1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright (c) Intel Corporation. 3 * All rights reserved. 4 */ 5 6 #include "spdk/stdinc.h" 7 8 #include "spdk/env.h" 9 #include "spdk/string.h" 10 #include "spdk/trace.h" 11 #include "spdk/util.h" 12 #include "spdk/barrier.h" 13 #include "spdk/log.h" 14 #include "spdk/cpuset.h" 15 16 static int g_trace_fd = -1; 17 static char g_shm_name[64]; 18 19 struct spdk_trace_histories *g_trace_histories; 20 21 static inline struct spdk_trace_entry * 22 get_trace_entry(struct spdk_trace_history *history, uint64_t offset) 23 { 24 return &history->entries[offset & (history->num_entries - 1)]; 25 } 26 27 void 28 _spdk_trace_record(uint64_t tsc, uint16_t tpoint_id, uint16_t poller_id, uint32_t size, 29 uint64_t object_id, int num_args, ...) 30 { 31 struct spdk_trace_history *lcore_history; 32 struct spdk_trace_entry *next_entry; 33 struct spdk_trace_entry_buffer *buffer; 34 struct spdk_trace_tpoint *tpoint; 35 struct spdk_trace_argument *argument; 36 unsigned lcore, i, offset, num_entries, arglen, argoff, curlen; 37 uint64_t intval; 38 void *argval; 39 va_list vl; 40 41 lcore = spdk_env_get_current_core(); 42 if (lcore >= SPDK_TRACE_MAX_LCORE) { 43 return; 44 } 45 46 lcore_history = spdk_get_per_lcore_history(g_trace_histories, lcore); 47 if (tsc == 0) { 48 tsc = spdk_get_ticks(); 49 } 50 51 lcore_history->tpoint_count[tpoint_id]++; 52 53 tpoint = &g_trace_flags->tpoint[tpoint_id]; 54 /* Make sure that the number of arguments passed matches tracepoint definition */ 55 if (tpoint->num_args != num_args) { 56 assert(0 && "Unexpected number of tracepoint arguments"); 57 return; 58 } 59 60 /* Get next entry index in the circular buffer */ 61 next_entry = get_trace_entry(lcore_history, lcore_history->next_entry); 62 next_entry->tsc = tsc; 63 next_entry->tpoint_id = tpoint_id; 64 next_entry->poller_id = poller_id; 65 next_entry->size = size; 66 next_entry->object_id = object_id; 67 68 num_entries = 1; 69 buffer = (struct spdk_trace_entry_buffer *)next_entry; 70 /* The initial offset needs to be adjusted by the fields present in the first entry 71 * (poller_id, size, etc.). 72 */ 73 offset = offsetof(struct spdk_trace_entry, args) - 74 offsetof(struct spdk_trace_entry_buffer, data); 75 76 va_start(vl, num_args); 77 for (i = 0; i < tpoint->num_args; ++i) { 78 argument = &tpoint->args[i]; 79 switch (argument->type) { 80 case SPDK_TRACE_ARG_TYPE_STR: 81 argval = va_arg(vl, void *); 82 arglen = strnlen((const char *)argval, argument->size - 1) + 1; 83 break; 84 case SPDK_TRACE_ARG_TYPE_INT: 85 case SPDK_TRACE_ARG_TYPE_PTR: 86 if (argument->size == 8) { 87 intval = va_arg(vl, uint64_t); 88 } else { 89 intval = va_arg(vl, uint32_t); 90 } 91 argval = &intval; 92 arglen = argument->size; 93 break; 94 default: 95 assert(0 && "Invalid trace argument type"); 96 return; 97 } 98 99 /* Copy argument's data. For some argument types (strings) user is allowed to pass a 100 * value that is either larger or smaller than what's defined in the tracepoint's 101 * description. If the value is larger, we'll truncate it, while if it's smaller, 102 * we'll only fill portion of the buffer, without touching the rest. For instance, 103 * if the definition marks an argument as 40B and user passes 12B string, we'll only 104 * copy 13B (accounting for the NULL terminator). 105 */ 106 argoff = 0; 107 while (argoff < argument->size) { 108 /* Current buffer is full, we need to acquire another one */ 109 if (offset == sizeof(buffer->data)) { 110 buffer = (struct spdk_trace_entry_buffer *) get_trace_entry( 111 lcore_history, 112 lcore_history->next_entry + num_entries); 113 buffer->tpoint_id = SPDK_TRACE_MAX_TPOINT_ID; 114 buffer->tsc = tsc; 115 num_entries++; 116 offset = 0; 117 } 118 119 curlen = spdk_min(sizeof(buffer->data) - offset, argument->size - argoff); 120 if (argoff < arglen) { 121 assert(argval != NULL); 122 memcpy(&buffer->data[offset], (uint8_t *)argval + argoff, 123 spdk_min(curlen, arglen - argoff)); 124 } 125 126 offset += curlen; 127 argoff += curlen; 128 } 129 130 /* Make sure that truncated strings are