> On 26 Apr 2018, at 15:34, Amir Kaduri <akadur...@gmail.com> wrote:
> 
> 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
>  
> <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?

“active” means spinning, thus poll should not be used in that case.

>       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).

This seems to be correct

> 
> (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?

Correct

Alfredo

> 
> Thanks,
> Amir
> 
> On Mon, Apr 9, 2018 at 10:51 AM, Alfredo Cardigliano <cardigli...@ntop.org 
> <mailto: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 
>> <mailto: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 
>> <mailto: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 
>> <mailto: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 
>>> <mailto:cardigli...@ntop.org>> wrote:
>>> 
>>> 
>>>> On 31 Oct 2017, at 08:42, Amir Kaduri <akadur...@gmail.com 
>>>> <mailto: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 <mailto: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 
>>>>> <mailto: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 
>>>>> <mailto: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
>>>>> 
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