ChibiOS Free Embedded RTOS

Now I see! Thanks Giovanni!
Then I will give the new API a full run too see if I can remove the USB Serial.

I have done a benchmark with different options for USB CDC PC TX and Chibios RX:
The new driver is very good (versus old chibios 3 driver) only for packet >= 1000 bytes (which reach about 850KB/s with USB 2.0 FS on STM32F405@168MHz)
It is strange but during test with my PC at different time (probably related to my PC) the performance on small packet have changed see bench_chibios4_test3.txt (with big buffer we reach pratically 1MB/s so not far from 1.1MB/s theory for USB 2.0 FS)

bench_chibios3.txt
https://github.com/bvernoux/hydrafw/com ... c365248dd1
HydraFW (HydraBus) v0.7-beta-3-g81f925c 2016-04-26
Kernel: ChibiOS 3.0.0dev
Compiler: GCC 4.7.4 20130913 (release) [ARM/embedded-4_7-branch revision 202601]

int cmd_debug_test_rx(t_hydra_console *con, t_tokenline_parsed *p)
{
(void)p;

cprintf(con, "Test debug-rx started, stop it with UBTN + Key\r\n");
while(1) {
/* Exit if User Button is pressed */
if (USER_BUTTON) {
break;
}
get_char(con);
}
return TRUE;
}

packet_Length: 64 num_Packets: 1000
TX Time: 0.21900 s
TX Bytes/s: 292237 TX KBytes/s: 285.39

packet_Length: 128 num_Packets: 500
TX Time: 0.18700 s
TX Bytes/s: 342245 TX KBytes/s: 334.22

packet_Length: 256 num_Packets: 500
TX Time: 0.24900 s
TX Bytes/s: 514056 TX KBytes/s: 502.01

packet_Length: 500 num_Packets: 500
TX Time: 0.43700 s
TX Bytes/s: 572082 TX KBytes/s: 558.67

packet_Length: 512 num_Packets: 500
TX Time: 0.46800 s
TX Bytes/s: 547008 TX KBytes/s: 534.19

packet_Length: 1000 num_Packets: 500
TX Time: 0.85800 s
TX Bytes/s: 582750 TX KBytes/s: 569.09

packet_Length: 1008 num_Packets: 500
TX Time: 0.85800 s
TX Bytes/s: 587412 TX KBytes/s: 573.65

packet_Length: 1024 num_Packets: 500
TX Time: 0.87300 s
TX Bytes/s: 586483 TX KBytes/s: 572.74

packet_Length: 1280 num_Packets: 400
TX Time: 0.85800 s
TX Bytes/s: 596736 TX KBytes/s: 582.75

packet_Length: 2000 num_Packets: 400
TX Time: 1.32600 s
TX Bytes/s: 603318 TX KBytes/s: 589.18

packet_Length: 2048 num_Packets: 400
TX Time: 1.37300 s
TX Bytes/s: 596649 TX KBytes/s: 582.67

packet_Length: 3000 num_Packets: 400
TX Time: 1.98100 s
TX Bytes/s: 605754 TX KBytes/s: 591.56

bench_chibios4_test1.txt
https://github.com/bvernoux/hydrafw/tree/dev_chibios
https://github.com/bvernoux/hydrafw/com ... 70c8e82c64
HydraFW (HydraBus) v0.7-beta-7-g1a35534-dirty 2016-05-01
Kernel: ChibiOS 4.0.0
Compiler: GCC 4.7.4 20130913 (release) [ARM/embedded-4_7-branch revision 202601]

#define SERIAL_USB_BUFFERS_SIZE 1280
// Modified bench code
int cmd_debug_test_rx(t_hydra_console *con, t_tokenline_parsed *p)
{
(void)p;
BaseSequentialStream* chp = con->bss;

cprintf(con, "Test debug-rx started, stop it with UBTN + Key\r\n");
while(1) {
chnRead(chp, (uint8_t *)g_sbuf, sizeof(g_sbuf) - 1);

