Hi all, When I use the dpdk lookup function, I met the segment fault problem. Can anybody help to look at why this happens. I will put the aim what I want to do and the related piece of code, and my debug message, This problem is that in dpdk multi process - client and server example, dpdk-2.2.0/examples/multi_process/client_server_mp My aim is that server create a hash table, then share it to client. Client will write the hash table, server will read the hash table. I am using dpdk hash table. What I did is that server create a hash table (table and array entries), return the table address. I use memzone pass the table address to client. In client, the second lookup gets segment fault. The system gets crashed. I will put some related code here. create hash table function: struct onvm_ft* onvm_ft_create(int cnt, int entry_size) { struct rte_hash* hash; struct onvm_ft* ft; struct rte_hash_parameters ipv4_hash_params = { .name = NULL, .entries = cnt, .key_len = sizeof(struct onvm_ft_ipv4_5tuple), .hash_func = NULL, .hash_func_init_val = 0, }; char s[64]; /* create ipv4 hash table. use core number and cycle counter to get a unique name. */ ipv4_hash_params.name = s; ipv4_hash_params.socket_id = rte_socket_id(); snprintf(s, sizeof(s), "onvm_ft_%d-%"PRIu64, rte_lcore_id(), rte_get_tsc_cycles()); hash = rte_hash_create(&ipv4_hash_params); if (hash == NULL) { return NULL; } ft = (struct onvm_ft*)rte_calloc("table", 1, sizeof(struct onvm_ft), 0); if (ft == NULL) { rte_hash_free(hash); return NULL; } ft->hash = hash; ft->cnt = cnt; ft->entry_size = entry_size; /* Create data array for storing values */ ft->data = rte_calloc("entry", cnt, entry_size, 0); if (ft->data == NULL) { rte_hash_free(hash); rte_free(ft); return NULL; } return ft; } related structure: struct onvm_ft { struct rte_hash* hash; char* data; int cnt; int entry_size; }; in server side, I will call the create function, use memzone share it to client. The following is what I do: related variables: struct onvm_ft *sdn_ft; struct onvm_ft **sdn_ft_p; const struct rte_memzone *mz_ftp; sdn_ft = onvm_ft_create(1024, sizeof(struct onvm_flow_entry)); if(sdn_ft == NULL) { rte_exit(EXIT_FAILURE, "Unable to create flow table\n"); } mz_ftp = rte_memzone_reserve(MZ_FTP_INFO, sizeof(struct onvm_ft *), rte_socket_id(), NO_FLAGS); if (mz_ftp == NULL) { rte_exit(EXIT_FAILURE, "Canot reserve memory zone for flow table pointer\n"); } memset(mz_ftp->addr, 0, sizeof(struct onvm_ft *)); sdn_ft_p = mz_ftp->addr; *sdn_ft_p = sdn_ft; In client side: struct onvm_ft *sdn_ft; static void map_flow_table(void) { const struct rte_memzone *mz_ftp; struct onvm_ft **ftp; mz_ftp = rte_memzone_lookup(MZ_FTP_INFO); if (mz_ftp == NULL) rte_exit(EXIT_FAILURE, "Cannot get flow table pointer\n"); ftp = mz_ftp->addr; sdn_ft = *ftp; } The following is my debug message: I set a breakpoint in lookup table line. To narrow down the problem, I just send one flow. So the second time and the first time, the packets are the same. For the first time, it works. I print out the parameters: inside the onvm_ft_lookup function, if there is a related entry, it will return the address by flow_entry. Breakpoint 1, datapath_handle_read (dp=0x7ffff00008c0) at /home/zhangwei1984/openNetVM-master/openNetVM/examples/flow_table/sdn.c:191 191 ret = onvm_ft_lookup(sdn_ft, fk, (char**)&flow_entry); (gdb) print *sdn_ft $1 = {hash = 0x7fff32cce740, data = 0x7fff32cb0480 "", cnt = 1024, entry_size = 56} (gdb) print *fk $2 = {src_addr = 419496202, dst_addr = 453050634, src_port = 53764, dst_port = 11798, proto = 17 '\021'} (gdb) s onvm_ft_lookup (table=0x7fff32cbe4c0, key=0x7fff32b99d00, data=0x7ffff68d2b00) at /home/zhangwei1984/openNetVM-master/openNetVM/onvm/shared/onvm_flow_table.c:151 151 softrss = onvm_softrss(key); (gdb) n 152 printf("software rss %d\n", softrss); (gdb) software rss 403183624 154 tbl_index = rte_hash_lookup_with_hash(table->hash, (const void *)key, softrss); (gdb) print table->hash $3 = (struct rte_hash *) 0x7fff32cce740 (gdb) print *key $4 = {src_addr = 419496202, dst_addr = 453050634, src_port = 53764, dst_port = 11798, proto = 17 '\021'} (gdb) print softrss $5 = 403183624 (gdb) c After I hit c, it will do the second lookup, Breakpoint 1, datapath_handle_read (dp=0x7ffff00008c0) at /home/zhangwei1984/openNetVM-master/openNetVM/examples/flow_table/sdn.c:191 191 ret = onvm_ft_lookup(sdn_ft, fk, (char**)&flow_entry); (gdb) print *sdn_ft $7 = {hash = 0x7fff32cce740, data = 0x7fff32cb0480 "", cnt = 1024, entry_size = 56} (gdb) print *fk $8 = {src_addr = 419496202, dst_addr = 453050634, src_port = 53764, dst_port = 11798, proto = 17 '\021'} (gdb) s onvm_ft_lookup (table=0x7fff32cbe4c0, key=0x7fff32b99c00, data=0x7ffff68d2b00) at /home/zhangwei1984/openNetVM-master/openNetVM/onvm/shared/onvm_flow_table.c:151 151 softrss = onvm_softrss(key); (gdb) n 152 printf("software rss %d\n", softrss); (gdb) n software rss 403183624 154 tbl_index = rte_hash_lookup_with_hash(table->hash, (const void *)key, softrss); (gdb) print table->hash $9 = (struct rte_hash *) 0x7fff32cce740 (gdb) print *key $10 = {src_addr = 419496202, dst_addr = 453050634, src_port = 53764, dst_port = 11798, proto = 17 '\021'} (gdb) print softrss $11 = 403183624 (gdb) n Program received signal SIGSEGV, Segmentation fault. 0x000000000045fb97 in __rte_hash_lookup_bulk () (gdb) bt #0 0x000000000045fb97 in __rte_hash_lookup_bulk () #1 0x0000000000000000 in ?? () From the debug message, the parameters are exactly the same. I do not know why it has the segmentation fault. my lookup function: int onvm_ft_lookup(struct onvm_ft* table, struct onvm_ft_ipv4_5tuple *key, char** data) { int32_t tbl_index; uint32_t softrss; softrss = onvm_softrss(key); printf("software rss %d\n", softrss); tbl_index = rte_hash_lookup_with_hash(table->hash, (const void *)key, softrss); if (tbl_index >= 0) { *data = onvm_ft_get_data(table, tbl_index); return 0; } else { return tbl_index; } }&&jɨ6~w\dƫ}zM9MzEnsڶafjZ'u&E~&m( ^rj)pG (Wnn|ێ]>-~,pDHω; _5ޟ^]JƫMz׭4ӏM4^qy򙨥m( ^rR13v^~yL&Gׯvd}w1^M4N J('j۫z