From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Tue, 17 Sep 2013 11:43:21 +0000 (+0200)
Subject: Add vcanbench tool
X-Git-Tag: fix-allnoconfig~131
X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-benchmark.git/commitdiff_plain/5bcd0741bde353a1b8d920116f2c3cd116b9295c

Add vcanbench tool

I forgot to commit this tool when I created it yeas ago. If I remember well
it can be used to measure performance of vcan interfaces.
---

diff --git a/latester/Makefile.omk b/latester/Makefile.omk
index 0d1e2be..63db1c2 100644
--- a/latester/Makefile.omk
+++ b/latester/Makefile.omk
@@ -1,9 +1,12 @@
 # -*- makefile -*-
 
-bin_PROGRAMS += latester
+bin_PROGRAMS += latester vcanbench
 latester_SOURCES = latester.c
 latester_LIBS = rt pthread m talloc popt #ulut
 
+vcanbench_SOURCES = vcanbench.c
+vcanbench_LIBS = rt m talloc
+
 INCLUDES = -DSO_RXQ_OVFL=40 \
 	   -DPF_CAN=29 \
 	   -DAF_CAN=PF_CAN
diff --git a/latester/vcanbench.c b/latester/vcanbench.c
new file mode 100644
index 0000000..9aab186
--- /dev/null
+++ b/latester/vcanbench.c
@@ -0,0 +1,137 @@
+/*******************************************************/
+/* Simple vcan latency benchmark		       */
+/* Copyright (C) 2012 Michal Sojka, DCE FEE CTU Prague */
+/* License: GPLv2				       */
+/*******************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <linux/can.h>
+#include <linux/can/raw.h>
+#include <net/if.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <time.h>
+
+#define MEMSET_ZERO(obj) memset(&(obj), 0, sizeof(obj))
+
+static inline int sock_get_if_index(int s, const char *if_name)
+{
+	struct ifreq ifr;
+	MEMSET_ZERO(ifr);
+
+	strcpy(ifr.ifr_name, if_name);
+	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
+		error(1, errno, "SIOCGIFINDEX '%s'", if_name);
+	return ifr.ifr_ifindex;
+}
+
+int create_can_socket(const char *dev)
+{
+	int s;
+	struct sockaddr_can addr;
+	if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
+		error(1, errno, "socket");
+
+	addr.can_family = AF_CAN;
+	addr.can_ifindex = sock_get_if_index(s, dev);
+
+	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
+		error(1, errno, "bind");
+
+	return s;
+}
+
+/* Subtract the `struct timespec' values X and Y, storing the result in
+   RESULT.  Return 1 if the difference is negative, otherwise 0.  */
+
+int timespec_subtract (struct timespec *result, const struct timespec *x, const struct timespec *yy)
+{
+	struct timespec ylocal = *yy, *y = &ylocal;
+	/* Perform the carry for the later subtraction by updating Y. */
+	if (x->tv_nsec < y->tv_nsec) {
+		int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
+		y->tv_nsec -= 1000000000 * nsec;
+		y->tv_sec += nsec;
+	}
+	if (x->tv_nsec - y->tv_nsec > 1000000000) {
+		int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
+		y->tv_nsec += 1000000000 * nsec;
+		y->tv_sec -= nsec;
+	}
+
+	/* Compute the time remaining to wait.
+	   `tv_nsec' is certainly positive. */
+	result->tv_sec = x->tv_sec - y->tv_sec;
+	result->tv_nsec = x->tv_nsec - y->tv_nsec;
+
+	/* Return 1 if result is negative. */
+	return x->tv_sec < y->tv_sec;
+}
+
+unsigned long timespec_diff_ns(const struct timespec *x, const struct timespec *y)
+{
+	struct timespec r;
+	timespec_subtract(&r, x, y);
+	return r.tv_sec*1000000000 + r.tv_nsec;
+}
+
+#define CHKERR(expr) ({ int __ret = (expr); if (__ret == -1) error(1, errno, #expr); __ret; })
+
+static int cmp(const void *p1, const void *p2)
+{
+	return *(unsigned long*)p1 - *(unsigned long*)p2;
+}
+
+int main(int argc, char *argv[])
+{
+	const char *dev;
+	long count;
+	int s1, s2;
+
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s <dev> [ <frame_count> ]\n", argv[0]);
+		exit(1);
+	}
+	dev = argv[1];
+	count = argc > 2 ? atol(argv[2]) : -1;
+
+	CHKERR(s1 = create_can_socket(dev));
+	CHKERR(s2 = create_can_socket(dev));
+
+	unsigned long *ns = NULL;
+
+	if (count > 0)
+		ns = malloc(count*sizeof(*ns));
+
+	unsigned long i;
+	for (i = 0; count == -1 || i < count; i++) {
+		struct can_frame f1 = { .can_id = 0x123, .can_dlc = 8 }, f2;
+		struct timespec t1, t2;
+
+		clock_gettime(CLOCK_MONOTONIC, &t1);
+		CHKERR(write(s1, &f1, sizeof(f1)));
+		CHKERR(read(s2, &f2, sizeof(f2)));
+		clock_gettime(CLOCK_MONOTONIC, &t2);
+		unsigned long delay = timespec_diff_ns(&t2, &t1);
+		if (count >= 0) {
+			ns[i] = delay;
+		} else
+			printf("delay %lu ns\n", delay);
+	}
+
+	if (ns) {
+		unsigned long long sum = 0;
+		for (i = 0; i < count; i++)
+			sum += ns[i];
+		printf("avg=%lld [ns]\n", sum/count);
+
+		qsort(ns, count, sizeof(*ns), cmp);
+		printf("percentiles: 0th:%ld 25th:%d 50th:%d 75th:%d 100th:%d\n",
+		       ns[0], ns[count/4], ns[count/2], ns[count*3/4], ns[count-1]);
+	}
+
+	return 0;
+}