Hi Harold I meant optimal performance w.r.t packets per second. If there is no loss without app fragmentation at target pps with say 8 RX queues, and same results in missing packets with app fragmentation then the issue might me somewhere else. What is RSS configuration, you should not take transport headers into account ETH_RSS_IPV4 is safe otherwise different app fragments of same packet can go to different RX queues.
On Tue, Jul 18, 2017 at 3:06 PM, Harold Demure <harold.demur...@gmail.com> wrote: > Hello Shyam, > Thank you for your suggestion. I will try what you say. However, this > problem arises only with specific workloads. For example, if the clients > only send requests of 1 frame, everything runs smoothly even with 16 active > queues. My problem arises only with bigger payloads and multiple queues. > Shouldn't this suggest that the problem is not "simply" that my NIC drops > packets with > X active queues? > > Regards, > Harold > > 2017-07-18 7:50 GMT+02:00 Shyam Shrivastav <shrivastav.sh...@gmail.com>: > >> As I understand the problem disappears with 1 RX queue on server. You can >> reduce number of queues on server from 8 and arrive at an optimal value >> without packet loss. >> For intel 82599 NIC packet loss is experienced with more than 4 RX >> queues, this was reported in dpdk dev or user mailing list, read in >> archives sometime back while looking for similar information with 82599. >> >> On Tue, Jul 18, 2017 at 4:54 AM, Harold Demure <harold.demur...@gmail.com >> > wrote: >> >>> Hello again, >>> I tried to convert my statically defined buffers into buffers allocated >>> through rte_malloc (as discussed in the previous email, see quoted text). >>> Unfortunately, the problem is still there :( >>> Regards, >>> Harold >>> >>> >>> >>> > >>> > 2. How do you know you have the packet loss? >>> > >>> > >>> > *I know it because some fragmented packets never get reassembled >>> fully. If >>> > I print the packets seen by the server I see something like "PCKT_ID >>> 10 >>> > FRAG 250, PCKT_ID 10 FRAG 252". And FRAG 251 is never printed.* >>> > >>> > *Actually, something strange that happens sometimes is that a core >>> > receives fragments of two packets and, say, receives frag 1 of >>> packet X, >>> > frag 2 of packet Y, frag 3 of packet X, frag 4 of packet Y.* >>> > *Or that, after "losing" a fragment for packet X, I only see printed >>> > fragments with EVEN frag_id for that packet X. At least for a while.* >>> > >>> > *This led me also to consider a bug in my implementation (I don't >>> > experience this problem if I run with a SINGLE client thread). However, >>> > with smaller payloads, even fragmented, everything runs smoothly.* >>> > *If you have any suggestions for tests to run to spot a possible bug >>> in my >>> > implementation, It'd be more than welcome!* >>> > >>> > *MORE ON THIS: the buffers in which I store the packets taken from RX >>> are >>> > statically defined arrays, like struct rte_mbuf* temp_mbuf[SIZE]. >>> SIZE >>> > can be pretty high (say, 10K entries), and there are 3 of those arrays >>> per >>> > core. Can it be that, somehow, they mess up the memory layout (e.g., >>> they >>> > intersect)?* >>> > >>> >> >> >