/* Exit if User Button is pressed */
if (USER_BUTTON) {
break;
}
//get_char(con);
}
return TRUE;
}

packet_Length: 64 num_Packets: 1000
TX Time: 0.22200 s
TX Bytes/s: 288288 TX KBytes/s: 281.53

packet_Length: 128 num_Packets: 500
TX Time: 0.17200 s
TX Bytes/s: 372093 TX KBytes/s: 363.37

packet_Length: 256 num_Packets: 500
TX Time: 0.25000 s
TX Bytes/s: 512000 TX KBytes/s: 500.00

packet_Length: 500 num_Packets: 500
TX Time: 0.37900 s
TX Bytes/s: 659630 TX KBytes/s: 644.17

packet_Length: 512 num_Packets: 500
TX Time: 0.40300 s
TX Bytes/s: 635235 TX KBytes/s: 620.35

packet_Length: 1000 num_Packets: 500
TX Time: 0.65900 s
TX Bytes/s: 758725 TX KBytes/s: 740.94

packet_Length: 1008 num_Packets: 500
TX Time: 0.67800 s
TX Bytes/s: 743362 TX KBytes/s: 725.94

packet_Length: 1024 num_Packets: 500
TX Time: 0.68700 s
TX Bytes/s: 745269 TX KBytes/s: 727.80

packet_Length: 1280 num_Packets: 400
TX Time: 0.65900 s
TX Bytes/s: 776934 TX KBytes/s: 758.73

packet_Length: 2000 num_Packets: 400
TX Time: 0.99600 s
TX Bytes/s: 803212 TX KBytes/s: 784.39

packet_Length: 2048 num_Packets: 400
TX Time: 1.02400 s
TX Bytes/s: 799999 TX KBytes/s: 781.25

packet_Length: 3000 num_Packets: 400
TX Time: 1.43800 s
TX Bytes/s: 834492 TX KBytes/s: 814.93

bench_chibios4_test2.txt
https://github.com/bvernoux/hydrafw/tree/dev_chibios
https://github.com/bvernoux/hydrafw/com ... 70c8e82c64
HydraFW (HydraBus) v0.7-beta-7-g1a35534-dirty 2016-05-01
Kernel: ChibiOS 4.0.0
Compiler: GCC 4.7.4 20130913 (release) [ARM/embedded-4_7-branch revision 202601]

#define SERIAL_USB_BUFFERS_SIZE 256
// Modified bench code
int cmd_debug_test_rx(t_hydra_console *con, t_tokenline_parsed *p)
{
(void)p;
BaseSequentialStream* chp = con->bss;

cprintf(con, "Test debug-rx started, stop it with UBTN + Key\r\n");
while(1) {
chnRead(chp, (uint8_t *)g_sbuf, sizeof(g_sbuf) - 1);

/* Exit if User Button is pressed */
if (USER_BUTTON) {
break;
}
//get_char(con);
}
return TRUE;
}

packet_Length: 64 num_Packets: 1000
TX Time: 1.00000 s
TX Bytes/s: 64000 TX KBytes/s: 62.50

packet_Length: 128 num_Packets: 500
TX Time: 0.49900 s
TX Bytes/s: 128256 TX KBytes/s: 125.25

packet_Length: 256 num_Packets: 500
TX Time: 0.49900 s
TX Bytes/s: 256512 TX KBytes/s: 250.50

packet_Length: 500 num_Packets: 500
TX Time: 0.50000 s
TX Bytes/s: 500000 TX KBytes/s: 488.28

packet_Length: 512 num_Packets: 500
TX Time: 0.50000 s
TX Bytes/s: 512000 TX KBytes/s: 500.00

packet_Length: 1000 num_Packets: 500
TX Time: 0.57300 s
TX Bytes/s: 872600 TX KBytes/s: 852.15

packet_Length: 1008 num_Packets: 500
TX Time: 0.58300 s
TX Bytes/s: 864493 TX KBytes/s: 844.23

packet_Length: 1024 num_Packets: 500
TX Time: 0.58800 s
TX Bytes/s: 870748 TX KBytes/s: 850.34

packet_Length: 1280 num_Packets: 400
TX Time: 0.57900 s
TX Bytes/s: 884283 TX KBytes/s: 863.56

packet_Length: 2000 num_Packets: 400
TX Time: 0.84200 s
TX Bytes/s: 950118 TX KBytes/s: 927.85

packet_Length: 2048 num_Packets: 400
TX Time: 0.88900 s
TX Bytes/s: 921484 TX KBytes/s: 899.89

packet_Length: 3000 num_Packets: 400
TX Time: 1.26100 s
TX Bytes/s: 951625 TX KBytes/s: 929.32

bench_chibios4_test3.txt
https://github.com/bvernoux/hydrafw/tree/dev_chibios
https://github.com/bvernoux/hydrafw/com ... 70c8e82c64
HydraFW (HydraBus) v0.7-beta-7-g1a35534-dirty 2016-05-01
Kernel: ChibiOS 4.0.0
Compiler: GCC 4.7.4 20130913 (release) [ARM/embedded-4_7-branch revision 202601]

