Serge Orlov wrote: > Paul Sijben wrote: >> Serge Orlov wrote: >>> Paul Sijben wrote: >>>> I am stumped by the following problem. I have a large multi-threaded >>>> server accepting communications on one UDP port (chosen for its supposed >>>> speed). >>>> >>>> I have been profiling the code and found that the UDP communication is >>>> my biggest drain on performance! Communication where the client and the >>>> server are on the same machine still takes 300ms or sometimes much more >>>> per packet on an Athlon64 3000+ running Linux (Fedora Core 5 x64). >>> [snip] >>> >>>> buf, address = socket.recvfrom(8192) >>> I'm not an expert here, but I AFAIK UDP packet size should be kept >>> below 512 bytes otherwise it can cause fragmentation and hence all the >>> slow stuff like acknoledgements, timeouts, etc... >>> >> good point in general but in practice they are in this case. but this is >> less of a problem on the loopback interface anyway. > > Isn't it still controlled by MTU even on the loopback? What is your MTU > on the loopback? > lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1
eth0 Link encap:Ethernet HWaddr 00:14:85:35:A4:5D inet addr:192.168.0.124 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::214:85ff:fe35:a45d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 -- http://mail.python.org/mailman/listinfo/python-list