1 /*- 2 * BSD LICENSE 3 * 4 * Copyright (c) Intel Corporation. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * * Neither the name of Intel Corporation nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include "spdk/stdinc.h" 35 36 #include "spdk/env.h" 37 #include "spdk/string.h" 38 #include "spdk/trace.h" 39 #include "spdk/util.h" 40 #include "spdk/barrier.h" 41 #include "spdk/log.h" 42 43 static int g_trace_fd = -1; 44 static char g_shm_name[64]; 45 46 struct spdk_trace_histories *g_trace_histories; 47 48 void 49 _spdk_trace_record(uint64_t tsc, uint16_t tpoint_id, uint16_t poller_id, uint32_t size, 50 uint64_t object_id, uint64_t arg1) 51 { 52 struct spdk_trace_history *lcore_history; 53 struct spdk_trace_entry *next_entry; 54 unsigned lcore; 55 uint64_t next_circular_entry; 56 57 lcore = spdk_env_get_current_core(); 58 if (lcore >= SPDK_TRACE_MAX_LCORE) { 59 return; 60 } 61 62 lcore_history = spdk_get_per_lcore_history(g_trace_histories, lcore); 63 if (tsc == 0) { 64 tsc = spdk_get_ticks(); 65 } 66 67 lcore_history->tpoint_count[tpoint_id]++; 68 69 /* Get next entry index in the circular buffer */ 70 next_circular_entry = lcore_history->next_entry & (lcore_history->num_entries - 1); 71 next_entry = &lcore_history->entries[next_circular_entry]; 72 next_entry->tsc = tsc; 73 next_entry->tpoint_id = tpoint_id; 74 next_entry->poller_id = poller_id; 75 next_entry->size = size; 76 next_entry->object_id = object_id; 77 next_entry->arg1 = arg1; 78 79 /* Ensure all elements of the trace entry are visible to outside trace tools */ 80 spdk_smp_wmb(); 81 lcore_history->next_entry++; 82 } 83 84 int 85 spdk_trace_init(const char *shm_name, uint64_t num_entries) 86 { 87 int i = 0; 88 int histories_size; 89 uint64_t lcore_offsets[SPDK_TRACE_MAX_LCORE + 1]; 90 91 /* 0 entries requested - skip trace initialization */ 92 if (num_entries == 0) { 93 return 0; 94 } 95 96 lcore_offsets[0] = sizeof(struct spdk_trace_flags); 97 for (i = 1; i < (int)SPDK_COUNTOF(lcore_offsets); i++) { 98 lcore_offsets[i] = spdk_get_trace_history_size(num_entries) + lcore_offsets[i - 1]; 99 } 100 histories_size = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 101 102 snprintf(g_shm_name, sizeof(g_shm_name), "%s", shm_name); 103 104 g_trace_fd = shm_open(shm_name, O_RDWR | O_CREAT, 0600); 105 if (g_trace_fd == -1) { 106 SPDK_ERRLOG("could not shm_open spdk_trace\n"); 107 SPDK_ERRLOG("errno=%d %s\n", errno, spdk_strerror(errno)); 108 return 1; 109 } 110 111 if (ftruncate(g_trace_fd, histories_size) != 0) { 112 SPDK_ERRLOG("could not truncate shm\n"); 113 goto trace_init_err; 114 } 115 116 g_trace_histories = mmap(NULL, histories_size, PROT_READ | PROT_WRITE, 117 MAP_SHARED, g_trace_fd, 0); 118 if (g_trace_histories == MAP_FAILED) { 119 SPDK_ERRLOG("could not mmap shm\n"); 120 goto trace_init_err; 121 } 122 123 /* TODO: On FreeBSD, mlock on shm_open'd memory doesn't seem to work. Docs say that kern.ipc.shm_use_phys=1 124 * should allow it, but forcing that doesn't seem to work either. So for now just skip mlock on FreeBSD 125 * altogether. 126 */ 127 #if defined(__linux__) 128 if (mlock(g_trace_histories, histories_size) != 0) { 129 SPDK_ERRLOG("Could not mlock shm for tracing - %s.\n", spdk_strerror(errno)); 130 if (errno == ENOMEM) { 131 SPDK_ERRLOG("Check /dev/shm for old tracing files that can be deleted.\n"); 132 } 133 goto trace_init_err; 134 } 135 #endif 136 137 memset(g_trace_histories, 0, histories_size); 138 139 g_trace_flags = &g_trace_histories->flags; 140 141 g_trace_flags->tsc_rate = spdk_get_ticks_hz(); 142 143 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 144 struct spdk_trace_history *lcore_history; 145 146 g_trace_flags->lcore_history_offsets[i] = lcore_offsets[i]; 147 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 148 lcore_history->lcore = i; 149 lcore_history->num_entries = num_entries; 150 } 151 g_trace_flags->lcore_history_offsets[SPDK_TRACE_MAX_LCORE] = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 152 153 spdk_trace_flags_init(); 154 155 return 0; 156 157 trace_init_err: 158 if (g_trace_histories != MAP_FAILED) { 159 munmap(g_trace_histories, histories_size); 160 } 161 close(g_trace_fd); 162 g_trace_fd = -1; 163 shm_unlink(shm_name); 164 g_trace_histories = NULL; 165 166 return 1; 167 168 } 169 170 void 171 spdk_trace_cleanup(void) 172 { 173 bool unlink; 174 int i; 175 struct spdk_trace_history *lcore_history; 176 177 if (g_trace_histories == NULL) { 178 return; 179 } 180 181 /* 182 * Only unlink the shm if there were no trace_entry recorded. This ensures the file 183 * can be used after this process exits/crashes for debugging. 184 * Note that we have to calculate this value before g_trace_histories gets unmapped. 185 */ 186 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 187 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 188 unlink = lcore_history->entries[0].tsc == 0; 189 if (!unlink) { 190 break; 191 } 192 } 193 194 munmap(g_trace_histories, sizeof(struct spdk_trace_histories)); 195 g_trace_histories = NULL; 196 close(g_trace_fd); 197 198 if (unlink) { 199 shm_unlink(g_shm_name); 200 } 201 } 202