On Tue, Apr 29, 2008 at 08:57:11PM -0400, Avinash Patil wrote:
> Hi,
> 
> We are testing WLAN driver for throughputs.For this we have ported iperf utility to QNX.During execution of the UDP 
transmission tests, we have seen that test terminates abruptly.Here is iperf UDP transmission output.
> 
> 
> 
> [/fcp/bin]# iperf -c 192.168.1.200 -u -b 48M -t 30
> Platform Tester IPC TX ch. opening failed
> ------------------------------------------------------------
> Client connecting to 192.168.1.200, UDP port 5001
> Sending 1470 byte datagrams
> UDP buffer size: 9.00 KByte (default)
> ------------------------------------------------------------
> [  3] local 192.168.1.190 port 65529 connected with 192.168.1.200 port 5001
> write failed: No buffer space available
> [ ID] Interval       Transfer     Bandwidth
> [  3]  0.0- 0.2 sec   808 KBytes  30.8 Mbits/sec
> [  3] Server Report:
> [  3]  0.0- 0.5 sec   808 KBytes  12.1 Mbits/sec  1.260 ms    1/  564 (0.18%)
> [  3] Sent 564 datagrams
> [/fcp/bin]# iperf -c 192.168.1.200 -u -b 30M -t 30
> ------------------------------------------------------------
> Client connecting to 192.168.1.200, UDP port 5001
> Sending 1470 byte datagrams
> UDP buffer size: 9.00 KByte (default)
> ------------------------------------------------------------
> [  3] local 192.168.1.190 port 65528 connected with 192.168.1.200 port 5001
> write failed: No buffer space available
> [ ID] Interval       Transfer     Bandwidth
> [  3]  0.0- 0.2 sec   570 KBytes  25.9 Mbits/sec
> [  3] Server Report:
> [  3]  0.0- 1.5 sec   570 KBytes  3.15 Mbits/sec  4.806 ms    1/  398 (0.25%)
> [  3] Sent 398 datagrams
> 
> Iperf Error output is "write failed: No buffer space available".
> Can anybody shed some light on this?
> We are using io-pkt-v4-hc driver.Atheros driver is LGE NDA driver.
> 

ENOBUFS can be normal under UDP blast type tests.  It probably
means you're getting ahead of the driver and at least one packet
was dropped.  If packets still go out after this it's probably
normal.

-seanb