there is a weird problem as title when using dpdk,
When I use rte_pktmbuf_alloc(struct rte_mempool *) and already verify the return value of rte_pktmbuf_pool_create() is not NULL, the process receive segmentation fault.
Follow
ing message is output of gdb in dpdk source code:
Thread 1 "osw" received signal SIGSEGV, Segmentation fault.
0x00000000005e9f41 in __mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdec8, mp=0x101a7df00)at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1449
1449 if (unlikely(cache == NULL || n >= cache->size))
(gdb) p cache
$1 = (struct rte_mempool_cache *) 0x1a7dfc000000000
(gdb) bt
0 0x00000000005e9f41 in __mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1449
1 rte_mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1517
2 rte_mempool_get_bulk (n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1552
3 rte_mempool_get (obj_p=0x7fffffffdeb8, mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1578
4 rte_mbuf_raw_alloc (mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mbuf.h:586
5 rte_pktmbuf_alloc (mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mbuf.h:896
And I dig into rte_mempool.h:
and change line 1449-1450
1449 if (unlikely(cache == NULL || n >= cache->size))
1450 goto ring_dequeue;
to
1449 if (unlikely(cache == NULL))
1450 goto ring_dequeue;
1451 if (unlikely(n >= cache->size))
1452 goto ring_dequeue;
and it also fail at line 1451
the gdb output message after changing:
Thread 1 "osw" received signal SIGSEGV, Segmentation fault.
__mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1451
1451 if (unlikely(n >= cache->size))
(gdb) p cache
$1 = (struct rte_mempool_cache *) 0x1a7dfc000000000
(gdb) bt
0 __mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1451
1 rte_mempool_generic_get (cache=0x1a7dfc000000000, n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1519
2 rte_mempool_get_bulk (n=1, obj_table=0x7fffffffdeb8, mp=0x101a7df00)
at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1554
3 rte_mempool_get (obj_p=0x7fffffffdeb8, mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mempool.h:1580
4 rte_mbuf_raw_alloc (mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mbuf.h:586
5 rte_pktmbuf_alloc (mp=0x101a7df00) at /root/dpdk-20.05/x86_64-native-linuxapp-gcc/include/rte_mbuf.h:896
6 main (argc=<optimized out>, argv=<optimized out>) at ofpd.c:150
(gdb) p cache->size
Cannot access memory at address 0x1a7dfc000000000
It looks like the memory address “cache” pointer stored is not NULL but it actually is a NULL pointer.
I have no idea that why does the "cache" pointer address be non zero at prefix 4 bytes and zero at postfix 4 bytes.
The DPDK version is 20.05, I also tried 18.11 and 19.11.
OS is CentOS 8.1 kernel is 4.18.0-147.el8.x86_64.
CPU is AMD EPYC 7401P.
#define RING_SIZE 16384
#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 512
int main(int argc, char **argv)
{
int ret;
uint16_t portid;
unsigned cpu_id = 1;
struct rte_mempool *tmp;
int arg = rte_eal_init(argc, argv);
if (arg < 0)
rte_exit(EXIT_FAILURE, "Cannot init EAL: %s\n", rte_strerror(rte_errno));
if (rte_lcore_count() < 10)
rte_exit(EXIT_FAILURE, "We need at least 10 cores.\n");
argc -= arg;
argv += arg;
/* Creates a new mempool in memory to hold the mbufs. */
tmp = rte_pktmbuf_pool_create("TMP", NUM_MBUFS, MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
if (tmp == NULL)
rte_exit(EXIT_FAILURE, "Cannot create mbuf pool, %s\n", rte_strerror(rte_errno));
printf("tmp addr = %x\n", tmp);
struct rte_mbuf *test = rte_pktmbuf_alloc(tmp);
rte_exit(EXIT_FAILURE, "end\n");
}
I have ever faced same problem when using the return pointer of getifaddrs(), it also got segmentation fault, I had to shift the pointer address like
ifa->ifa_addr = (struct sockaddr *)((uintptr_t)(ifa->ifa_addr) >> 32);
and then it can work normally.
Thereforer, I think this is not dpdk specific issue.
Does anyone know this issue?
Thanks.
I am able to run this without any error by modifying your code for
alloc
Test on:
CPU: Intel(R) Xeon(R) CPU E5-2699
OS: 4.15.0-101-generic
GCC: 7.5.0
DPDK version: 19.11.2, dpdk mainline
Library mode: static
code:
int main(int argc, char **argv)
{
int ret = 0;
struct rte_mempool *tmp;
int arg = rte_eal_init(argc, argv);
if (arg < 0)
rte_exit(EXIT_FAILURE, "Cannot init EAL: %s\n", rte_strerror(rte_errno));
if (rte_lcore_count() < 10)
rte_exit(EXIT_FAILURE, "We need at least 10 cores.\n");
argc -= arg;
argv += arg;
/* Creates a new mempool in memory to hold the mbufs. */
tmp = rte_pktmbuf_pool_create("TMP", NUM_MBUFS, MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
if (tmp == NULL)
rte_exit(EXIT_FAILURE, "Cannot create mbuf pool, %s\n", rte_strerror(rte_errno));
printf("tmp addr = %p\n", tmp);
struct rte_mbuf *test = rte_pktmbuf_alloc(tmp);
if (test == NULL)
rte_exit(EXIT_FAILURE, "end\n");
return ret;
}
[EDIT-1] based on the comment Brydon Gibson
Note:
THE
and Brydon
are different individuals and might be facing similar on the different code bases.Requested @BrydonGibson to open the ticket with relevant information and environment details as it might be different.
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