1 // SPDX-License-Identifier: GPL-2.0 2 #include "util/debug.h" 3 #include "util/evlist.h" 4 #include "util/machine.h" 5 #include "util/map.h" 6 #include "util/symbol.h" 7 #include "util/target.h" 8 #include "util/thread.h" 9 #include "util/thread_map.h" 10 #include "util/lock-contention.h" 11 #include <linux/zalloc.h> 12 #include <linux/string.h> 13 #include <bpf/bpf.h> 14 15 #include "bpf_skel/lock_contention.skel.h" 16 #include "bpf_skel/lock_data.h" 17 18 static struct lock_contention_bpf *skel; 19 20 int lock_contention_prepare(struct lock_contention *con) 21 { 22 int i, fd; 23 int ncpus = 1, ntasks = 1, ntypes = 1, naddrs = 1; 24 struct evlist *evlist = con->evlist; 25 struct target *target = con->target; 26 27 skel = lock_contention_bpf__open(); 28 if (!skel) { 29 pr_err("Failed to open lock-contention BPF skeleton\n"); 30 return -1; 31 } 32 33 bpf_map__set_value_size(skel->maps.stacks, con->max_stack * sizeof(u64)); 34 bpf_map__set_max_entries(skel->maps.lock_stat, con->map_nr_entries); 35 bpf_map__set_max_entries(skel->maps.tstamp, con->map_nr_entries); 36 37 if (con->aggr_mode == LOCK_AGGR_TASK) { 38 bpf_map__set_max_entries(skel->maps.task_data, con->map_nr_entries); 39 bpf_map__set_max_entries(skel->maps.stacks, 1); 40 } else { 41 bpf_map__set_max_entries(skel->maps.task_data, 1); 42 bpf_map__set_max_entries(skel->maps.stacks, con->map_nr_entries); 43 } 44 45 if (target__has_cpu(target)) 46 ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus); 47 if (target__has_task(target)) 48 ntasks = perf_thread_map__nr(evlist->core.threads); 49 if (con->filters->nr_types) 50 ntypes = con->filters->nr_types; 51 52 /* resolve lock name filters to addr */ 53 if (con->filters->nr_syms) { 54 struct symbol *sym; 55 struct map *kmap; 56 unsigned long *addrs; 57 58 for (i = 0; i < con->filters->nr_syms; i++) { 59 sym = machine__find_kernel_symbol_by_name(con->machine, 60 con->filters->syms[i], 61 &kmap); 62 if (sym == NULL) { 63 pr_warning("ignore unknown symbol: %s\n", 64 con->filters->syms[i]); 65 continue; 66 } 67 68 addrs = realloc(con->filters->addrs, 69 (con->filters->nr_addrs + 1) * sizeof(*addrs)); 70 if (addrs == NULL) { 71 pr_warning("memory allocation failure\n"); 72 continue; 73 } 74 75 addrs[con->filters->nr_addrs++] = kmap->unmap_ip(kmap, sym->start); 76 con->filters->addrs = addrs; 77 } 78 naddrs = con->filters->nr_addrs; 79 } 80 81 bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus); 82 bpf_map__set_max_entries(skel->maps.task_filter, ntasks); 83 bpf_map__set_max_entries(skel->maps.type_filter, ntypes); 84 bpf_map__set_max_entries(skel->maps.addr_filter, naddrs); 85 86 if (lock_contention_bpf__load(skel) < 0) { 87 pr_err("Failed to load lock-contention BPF skeleton\n"); 88 return -1; 89 } 90 91 if (target__has_cpu(target)) { 92 u32 cpu; 93 u8 val = 1; 94 95 skel->bss->has_cpu = 1; 96 fd = bpf_map__fd(skel->maps.cpu_filter); 97 98 for (i = 0; i < ncpus; i++) { 99 cpu = perf_cpu_map__cpu(evlist->core.user_requested_cpus, i).cpu; 100 bpf_map_update_elem(fd, &cpu, &val, BPF_ANY); 101 } 102 } 103 104 if (target__has_task(target)) { 105 u32 pid; 106 u8 val = 1; 107 108 skel->bss->has_task = 1; 109 fd = bpf_map__fd(skel->maps.task_filter); 110 111 for (i = 0; i < ntasks; i++) { 112 pid = perf_thread_map__pid(evlist->core.threads, i); 113 bpf_map_update_elem(fd, &pid, &val, BPF_ANY); 114 } 115 } 116 117 if (target__none(target) && evlist->workload.pid > 0) { 118 u32 pid = evlist->workload.pid; 119 u8 val = 1; 120 121 skel->bss->has_task = 1; 122 fd = bpf_map__fd(skel->maps.task_filter); 123 bpf_map_update_elem(fd, &pid, &val, BPF_ANY); 124 } 125 126 if (con->filters->nr_types) { 127 u8 val = 1; 128 129 skel->bss->has_type = 1; 130 fd = bpf_map__fd(skel->maps.type_filter); 131 132 for (i = 0; i < con->filters->nr_types; i++) 133 bpf_map_update_elem(fd, &con->filters->types[i], &val, BPF_ANY); 134 } 135 136 if (con->filters->nr_addrs) { 137 u8 val = 1; 138 139 skel->bss->has_addr = 1; 140 fd = bpf_map__fd(skel->maps.addr_filter); 141 142 for (i = 0; i < con->filters->nr_addrs; i++) 143 bpf_map_update_elem(fd, &con->filters->addrs[i], &val, BPF_ANY); 144 } 145 146 /* these don't work well if in the rodata section */ 147 skel->bss->stack_skip = con->stack_skip; 148 skel->bss->aggr_mode = con->aggr_mode; 149 150 lock_contention_bpf__attach(skel); 151 return 0; 152 } 153 154 int lock_contention_start(void) 155 { 156 skel->bss->enabled = 1; 157 return 0; 158 } 159 160 int lock_contention_stop(void) 161 { 162 skel->bss->enabled = 0; 163 return 0; 164 } 165 166 int lock_contention_read(struct lock_contention *con) 167 { 168 int fd, stack, task_fd, err = 0; 169 struct contention_key *prev_key, key; 170 struct contention_data data = {}; 171 struct lock_stat *st = NULL; 172 struct machine *machine = con->machine; 173 u64 *stack_trace; 174 size_t stack_size = con->max_stack * sizeof(*stack_trace); 175 176 fd = bpf_map__fd(skel->maps.lock_stat); 177 stack = bpf_map__fd(skel->maps.stacks); 178 task_fd = bpf_map__fd(skel->maps.task_data); 179 180 con->lost = skel->bss->lost; 181 182 stack_trace = zalloc(stack_size); 183 if (stack_trace == NULL) 184 return -1; 185 186 if (con->aggr_mode == LOCK_AGGR_TASK) { 187 struct thread *idle = __machine__findnew_thread(machine, 188 /*pid=*/0, 189 /*tid=*/0); 190 thread__set_comm(idle, "swapper", /*timestamp=*/0); 191 } 192 193 /* make sure it loads the kernel map */ 194 map__load(maps__first(machine->kmaps)); 195 196 prev_key = NULL; 197 while (!bpf_map_get_next_key(fd, prev_key, &key)) { 198 struct map *kmap; 199 struct symbol *sym; 200 int idx = 0; 201 s32 stack_id; 202 203 /* to handle errors in the loop body */ 204 err = -1; 205 206 bpf_map_lookup_elem(fd, &key, &data); 207 st = zalloc(sizeof(*st)); 208 if (st == NULL) 209 break; 210 211 st->nr_contended = data.count; 212 st->wait_time_total = data.total_time; 213 st->wait_time_max = data.max_time; 214 st->wait_time_min = data.min_time; 215 216 if (data.count) 217 st->avg_wait_time = data.total_time / data.count; 218 219 st->flags = data.flags; 220 st->addr = key.aggr_key; 221 222 if (con->aggr_mode == LOCK_AGGR_TASK) { 223 struct contention_task_data task; 224 struct thread *t; 225 int pid = key.aggr_key; 226 227 /* do not update idle comm which contains CPU number */ 228 if (st->addr) { 229 bpf_map_lookup_elem(task_fd, &pid, &task); 230 t = __machine__findnew_thread(machine, /*pid=*/-1, pid); 231 thread__set_comm(t, task.comm, /*timestamp=*/0); 232 } 233 goto next; 234 } 235 236 if (con->aggr_mode == LOCK_AGGR_ADDR) { 237 sym = machine__find_kernel_symbol(machine, st->addr, &kmap); 238 if (sym) 239 st->name = strdup(sym->name); 240 goto next; 241 } 242 243 stack_id = key.aggr_key; 244 bpf_map_lookup_elem(stack, &stack_id, stack_trace); 245 246 /* skip lock internal functions */ 247 while (machine__is_lock_function(machine, stack_trace[idx]) && 248 idx < con->max_stack - 1) 249 idx++; 250 251 st->addr = stack_trace[idx]; 252 sym = machine__find_kernel_symbol(machine, st->addr, &kmap); 253 254 if (sym) { 255 unsigned long offset; 256 int ret = 0; 257 258 offset = kmap->map_ip(kmap, st->addr) - sym->start; 259 260 if (offset) 261 ret = asprintf(&st->name, "%s+%#lx", sym->name, offset); 262 else 263 st->name = strdup(sym->name); 264 265 if (ret < 0 || st->name == NULL) 266 break; 267 } else if (asprintf(&st->name, "%#lx", (unsigned long)st->addr) < 0) { 268 break; 269 } 270 271 if (verbose > 0) { 272 st->callstack = memdup(stack_trace, stack_size); 273 if (st->callstack == NULL) 274 break; 275 } 276 next: 277 hlist_add_head(&st->hash_entry, con->result); 278 prev_key = &key; 279 280 /* we're fine now, reset the values */ 281 st = NULL; 282 err = 0; 283 } 284 285 free(stack_trace); 286 if (st) { 287 free(st->name); 288 free(st); 289 } 290 291 return err; 292 } 293 294 int lock_contention_finish(void) 295 { 296 if (skel) { 297 skel->bss->enabled = 0; 298 lock_contention_bpf__destroy(skel); 299 } 300 301 return 0; 302 } 303