#define SERIAL_USB_BUFFERS_SIZE 512
or
#define SERIAL_USB_BUFFERS_SIZE 1280
// Modified bench code
int cmd_debug_test_rx(t_hydra_console *con, t_tokenline_parsed *p)
{
(void)p;
BaseSequentialStream* chp = con->bss;

cprintf(con, "Test debug-rx started, stop it with UBTN + Key\r\n");
while(1) {
chnRead(chp, (uint8_t *)g_sbuf, sizeof(g_sbuf) - 1);

/* Exit if User Button is pressed */
if (USER_BUTTON) {
break;
}
//get_char(con);
}
return TRUE;
}

packet_Length: 64 num_Packets: 1000
TX Time: 0.99900 s
TX Bytes/s: 64064 TX KBytes/s: 62.56

packet_Length: 128 num_Packets: 500
TX Time: 0.49900 s
TX Bytes/s: 128256 TX KBytes/s: 125.25

packet_Length: 256 num_Packets: 500
TX Time: 0.49900 s
TX Bytes/s: 256512 TX KBytes/s: 250.50

packet_Length: 500 num_Packets: 500
TX Time: 0.50000 s
TX Bytes/s: 500000 TX KBytes/s: 488.28

packet_Length: 512 num_Packets: 500
TX Time: 0.50000 s
TX Bytes/s: 512000 TX KBytes/s: 500.00

packet_Length: 1000 num_Packets: 500
TX Time: 0.63200 s
TX Bytes/s: 791139 TX KBytes/s: 772.60

packet_Length: 1008 num_Packets: 500
TX Time: 0.59800 s
TX Bytes/s: 842809 TX KBytes/s: 823.06

packet_Length: 1024 num_Packets: 500
TX Time: 0.62300 s
TX Bytes/s: 821829 TX KBytes/s: 802.57

packet_Length: 1280 num_Packets: 400
TX Time: 0.61500 s
TX Bytes/s: 832520 TX KBytes/s: 813.01

packet_Length: 2000 num_Packets: 400
TX Time: 0.85700 s
TX Bytes/s: 933489 TX KBytes/s: 911.61

packet_Length: 2048 num_Packets: 400
TX Time: 0.86600 s
TX Bytes/s: 945958 TX KBytes/s: 923.79

packet_Length: 3000 num_Packets: 400
TX Time: 1.26300 s
TX Bytes/s: 950118 TX KBytes/s: 927.85

Hi,

Thanks for data.

I also experienced changes in benchmarks, I think it is more related to host than the STM32 device.

In your numbers by "packet length" you mean the size of the exchanged buffers? I think the packet size is always 64.

In the new serial_usb driver there is also another parameter that could affect performance for low lengths:

#define SERIAL_USB_BUFFERS_NUMBER 2

Just another note, in order to test the USB performance you could try the direct USB API and not use serial_usb, see that USB_RAW demo under \testhal\STM32\STM32F7xx\USB_RAW

Giovanni

I have done some test changing => #define SERIAL_USB_BUFFERS_NUMBER 2 to 4 or even 8 but I have not seen any speed increase for short packet < 1000 bytes.

I have used this python script: https://gist.github.com/bvernoux/09cf99 ... 6715fb65bf
I suspect bad performance on packet < 1000 bytes could be linked to Python "slowness" or to my test script (I use Python 2.7.10)
For information computer configuration used for tests is Asus N56VZ for more details see http://www.userbenchmark.com/UserRun/565656

I will do more test maybe writing a native multi-platform C test software using libusb.
I will also change the firmware side in order to test both TX & RX on USB and trying also your hint under \testhal\STM32\STM32F7xx\USB_RAW

Best Regards,
Benjamin