It's simple memory latency test without any consideration of memory
hierarchy and memory model. It just does simply scan byte by byte.
Signed-off-by: Luming Yu <luming...@intel.com>
---
drivers/misc/hw_latency_test.c | 53 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/hw_latency_test.c b/drivers/misc/hw_latency_test.c
index 78436da..f47b911 100644
--- a/drivers/misc/hw_latency_test.c
+++ b/drivers/misc/hw_latency_test.c
@@ -46,11 +46,15 @@ static DEFINE_MUTEX(ring_buffer_mutex);
static unsigned long buf_size = 262144UL;
static struct task_struct *kthread;
+static u8 *__start = (u8 *)0xffff880000000000;
+static u8 *__end = (u8 *)0xffffc7ffffffffff;
+
struct sample {
unsigned int cpu;
u64 seqnum;
u64 duration;
struct timespec timestamp;
+ u64 addr;
unsigned long lost;
};
@@ -134,6 +138,7 @@ static int buffer_add_sample(u64 sample)
s.seqnum = data.count;
s.duration = sample;
s.timestamp = CURRENT_TIME;
+ s.addr = (u64) __start;
ret = __buffer_add_sample(&s);
if (sample > data.max_sample)
@@ -247,6 +252,42 @@ out:
return ret;
}
+static int get_mem_sample(void *unused)
+{
+ ktime_t start, t1, t2;
+ s64 diff, total = 0;
+ u64 sample = 0;
+ int ret = 1;
+ u8 temp;
+
+ now = start = ktime_get();
+ do {
+ t1 = now;
+ now = t2 = ktime_get();
+
+ total = ktime_to_ns(ktime_sub(t2, start));
+ temp = *__start++;
+ diff = ktime_to_ns(ktime_sub(t2, t1));
+
+ if (diff < 0) {
+ printk(KERN_ERR BANNER "time running backwards\n");
+ goto out;
+ }
+
+ if (diff > sample)
+ sample = diff;
+
+ if (__start == __end) {
+ __start = (u8 *)0xffff880000000000;
+ printk(KERN_INFO BANNER "one pass finished, jmp to the
beginning\n");
+ }
+
+ } while (total <= data.sample_width);
+
+ ret = buffer_add_sample(sample);
+out:
+ return ret;
+}
struct sample_function tsc_sample = {
.name = "tsc",
@@ -266,6 +307,12 @@ struct sample_function random_bytes_sample = {
.get_sample = get_random_bytes_sample,
};
+struct sample_function mem_sample = {
+ .name = "mem",
+ .type = 1,
+ .get_sample = get_mem_sample,
+};
+
static DECLARE_BITMAP(testing_cpu_map, NR_CPUS);
static int kthread_fn(void *unused)
@@ -617,11 +664,12 @@ static ssize_t debug_sample_fread(struct file *filp, char
__user *ubuf,
goto out;
}
}
- len = snprintf(buf, sizeof(buf), "[%d]%010lu.%010lu\t%llu\n",
+ len = snprintf(buf, sizeof(buf), "[%d]%010lu.%010lu\t%llu\t[%llx]\n",
sample->cpu,
sample->timestamp.tv_sec,
sample->timestamp.tv_nsec,
- sample->duration);
+ sample->duration,
+ sample->addr);
if (len > cnt)
goto out;
if (copy_to_user(ubuf, buf,len))
@@ -827,6 +875,7 @@ static int hw_test_init(void)
sample_function_register(&tsc_sample);
sample_function_register(&tsc_freq_sample);
sample_function_register(&random_bytes_sample);
+ sample_function_register(&mem_sample);
ret = init_stats();
if (0 != ret)
--
1.7.12.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
