Andrew,

Yep, that was exactly it...I was building the client straight out of the main 
source tree and the other application from a shared library. As soon as I made 
sure to build both the same way everything worked out perfectly.

Thanks!!

-Kyle

On 8/20/19, 4:50 PM, "Andrew Rybchenko" <[email protected]> wrote:

    Hello,

    On 8/20/19 7:23 PM, Kyle Ames wrote:
    > I'm running into an issue with primary/secondary DPDK processes. I am 
using DPDK 19.02.
    >
    > I'm trying to explore a setup where one process pulls packets off the 
NIC, and then sends them over a rte_ring for additional processing. Unlike the 
client_server_mp example, I don't need to send the packets out a given port in 
the client. Once the client is done with them they can just go back into the 
mbuf mempool. In order to test this, I took the mp_client example and modified 
it immediately call rte_pktmbuf_free on the packet and not do anything else 
with it after receiving the packet over the shared ring.
    >
    > This works fine for the first 1.5*N packets, where N is the value set for 
the per-lcore cache. Calling rte_pktmbuf_free on the next packet will segfault 
in bucket_enqueue. (backtrace from GDB below)
    >
    > Program received signal SIGSEGV, Segmentation fault.
    > 0x0000000000593822 in bucket_enqueue ()
    > Missing separate debuginfos, use: debuginfo-install 
glibc-2.17-196.el7_4.2.x86_64 libgcc-4.8.5-16.el7.x86_64 
numactl-libs-2.0.9-6.el7_2.x86_64
    > (gdb) backtrace
    > #0  0x0000000000593822 in bucket_enqueue ()

    I doubt that bucket mempool is used intentionally. If so, I guess shared
    libraries are
    used and mempool libraries are picked up in different order and drivers
    got different
    mempool ops indexes. As far as I remember there is a documentation which
    says
    that shared libraries should be specified in the same order in primary
    and secondary
    process.

    Andrew.

    > #1  0x00000000004769f1 in rte_mempool_ops_enqueue_bulk (n=1, 
obj_table=0x7fffffffe398, mp=<optimized out>)
    >      at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mempool.h:704
    > #2  __mempool_generic_put (cache=<optimized out>, n=1, 
obj_table=0x7fffffffe398, mp=<optimized out>)
    >      at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mempool.h:1263
    > #3  rte_mempool_generic_put (cache=<optimized out>, n=1, 
obj_table=0x7fffffffe398, mp=<optimized out>)
    >      at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mempool.h:1285
    > #4  rte_mempool_put_bulk (n=1, obj_table=0x7fffffffe398, mp=<optimized 
out>) at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mempool.h:1308
    > #5  rte_mempool_put (obj=0x100800040, mp=<optimized out>) at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mempool.h:1326
    > #6  rte_mbuf_raw_free (m=0x100800040) at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mbuf.h:1185
    > #7  rte_pktmbuf_free_seg (m=<optimized out>) at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mbuf.h:1807
    > #8  rte_pktmbuf_free (m=0x100800040) at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/build/include/rte_mbuf.h:1828
    > #9  main (argc=<optimized out>, argv=<optimized out>)
    >      at 
/home/kames/code/3rdparty/dpdk-hack/dpdk/examples/multi_process/client_server_mp/mp_client/client.c:90
    >
    > I changed the size a few times, and the packet in the client that 
segfaults on free is always the 1.5N'th packet. This happens even if I set the 
cache_size to zero on mbuf pool creation. (The first mbuf free immediately 
segfaults)
    >
    > I'm a bit stuck at the moment. There's clearly a pattern/interaction of 
some sort, but I don't know what it is or what to do about it. Is this even the 
right approach for such a scenario?
    >
    > -Kyle Ames

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