BTW, the following is my backtrace when the system crashes. Program received signal SIGSEGV, Segmentation fault.
0x00000000004883ab in rte_hash_reset (h=0x0) at /home/zhangwei1984/timopenNetVM/dpdk-2.2.0/lib/librte_hash/rte_cuckoo_hash.c:444 444while (rte_ring_dequeue(h->free_slots, &ptr) == 0) (gdb) bt #0 0x00000000004883ab in rte_hash_reset (h=0x0) at /home/zhangwei1984/timopenNetVM/dpdk-2.2.0/lib/librte_hash/rte_cuckoo_hash.c:444 #1 0x000000000048fdfb in rte_hash_lookup_with_hash (h=0x7fff32cce740, key=0x7fffffffe220, sig=403183624) at /home/zhangwei1984/timopenNetVM/dpdk-2.2.0/lib/librte_hash/rte_cuckoo_hash.c:771 #2 0x000000000042b551 in onvm_ft_lookup_with_hash (table=0x7fff32cbe4c0, pkt=0x7fff390ea9c0, data=0x7fffffffe298) at /home/zhangwei1984/openNetVM-master/openNetVM/onvm/shared/onvm_flow_table.c:104 #3 0x000000000042b8c3 in onvm_flow_dir_get_with_hash (table=0x7fff32cbe4c0, pkt=0x7fff390ea9c0, flow_entry=0x7fffffffe298) at /home/zhangwei1984/openNetVM-master/openNetVM/onvm/shared/onvm_flow_dir.c:14 #4 0x00000000004251d7 in packet_handler (pkt=0x7fff390ea9c0, meta=0x7fff390eaa00) at /home/zhangwei1984/openNetVM-master/openNetVM/examples/flow_table/flow_table.c:212 #5 0x0000000000429502 in onvm_nf_run () #6 0x00000000004253f1 in main (argc=1, argv=0x7fffffffe648) at /home/zhangwei1984/openNetVM-master/openNetVM/examples/flow_table/flow_table.c:272 (gdb) I met a problem which I used the DPDK hash table for multi processes. One started as primary process and the other as secondary process. I based on the client and server multiprocess example. My aim is that server creates a hash table, then share it to the client. The client will read and write the hash table, and the server will read the hash table. I use rte_calloc allocate the space for hash table, use memzone tells the client the hash table address. But once I add an entry into the hash table, calling "lookup" function will have the segment fault. But for the lookup function, I have exactly the same parameters for lookup when the first time calls the lookup. If I create the hash table inside the client, everything works correctly. I put pieces of codes for server and client codes related to the hash table. I have spent almost 3 days on this bug. But there is no any clue which can help to solve this bug. If any of you can give some suggestions, I will be appreciated. I post the question into the mail list, but have not yet got any reply. 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 ?? ()