NULL-terminated */ 131 if (argument->type == SPDK_TRACE_ARG_TYPE_STR) { 132 assert(offset > 0); 133 buffer->data[offset - 1] = '\0'; 134 } 135 } 136 va_end(vl); 137 138 /* Ensure all elements of the trace entry are visible to outside trace tools */ 139 spdk_smp_wmb(); 140 lcore_history->next_entry += num_entries; 141 } 142 143 int 144 spdk_trace_init(const char *shm_name, uint64_t num_entries) 145 { 146 uint32_t i = 0; 147 int histories_size; 148 uint64_t lcore_offsets[SPDK_TRACE_MAX_LCORE + 1] = { 0 }; 149 struct spdk_cpuset cpuset = {}; 150 151 /* 0 entries requested - skip trace initialization */ 152 if (num_entries == 0) { 153 return 0; 154 } 155 156 spdk_cpuset_zero(&cpuset); 157 histories_size = sizeof(struct spdk_trace_flags); 158 SPDK_ENV_FOREACH_CORE(i) { 159 spdk_cpuset_set_cpu(&cpuset, i, true); 160 lcore_offsets[i] = histories_size; 161 histories_size += spdk_get_trace_history_size(num_entries); 162 } 163 lcore_offsets[SPDK_TRACE_MAX_LCORE] = histories_size; 164 165 snprintf(g_shm_name, sizeof(g_shm_name), "%s", shm_name); 166 167 g_trace_fd = shm_open(shm_name, O_RDWR | O_CREAT, 0600); 168 if (g_trace_fd == -1) { 169 SPDK_ERRLOG("could not shm_open spdk_trace\n"); 170 SPDK_ERRLOG("errno=%d %s\n", errno, spdk_strerror(errno)); 171 return 1; 172 } 173 174 if (ftruncate(g_trace_fd, histories_size) != 0) { 175 SPDK_ERRLOG("could not truncate shm\n"); 176 goto trace_init_err; 177 } 178 179 g_trace_histories = mmap(NULL, histories_size, PROT_READ | PROT_WRITE, 180 MAP_SHARED, g_trace_fd, 0); 181 if (g_trace_histories == MAP_FAILED) { 182 SPDK_ERRLOG("could not mmap shm\n"); 183 goto trace_init_err; 184 } 185 186 /* TODO: On FreeBSD, mlock on shm_open'd memory doesn't seem to work. Docs say that kern.ipc.shm_use_phys=1 187 * should allow it, but forcing that doesn't seem to work either. So for now just skip mlock on FreeBSD 188 * altogether. 189 */ 190 #if defined(__linux__) 191 if (mlock(g_trace_histories, histories_size) != 0) { 192 SPDK_ERRLOG("Could not mlock shm for tracing - %s.\n", spdk_strerror(errno)); 193 if (errno == ENOMEM) { 194 SPDK_ERRLOG("Check /dev/shm for old tracing files that can be deleted.\n"); 195 } 196 goto trace_init_err; 197 } 198 #endif 199 200 memset(g_trace_histories, 0, histories_size); 201 202 g_trace_flags = &g_trace_histories->flags; 203 204 g_trace_flags->tsc_rate = spdk_get_ticks_hz(); 205 206 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 207 struct spdk_trace_history *lcore_history; 208 209 g_trace_flags->lcore_history_offsets[i] = lcore_offsets[i]; 210 if (lcore_offsets[i] == 0) { 211 continue; 212 } 213 assert(spdk_cpuset_get_cpu(&cpuset, i)); 214 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 215 lcore_history->lcore = i; 216 lcore_history->num_entries = num_entries; 217 } 218 g_trace_flags->lcore_history_offsets[SPDK_TRACE_MAX_LCORE] = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 219 220 spdk_trace_flags_init(); 221 222 return 0; 223 224 trace_init_err: 225 if (g_trace_histories != MAP_FAILED) { 226 munmap(g_trace_histories, histories_size); 227 } 228 close(g_trace_fd); 229 g_trace_fd = -1; 230 shm_unlink(shm_name); 231 g_trace_histories = NULL; 232 233 return 1; 234 235 } 236 237 void 238 spdk_trace_cleanup(void) 239 { 240 bool unlink = true; 241 int i; 242 struct spdk_trace_history *lcore_history; 243 244 if (g_trace_histories == NULL) { 245 return; 246 } 247 248 /* 249 * Only unlink the shm if there were no trace_entry recorded. This ensures the file 250 * can be used after this process exits/crashes for debugging. 251 * Note that we have to calculate this value before g_trace_histories gets unmapped. 252 */ 253 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 254 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 255 if (lcore_history == NULL) { 256 continue; 257 } 258 unlink = lcore_history->entries[0].tsc == 0; 259 if (!unlink) { 260 break; 261 } 262 } 263 264 munmap(g_trace_histories, sizeof(struct spdk_trace_histories)); 265 g_trace_histories = NULL; 266 close(g_trace_fd); 267 268 if (unlink) { 269 shm_unlink(g_shm_name); 270 } 271 } 272