[dpdk-users] Attatching global memory pointer to mbuf and sending it to ethernet port.

[JeongHwan Kim]

2020년 1월 3일 (금) 오전 11:26, JeongHwan Kim <kjh.kernel.kr at gmail.com>님이 작성:

>
> 2020년 1월 3일 (금) 오전 11:01, JeongHwan Kim <kjh.kernel.kr at gmail.com>님이 작성:
>
>> No, I'm using only one process which contains several threads.
>>
>> 2020년 1월 3일 (금) 오전 10:20, Stephen Hemminger <stephen at networkplumber.org>님이
>> 작성:
>>
>>> On Fri, 3 Jan 2020 09:11:46 +0900
>>> JeongHwan Kim <kjh.kernel.kr at gmail.com> wrote:
>>>
>>> > Hi, everyone
>>> >
>>> > I'd like to send the contents of global memory through ethernet port
>>> > without memory copying to mbuf.
>>> > So, I attached the pointer of global memory to mbuf's buffer address,
>>> but
>>> > segfault occurs when I send it to ethernet port.
>>> > I 'm using dpdk version 2019.11  and eal config with   "--iova-mode=pa"
>>> > option.
>>> > My hw platform is NXP ls2088a.
>>> >
>>> > My routine is like this:
>>> >
>>> > int buf_len = 100;
>>> > struct rte_mbuf *m = rte_pktmbuf_alloc(mbuf_pool);
>>> > struct rte_mbuf_ext_shared_info *shinfo =
>>> > rte_pktmbuf_ext_shinfo_init_helper(buf_addr, &buf_len,  free_cb,
>>> fcb_arg);
>>> > rte_pktmbuf_attach_extbuf(m, buf_addr, buf_iova, buf_len, shinfo);
>>> > rte_pktmbuf_reset_headroom(m);
>>> > ...
>>> > and sent  "m"  to ethernet, the result was
>>> >
>>> > Thread 4 "lcore-slave-1" received signal SIGSEGV, Segmentation fault.
>>> > [Switching to Thread 0xffffbdb0c910 (LWP 10614)]
>>> > 0x0000aaaaaab73f58 in eth_mbuf_to_sg_fd ()
>>> >
>>> > The buffer was created as follows :
>>> > user_mz = rte_memzone_reserve_aligned("user_mz", size, rte_socket_id(),
>>> >                     RTE_MEMZONE_1GB|RTE_MEMZONE_IOVA_CONTIG,
>>> >                     RTE_CACHE_LINE_SIZE);
>>> > buf_addr = user_mz->addr;
>>> > buf_iova = user_mz->iova;
>>> >
>>> > Please give me a hint for this problem.
>>> > Thanks in advance.
>>> >
>>> > Jeong-Hwa Kim.
>>>
>>> Are you using primary/secondary process model?
>>> Is the memory zone being created in the primary process?
>>>
>>
> I'm not using primary/secondary process model.
> Only primary process exists and  it consists of several threads.
>

I found the weird situation.
First packet I sent was OK, it has an address of the first part of memory
zone.
But after that, the next packet of which address is next the buf length was
fail.