The NAPI thread is fast enough dequeueing from the NIC, but then it find the ring full and discards the packets (drops).
Alfredo > On 06 Nov 2014, at 23:25, Behrooz Shafiee <[email protected]> wrote: > > Hi Alfredo, > > I got your point but I don't understand the point of flow-control then! If > I'm slow then pfring should slow down reading from NIC so NIC will notice the > slowdown and sends a pause frame to the sender! Is there anything wrong with > this logic? > > Thanks, > > On Thu, Nov 6, 2014 at 5:21 PM, Alfredo Cardigliano <[email protected] > <mailto:[email protected]>> wrote: > Hi Behrooz > your application is not fast enough dequeueing packets from the ring, thus > the drops. > You should try increasing the ring size (via insmod parameter), it helps at > least with spikes. > > Alfredo > >> On 06 Nov 2014, at 23:01, Behrooz Shafiee <[email protected] >> <mailto:[email protected]>> wrote: >> >> Hello Pavel, >> >> I'm not sure what do you mean but here is the output of to during run: >> >> top - 16:58:48 up 2:27, 8 users, load average: 0.25, 0.59, 0.81 >> Tasks: 211 total, 4 running, 207 sleeping, 0 stopped, 0 zombie >> %Cpu(s): 7.3 us, 7.1 sy, 0.0 ni, 84.6 id, 0.2 wa, 0.8 hi, 0.0 si, 0.0 >> st >> KiB Mem: 16334304 total, 5330972 used, 11003332 free, 112164 buffers >> KiB Swap: 10207228 total, 0 used, 10207228 free. 2101892 cached Mem >> >> I just realized that if I use pfring_stats when I receive the whole 5000 >> packet the number of drops is 0 and when I don't receive all of them the >> number of drops in the stats is around 2000-3000. >> >> On Thu, Nov 6, 2014 at 4:54 PM, Pavel Odintsov <[email protected] >> <mailto:[email protected]>> wrote: >> Hello! >> >> Could you show top header and htop output? >> >> On Fri, Nov 7, 2014 at 12:48 AM, Behrooz Shafiee <[email protected] >> <mailto:[email protected]>> wrote: >> > Hi everyone, >> > >> > I have implemented a small transmission protocol over pfring. I rely on >> > the >> > Ethernet flow control meaning that I assume that in the same subnet I won't >> > loose any packet (I've no router so no queueing...). Everything was fine >> > until I did some stress test as follows. >> > I have a rcvThread which block on pfring_recv() function for each one >> > incoming packet and process it. I start a huge number of other threads(e.g >> > 5000) and each of them send a req to server through pfring_send (resp is >> > one >> > packet). And then server replies with 5000 packet. most of the time i >> > receive the 5000 packets but sometimes I miss some of them. For example I >> > reach the line after pfring_recv() 4503 times. I thought this is due to >> > overflow in the NIC but I use intel pro which has both rx/tx flow pause >> > frame on and I actually used a packet dump tool (such as wireshark) and I >> > see the packets are being received by the NIC. So I assume they get lost >> > somewhere a long the line from NIC to pfring_recv() function. Can anyone >> > help me what might have gone wrong? >> > >> > PS. I use pfring in normal mode not DNA >> > >> > >> > Thanks, >> > -- >> > Behrooz >> > >> > _______________________________________________ >> > Ntop-misc mailing list >> > [email protected] <mailto:[email protected]> >> > http://listgateway.unipi.it/mailman/listinfo/ntop-misc >> > <http://listgateway.unipi.it/mailman/listinfo/ntop-misc> >> >> >> >> -- >> Sincerely yours, Pavel Odintsov >> _______________________________________________ >> Ntop-misc mailing list >> [email protected] <mailto:[email protected]> >> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >> <http://listgateway.unipi.it/mailman/listinfo/ntop-misc> >> >> >> >> -- >> Behrooz >> _______________________________________________ >> Ntop-misc mailing list >> [email protected] <mailto:[email protected]> >> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >> <http://listgateway.unipi.it/mailman/listinfo/ntop-misc> > > _______________________________________________ > Ntop-misc mailing list > [email protected] <mailto:[email protected]> > http://listgateway.unipi.it/mailman/listinfo/ntop-misc > <http://listgateway.unipi.it/mailman/listinfo/ntop-misc> > > > > -- > Behrooz > _______________________________________________ > Ntop-misc mailing list > [email protected] > http://listgateway.unipi.it/mailman/listinfo/ntop-misc
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