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 42 static int g_trace_fd = -1; 43 static char g_shm_name[64]; 44 45 struct spdk_trace_histories *g_trace_histories; 46 47 void 48 _spdk_trace_record(uint64_t tsc, uint16_t tpoint_id, uint16_t poller_id, uint32_t size, 49 uint64_t object_id, uint64_t arg1) 50 { 51 struct spdk_trace_history *lcore_history; 52 struct spdk_trace_entry *next_entry; 53 unsigned lcore; 54 uint64_t next_circular_entry; 55 56 lcore = spdk_env_get_current_core(); 57 if (lcore >= SPDK_TRACE_MAX_LCORE) { 58 return; 59 } 60 61 lcore_history = spdk_get_per_lcore_history(g_trace_histories, lcore); 62 if (tsc == 0) { 63 tsc = spdk_get_ticks(); 64 } 65 66 lcore_history->tpoint_count[tpoint_id]++; 67 68 /* Get next entry index in the circular buffer */ 69 next_circular_entry = lcore_history->next_entry & (lcore_history->num_entries - 1); 70 next_entry = &lcore_history->entries[next_circular_entry]; 71 next_entry->tsc = tsc; 72 next_entry->tpoint_id = tpoint_id; 73 next_entry->poller_id = poller_id; 74 next_entry->size = size; 75 next_entry->object_id = object_id; 76 next_entry->arg1 = arg1; 77 78 /* Ensure all elements of the trace entry are visible to outside trace tools */ 79 spdk_smp_wmb(); 80 lcore_history->next_entry++; 81 } 82 83 int 84 spdk_trace_init(const char *shm_name, uint64_t num_entries) 85 { 86 int i = 0; 87 int histories_size; 88 uint64_t lcore_offsets[SPDK_TRACE_MAX_LCORE + 1]; 89 90 lcore_offsets[0] = sizeof(struct spdk_trace_flags); 91 for (i = 1; i < (int)SPDK_COUNTOF(lcore_offsets); i++) { 92 lcore_offsets[i] = spdk_get_trace_history_size(num_entries) + lcore_offsets[i - 1]; 93 } 94 histories_size = sizeof(struct spdk_trace_flags) + lcore_offsets[SPDK_TRACE_MAX_LCORE]; 95 96 snprintf(g_shm_name, sizeof(g_shm_name), "%s", shm_name); 97 98 g_trace_fd = shm_open(shm_name, O_RDWR | O_CREAT, 0600); 99 if (g_trace_fd == -1) { 100 fprintf(stderr, "could not shm_open spdk_trace\n"); 101 fprintf(stderr, "errno=%d %s\n", errno, spdk_strerror(errno)); 102 return 1; 103 } 104 105 if (ftruncate(g_trace_fd, histories_size) != 0) { 106 fprintf(stderr, "could not truncate shm\n"); 107 goto trace_init_err; 108 } 109 110 g_trace_histories = mmap(NULL, histories_size, PROT_READ | PROT_WRITE, 111 MAP_SHARED, g_trace_fd, 0); 112 if (g_trace_histories == MAP_FAILED) { 113 fprintf(stderr, "could not mmap shm\n"); 114 goto trace_init_err; 115 } 116 117 /* TODO: On FreeBSD, mlock on shm_open'd memory doesn't seem to work. Docs say that kern.ipc.shm_use_phys=1 118 * should allow it, but forcing that doesn't seem to work either. So for now just skip mlock on FreeBSD 119 * altogether. 120 */ 121 #if defined(__linux__) 122 if (mlock(g_trace_histories, histories_size) != 0) { 123 fprintf(stderr, "Could not mlock shm for tracing - %s.\n", spdk_strerror(errno)); 124 if (errno == ENOMEM) { 125 fprintf(stderr, "Check /dev/shm for old tracing files that can be deleted.\n"); 126 } 127 goto trace_init_err; 128 } 129 #endif 130 131 memset(g_trace_histories, 0, histories_size); 132 133 g_trace_flags = &g_trace_histories->flags; 134 135 g_trace_flags->tsc_rate = spdk_get_ticks_hz(); 136 137 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 138 struct spdk_trace_history *lcore_history; 139 140 g_trace_flags->lcore_history_offsets[i] = lcore_offsets[i]; 141 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 142 lcore_history->lcore = i; 143 lcore_history->num_entries = num_entries; 144 } 145 g_trace_flags->lcore_history_offsets[SPDK_TRACE_MAX_LCORE] = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 146 147 spdk_trace_flags_init(); 148 149 return 0; 150 151 trace_init_err: 152 if (g_trace_histories != MAP_FAILED) { 153 munmap(g_trace_histories, histories_size); 154 } 155 close(g_trace_fd); 156 g_trace_fd = -1; 157 shm_unlink(shm_name); 158 g_trace_histories = NULL; 159 160 return 1; 161 162 } 163 164 void 165 spdk_trace_cleanup(void) 166 { 167 bool unlink; 168 int i; 169 struct spdk_trace_history *lcore_history; 170 171 if (g_trace_histories == NULL) { 172 return; 173 } 174 175 /* 176 * Only unlink the shm if there were no trace_entry recorded. This ensures the file 177 * can be used after this process exits/crashes for debugging. 178 * Note that we have to calculate this value before g_trace_histories gets unmapped. 179 */ 180 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 181 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 182 unlink = lcore_history->entries[0].tsc == 0; 183 if (!unlink) { 184 break; 185 } 186 } 187 188 munmap(g_trace_histories, sizeof(struct spdk_trace_histories)); 189 g_trace_histories = NULL; 190 close(g_trace_fd); 191 192 if (unlink) { 193 shm_unlink(g_shm_name); 194 } 195 } 196