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_duratio >>> n()). >>> 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 >
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