Hi Alfredo, My code is based on libpcap, while pfring's userland examples use pfring APIs directly, therefore things are a bit harder for me.
Short clarification about a related code-line: Please look at the following line: https://github.com/ntop/PF_RING/blob/dev/userland/libpcap-1.8.1/pcap-linux.c#L1875 (1) If I understand it correctly, if wait_for_incoming_packet is true, then pfring_poll() should be called. Don't you want wait_for_incoming_packet to be true in case pf_ring_active_poll is true? Currently, its the opposite (i.e. if pf_ring_active_poll is true, wait_for_incoming_packet will be false thus pfring_poll() won't be called). (2) If the code is ok, then the only way for me to make wait_for_incoming_packet true (for pfring_poll() to be called) is by making handlep->timeout >= 0. Correct? Thanks, Amir On Mon, Apr 9, 2018 at 10:51 AM, Alfredo Cardigliano <cardigli...@ntop.org> wrote: > Hi Amir > if I understand correctly, pfcount_multichannel is working, while in your > application > it seems that poll does not honor the timeout, if this is the case it > seems the problem > is not in the kernel module, I think you should look for differences > between the two applications.. > > Alfredo > > On 9 Apr 2018, at 07:20, Amir Kaduri <akadur...@gmail.com> wrote: > > Hi Alfredo, > > I'm back to investigate/debug this issue in my environment, and maybe > you'll manage to save me some time: > > When I use the example program "pfcount_multichannel", poll-duration works > for me as expected: > For watermark=128, poll-duration=1000, even if less than 128 packets > received, I get them in pfcount_multichannel. > > On the other hand, in my other program (which is a complex one), the > userspace application gets the packets only after 128 packets > aggregated by the ring, regardless the polling rate (which is done always > using 50ms timeout). > > Maybe you can figure out what can "hold" the packets in the ring and > forward them to userspace only when the watermark threshold passes? > Maybe something is missing during initialization? > (for simplicity I'm not using rehash, and not using any filters). > > Thanks > > On Tue, Oct 31, 2017 at 6:32 PM, Alfredo Cardigliano <cardigli...@ntop.org > > wrote: > >> Hi Amir >> that's correct, however for some reason it seems it is not the case in >> your tests. >> >> Alfredo >> >> On 31 Oct 2017, at 12:08, Amir Kaduri <akadur...@gmail.com> wrote: >> >> Thanks. tot_insert apparently works ok. >> >> Regarding function copy_data_to_ring(): >> At the end of it there is the statement: >> if(num_queued_pkts(pfr) >= pfr->poll_num_pkts_watermark) >> wake_up_interruptible(&pfr->ring_slots_waitqueue); >> >> Since watermark is set to 128, and I send <128 packets, this causes them >> to wait in kernel queue. >> But since poll_duration is set to 1 (1 millisecond I assume), I expect >> the condition to check this also (meaning, there are packets in queue but 1 >> millisecond passed and they weren't read), >> the wake_up_interruptible should also be called. No? >> >> Thanks, >> Amir >> >> >> On Tue, Oct 31, 2017 at 10:20 AM, Alfredo Cardigliano < >> cardigli...@ntop.org> wrote: >> >>> >>> >>> On 31 Oct 2017, at 08:42, Amir Kaduri <akadur...@gmail.com> wrote: >>> >>> Hi Alfredo, >>> >>> I'm trying to debug the issue, and I have a question about the code, to >>> make sure that there is no problem there: >>> Specifically, I'm referring to the function "pfring_mod_recv": >>> In order that the line that refers to poll_duration ("pfring_poll(ring, >>> ring->poll_duration)") will be reached, there are 2 conditions that should >>> occur: >>> 1. pfring_there_is_pkt_available(ring) should return false (otherwise, >>> the function returns at the end of the condition). >>> 2. wait_for_incoming_packet should be set to true. >>> Currently, I'm referring to the first one: >>> In order that the macro pfring_there_is_pkt_available(ring) will return >>> false, ring->slots_info->tot_insert should be equal to >>> ring->slots_info->tot_read. >>> What I see in my tests that they don't get equal. I always see that >>> tot_insert>tot_read, and sometimes they get eual when tot_read++ is called >>> but it happens inside the condition, so the "pfring_mod_recv" returns with >>> 1. >>> >>> >>> It seems to be correct. The kernel module inserts packets into the ring >>> increasing tot_insert, the userspace library reads packets from the ring >>> increasing tot_read. This means that if tot_insert == tot_read there is no >>> packet to read. If there is a bug, it should be in the kernel module that >>> is somehow not adding packets to the ring (thus not updating tot_insert). >>> >>> Alfredo >>> >>> I remind that I set the watermark to be high, in order to see the >>> poll_duration takes effect. >>> >>> Could you please approve that you don't see any problem in the code? >>> >>> Thanks, >>> Amir >>> >>> >>> On Thu, Oct 26, 2017 at 12:22 PM, Alfredo Cardigliano < >>> cardigli...@ntop.org> wrote: >>> >>>> Hi Amir >>>> yes, that’s the way it should work, if this is not the case, some >>>> debugging is needed to identify the problem >>>> >>>> Alfredo >>>> >>>> On 26 Oct 2017, at 10:14, Amir Kaduri <akadur...@gmail.com> wrote: >>>> >>>> Basically, the functionality that I would like to have is even if less >>>> than poll-watermark-threshold (default: 128) packets arrives the socket, >>>> they will be forwarded to userland if 1 millisecond has passed. >>>> How can I gain this? Isn't it by using pfring_set_poll_duration()? >>>> >>>> Alfredo, could you please clarify? >>>> >>>> Thanks, >>>> Amir >>>> >>>> On Wed, Oct 18, 2017 at 8:48 PM, Amir Kaduri <akadur...@gmail.com> >>>> wrote: >>>> >>>>> Hi, >>>>> >>>>> I'm using pf_ring 6.6.0 (no ZC) on CentOS 7, on 10G interfaces (ixgbe >>>>> drivers). >>>>> As far as I understand the relation between poll-watermark and >>>>> poll-duration, packets will be queued untill one of comes first: or >>>>> passing >>>>> the poll-watermark packets threshold, or a poll-duration milliseconds has >>>>> passed. >>>>> I set poll-watermark to the maximum (4096) >>>>> (using pfring_set_poll_watermark()) and set poll-duration to the >>>>> minimum (1) (using pfring_set_poll_duration()). >>>>> I've sent 400 packets to the socket. I see that they are received by >>>>> the NIC, but they didn't pass to userland. Only when passing 500 packets, >>>>> a >>>>> chunk of them passed to userland. >>>>> I don't quite understand the behavior: since poll-duration is 1 >>>>> (millisecond I assume), I've expected all the packets to pass to userland >>>>> immediately, even though poll-watermark is much higher. >>>>> >>>>> Can anyone shed some light on the above? >>>>> >>>>> Thanks, >>>>> Amir >>>>> >>>> >>>> _______________________________________________ >>>> Ntop-misc mailing list >>>> Ntop-misc@listgateway.unipi.it >>>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >>>> >>>> >>>> >>>> _______________________________________________ >>>> Ntop-misc mailing list >>>> Ntop-misc@listgateway.unipi.it >>>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >>>> >>> >>> _______________________________________________ >>> Ntop-misc mailing list >>> Ntop-misc@listgateway.unipi.it >>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >>> >>> >>> >>> _______________________________________________ >>> Ntop-misc mailing list >>> Ntop-misc@listgateway.unipi.it >>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >>> >> >> _______________________________________________ >> Ntop-misc mailing list >> Ntop-misc@listgateway.unipi.it >> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >> >> >> _______________________________________________ >> Ntop-misc mailing list >> Ntop-misc@listgateway.unipi.it >> http://listgateway.unipi.it/mailman/listinfo/ntop-misc >> > > _______________________________________________ > Ntop-misc mailing list > Ntop-misc@listgateway.unipi.it > http://listgateway.unipi.it/mailman/listinfo/ntop-misc > > > > _______________________________________________ > Ntop-misc mailing list > Ntop-misc@listgateway.unipi.it > http://listgateway.unipi.it/mailman/listinfo/ntop-misc >
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