Hi John, I had seen similar slow response with the WebServer example. It turned out to be the debug output messages. The RS-232 output has a significant slowing effect on lwIP. In my case, ping replies were taking 1700ms to 3400ms on the Spartan 3E. I turned off LWIP_DEBUG and commented out my own xil_print() statements. Ping replies quickly dropped to 17ms-25ms.
Regards, Ed -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, September 19, 2006 5:47 AM To: [email protected] Subject: [lwip-users] Slow response times in Microblaze Webserver example Dear All, I have been testing a program modified from the Webserver example for the Xilinx Spartan3e Starter Kit. A client application on a PC connected to the board via a crossover cable issues a GET command, to which the server should respond with a short string, about 50 bytes. The problem that I am finding is that, although the response is occasionally very fast, 99% of the time the response may take several seconds. Since my eventual application is a fairly fast data acquisition requirement, this is a problem. To debug this, I first removed the mfs part of the Webserver example, then added GPIO calls to the LEDs before and after the read function in processConnection. Using an Ant8 logic analyser, I found that the time needed in this function was very occasionally 30 - 40 millisecs but almost always around 2900 millisecs. Using gdb, I traced the delay to the call in netconn_recv() to sys_mbox_fetch() which blocks for 3 seconds, then all the rest of code executes as expected. The fast response seems only to occur the first time both the client and server are run. In XPS I selected the debug output option, set the rs232 speed to 115kbs and directed the output to a file. During the block period the system appears to emit at least six "tcp_slowtmr:procssing active pcb messages" interspersed with some timeout messages. In case I was doing something wrong in the client code, I used the same program to talk to a Netburner card, issuing the same response to a GET request. The delays were of the order of a few millisecs. So I am sure I am doing something stupid in the server code and would really appreciate any help. JOhn Robbins. _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
