linux-kernel - [PATCH 08/13] HW-latency: A stupid memory scanner for raw memory latency test

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1352080784-30839-9-git-send-email-luming.yu@gmail.com>
Date:	Sun,  4 Nov 2012 20:59:39 -0500
From:	Luming Yu <luming.yu@...il.com>
To:	arnd@...db.de, linux-kernel@...r.kernel.org
Cc:	Luming Yu <luming.yu@...il.com>, Luming Yu <luming.yu@...el.com>
Subject: [PATCH 08/13] HW-latency: A stupid memory scanner for raw memory latency test

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.yu@...el.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 majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/