Hi Ed, Thanks again. I guess I will have to bite the bullet and start an implementation of the RAW_API. I really did not think that my really quite modest requirements would not be met by the sockets version.
John Robbins Quoting "Pisano, Edward A" <[EMAIL PROTECTED]>: > Hi John, > In experimenting with lwIP on MicroBlaze, I saw some significant > performance improvements when I setup and enabled the data cache and > instruction cache. Also, there are some other architectural things that > can be done such as using the multi-channel memory (mch_opb_ddr) and > placing certain structures that are accessed frequently, but run a small > risk of be flushed from cache occasionally, into the dlmb section. I've > been told the LMB is almost as fast as cache. > > In this environment with SOCKETS_API, I was to delay 10ms between 1400 > byte UDP datagrams transmitted from my laptop and echo'd back by the > Spartan 3E before seeing any packet loss. > > Of late, I've extended the experiments to using the lwIP RAW_API. It is > much, much faster. I've reduced the delay between UDP datagrams as low > as 2ms for small file (50KB) echo back. In RAW_API, there's no > xilkernel and you must take care of lwIP memory management yourself. > > Regards, > Ed > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Sunday, September 24, 2006 6:40 PM > To: Mailing list for lwIP users > Subject: RE: [lwip-users] Slow response times in Microblaze Webserver > example > > I compared timing for the same data transfer using a Netburner SB72 card > > (Coldfire MCF5272 @ 66MHz) with the Microblaze (Spartan3e starter kit @ > 50MHz) > as the server. The client at the end of a short crossover cable was a > newish > IBM laptop running XP and reporting a 100bpsconnection, the code being > written > in C++ for .Net. In response to a GET request the server sent 1260 bytes > > (actually 315 integers). To see the output change in the client but > without > distorting the lwIP timing, the server program changed only the first > and last > integer values. > > The following lines show one transfer for each system. The request > period was > 500 millisecond. The first delta time therefore is the difference > between this > period and the time required for the previous transfer. > > Netburner > > > 460385 IP IBM-F3860BD49B6.1081 > 192.168.0.200.80: > S > 1367389610:1367389610(0) win 65535 <mss > "1460,nop,nop,sackOK>" > 657 IP 192.168.0.200.80 > IBM-F3860BD49B6.1081: > S > 19071019:19071019(0) ack 1367389611 win 0 > <mss > "1460,nop,nop,nop,eol>" > 40 IP IBM-F3860BD49B6.1081 > 192.168.0.200.80: > . > ack 1 win 65535 > 926 IP 192.168.0.200.80 > IBM-F3860BD49B6.1081: > . > ack 1 win 4644 > 35211 IP IBM-F3860BD49B6.1081 > 192.168.0.200.80: > P > 1:31(30) ack 1 win 65535 > 2252 IP 192.168.0.200.80 > IBM-F3860BD49B6.1081: > P > 1:1261(1260) ack 31 win 4614 > 31 IP 192.168.0.200.80 > IBM-F3860BD49B6.1081: > F > 1261:1261(0) ack 31 win 0 > 31 IP IBM-F3860BD49B6.1081 > 192.168.0.200.80: > . > ack 1262 win 64275 > 39148 > > > Microblaze > > > 349914 IP IBM-F3860BD49B6.1147 > 192.168.0.200.80: > S > 3416876235:3416876235(0) win 65535 <mss > "1460,nop,nop,sackOK>" > 21994 IP 192.168.0.200.80 > IBM-F3860BD49B6.1147: > S > 32027:32027(0) ack 3416876236 win 16384 <mss > 1460> > 50 IP IBM-F3860BD49B6.1147 > 192.168.0.200.80: > . > ack 1 win 65535 > 35108 IP IBM-F3860BD49B6.1147 > 192.168.0.200.80: > P > 1:31(30) ack 1 win 65535 > 20632 IP 192.168.0.200.80 > IBM-F3860BD49B6.1147: > . > ack 31 win 16354 > 25924 IP 192.168.0.200.80 > IBM-F3860BD49B6.1147: > . > ack 31 win 16384 > 32843 IP 192.168.0.200.80 > IBM-F3860BD49B6.1147: > P > 1:1261(1260) ack 31 win 16384 > 15552 IP 192.168.0.200.80 > IBM-F3860BD49B6.1147: > F > 1261:1261(0) ack 31 win 16384 > 52 IP IBM-F3860BD49B6.1147 > 192.168.0.200.80: > . > ack 1262 win 64275 > 152155 > > > The data transfer time for the Microblaze (33 msec) is more than ten > times > slower than the Netburner (2.2 msec). The overall time for the complete > transaction for the Microblaze was 152 msec against the Netburner's 39 > msecs. > > I am sure I must be doing something wrong. These results are really most > > disappointing as I was hoping to replace the Netburner with a Microblaze > based > solution for our new DAQ system. > > I am using the same xilkernel and lwIP settings as in the Webserver > example for > the S3e board. Are there any different optimisations I should be using? > > Any help would be most appreciated. > > John Robbins. > > > Quoting [EMAIL PROTECTED]: > > > > > Hi Ed, > > > > Thanks for fast response. > > > > I removed the xil_printf messages and turned off LWIP_DEBUG. The Ping > time > > dropped from 215 to 16 millisecs. > > > > However when I run the GET request the time spent in the read function > is > > still > > 2820 millisecs except for the very first time when both the client and > server > > > > programs are loaded and run, then the time is 26 millisecs. Restarting > either > > > > the client or server without restarting the other still results in the > long > > delay time. The other lwIP functions called by the Webserver code(eg > accept, > > > > write) seem to be fast. > > > > Without the RS232 messages, the short response time when both server > and > > client > > are restarted seems to be very consistent whereas before the short > response > > time was seen only under these conditions but then not always. > > > > Any more thoughts on resolving this problem would be most appreciated. > > > > John Robbins > > > > Quoting "Pisano, Edward A" <[EMAIL PROTECTED]>: > > > > > 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 > > > > > > > > > > > > > > > _______________________________________________ > > 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 > > > _______________________________________________ > 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
