On further investigation on this, I've found an interesting fact. Any changes in the lwip's configuration didn't cause a change, however, when I enabled MEMP_DEBUG the problem was gone, no more of this strange "Trying to send 0 bytes" occurencies and the httpd responded fast and as expected. Of course this isn't a real solution because lwip generates lots of messages when memp_debug is enabled. Anyway, it seems the problem is not inside the httpd but maybe deeper. I really appreciate if anybody has an idea what could be the relation.
Felix Am 17.08.20 um 16:28 schrieb Mário Luzeiro: > Hi Felix, > > I had similar issues but using TLS > https://lists.nongnu.org/archive/html/lwip-users/2020-05/msg00006.html > > I experience the same: some requests are very quick and others take seconds. > ..but didn't found a solution yet. > > I will follow this thread in case someone comes with more suggestions. > > I suggest you can start trying to increase MEMP_NUM_TCP_PCB to the double > I think play with smaller values in TCP_MSS and/or TCP_WND could help.. but > not sure... > > Mario > > ________________________________________ > From: lwip-users <lwip-users-bounces+mrluzeiro=ua...@nongnu.org> on behalf of > Felix Frey <f...@stettbacher.ch> > Sent: 17 August 2020 14:40 > To: lwip-users@nongnu.org > Subject: [lwip-users] very poor performance of httpd > > Hi, > > I've running an application on a STM32F429 using LwIP 2.0.3 and it's httpd. > Basically it works fine, however the performance of the httpd is very poor. > > When the browser does a http request for a total of five files (statically > linked) > with a total amount of 40kB, it takes about 5sec to complete the request. > It seems like the httpd gets stalled. > In the log I can see several of the entrys below: > ----- > 00006.560: http_poll: pcb=0x2000d7b8 hs=0x2000db08 pcb_state=ESTABLISHED > 00006.560: http_poll: try to send more data > 00006.560: http_send: hs=0x2000db08 pcb=0x2000d7b8 left=22030 > 00006.560: Trying to send 0 bytes > 00006.560: Sent 0 bytes > 00006.560: send_data end. > 00006.560: tcp_output > ----- > This is repeated every 500ms for about 2sec until sending moves on. > It looks like it simply doesn't anything during this time. Why?? > > My memory settings are: > #define MEM_LIBC_MALLOC 1 > #define MEMP_NUM_TCP_PCB 8 > #define MEMP_NUM_PBUF 32 > #define TCP_MSS 1460 > #define TCP_WND 2920 > > I've already played with configuration settings, however, it didn't change a > lot. > Can anybody explain this behaviour or even help to improve it? > > Thanks in advance. > Felix > > _______________________________________________ > lwip-users mailing list > lwip-users@nongnu.org > https://lists.nongnu.org/mailman/listinfo/lwip-users > > _______________________________________________ > lwip-users mailing list > lwip-users@nongnu.org > https://lists.nongnu.org/mailman/listinfo/lwip-users > -- Felix Frey Stettbacher Signal Processing Neugutstrasse 54 CH-8600 Dübendorf, Switzerland Fon +41 43 299 57 23 f...@stettbacher.ch http://www.stettbacher.ch _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
