Hello,
I want to test the fasted transmit speed of my socketcan.
Attached my simple test.
I want to write message by message to socketcan without a break.
I expect an error return value, if I cannot write, because the queue is
full.
I count only correct written values.
On my system only 9772 messages from 10000 are transmitted. On a
different customer system only around 2700 messages are transmitted.
Can you please check, if I have a mistake in my test program?
Do you have an other idea?
I test on a classical CAN bus with a bitrate of 250kbit/s.
The analyzer on a second device and also a test with a local candump
also connected to can0, show the same values.
Which information are required?
Which part of the socketcan software is related to this problem?
$ uname -a
Linux **** 4.15.0-36-generic #39-Ubuntu SMP Mon Sep 24 16:19:09 UTC 2018
x86_64 x86_64 x86_64 GNU/Linux
after some test:
$ ip -details -statistics link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc fq_codel state UNKNOWN
mode DEFAULT group default qlen 10000
link/can promiscuity 0
can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
bitrate 250000 sample-point 0.875
tq 25 prop-seg 69 phase-seg1 70 phase-seg2 20 sjw 1
pcan_usb_fd: tseg1 1..256 tseg2 1..128 sjw 1..128 brp 1..1024
brp-inc 1
pcan_usb_fd: dtseg1 1..32 dtseg2 1..16 dsjw 1..16 dbrp 1..1024
dbrp-inc 1
clock 80000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 0 0 0 0 0
numtxqueues 1 numrxqueues 1 gso_max_size 65536
gso_max_segs 65535
RX: bytes packets errors dropped overrun mcast
895568 393815 0 0 0 0
TX: bytes packets errors dropped carrier collsns
32413275 8959110 0 0 0 0
5: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc fq_codel state UNKNOWN
mode DEFAULT group default qlen 10000
link/can promiscuity 0
can state ERROR-ACTIVE restart-ms 100
bitrate 250000 sample-point 0.875
tq 250 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
kvaser_usb: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
clock 8000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
1 0 0 0 0 0
numtxqueues 1 numrxqueues 1 gso_max_size 65536
gso_max_segs 65535
RX: bytes packets errors dropped overrun mcast
8 1 0 0 0 0
TX: bytes packets errors dropped carrier collsns
117096 39032 0 0 0 0
My system is a desktop with a peak usb interface , second test with
kvaser usb. The value of qlen seams
to be irrelevant for this test. I also don't get a full error on
qlen=10. Never.
Our customer use an embedded Linux with a PIC express card, completely
other than my system.
I'm sorry, I don't have more detail information.
My question is related to my testprogram attached to this mail.
Thank you
Steffen
/* header of standard C - libraries
---------------------------------------------------------------------------*/
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
/* OS headers
---------------------------------------------------------------------------*/
#include <net/if.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/can.h>
#include <linux/can/raw.h>
#include <linux/can/error.h>
#define CAN_INTERFACE "can0"
const char * interface_cstr = CAN_INTERFACE;
static int mBSDSocket; /*!< handle of BSD socket */
struct ifreq ifr;
struct sockaddr_can addr;
struct can_frame frame;
int main(int par)
{
int i; /*! loop counter */
ssize_t nbytes;
printf("frame size: %ld\n", sizeof(frame));
/* create RAW socket for CAN */
mBSDSocket = socket(PF_CAN, SOCK_RAW, CAN_RAW);
if (mBSDSocket < 0) {
exit(-1);
}
/* link socket to specified CAN interface */
addr.can_family = AF_CAN;
strcpy(ifr.ifr_name, interface_cstr);
printf("using SocketCAN device %s\n", ifr.ifr_name);
if (ioctl(mBSDSocket, SIOCGIFINDEX, &ifr) < 0) {
exit(-2);
}
addr.can_ifindex = ifr.ifr_ifindex;
/* bind to socket, so that we can receive messages from it */
if (bind(mBSDSocket, (const struct sockaddr *)&addr, sizeof(addr)) < 0) {
exit(-3);
}
printf("Init ready\n");
i = 0;
do {
frame.can_id = 0x001; //classic 11bit ID data frame
frame.can_dlc = 3;
frame.data[0] = i & 0xFF;
frame.data[1] = (i >> 8) & 0xFF;
frame.data[2] = 2;
frame.data[3] = 3;
frame.data[4] = 4;
frame.data[5] = 5;
frame.data[6] = 6;
frame.data[7] = 7;
/* send the can frame */
nbytes = write(mBSDSocket, &frame, sizeof(frame));
if (nbytes < 0) {
printf("Error %ld\n", nbytes);
}
if (nbytes != sizeof(frame))
{
printf("Wrong Frame size: %ld\n", nbytes);
}
if (nbytes == sizeof(frame))
{
i++;
}
//usleep(500);
} while(i < 10000);
}
