Hi all, there is a weird problem as title,
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.
Following message is out of gdb:
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.
Does anyone know this issue?
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.
I have reduce my code in program to just calling rte_eal_init() then
rte_pktmbuf_pool_create() and rte_pktmbuf_alloc().
Thanks.
