_mask, testing_cpu_mask, cpu_online_mask);
        while (!kthread_should_stop()) {
                mutex_lock(&data.lock);
-       
-               err = stop_machine(get_sample, unused, cpu_online_mask);
+
+               switch (current_sample_func->type) {
+               case 0:
+                       err = stop_machine(get_sample, unused, 
testing_cpu_mask);
+                       break;
+               case 1:
+                       err = stop_machine(get_sample, unused, NULL);
+                       break;
+               case 2:
+                       for_each_cpu(cpu, cpu_online_mask) {
+                               cpumask_clear(testing_cpu_mask);
+                               cpumask_set_cpu(cpu, testing_cpu_mask);
+                               err = stop_machine(get_sample, unused, NULL);
+                               if (err)
+                                       break;
+                       }
+                       break;
+               default:
+                       mutex_unlock(&data.lock);
+                       goto err_out;
+               }
+
                if (err) {
                        mutex_unlock(&data.lock);
                        goto err_out;
-- 
1.7.12.1

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