root/tools/perf/tests/perf-record.c

DEFINITIONS

1. sched__get_first_possible_cpu
2. test__PERF_RECORD

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <inttypes.h>
   4 #include <linux/string.h>
   5 /* For the CLR_() macros */
   6 #include <pthread.h>
   7 
   8 #include <sched.h>
   9 #include "evlist.h"
  10 #include "evsel.h"
  11 #include "debug.h"
  12 #include "record.h"
  13 #include "tests.h"
  14 #include "util/mmap.h"
  15 
  16 static int sched__get_first_possible_cpu(pid_t pid, cpu_set_t *maskp)
  17 {
  18         int i, cpu = -1, nrcpus = 1024;
  19 realloc:
  20         CPU_ZERO(maskp);
  21 
  22         if (sched_getaffinity(pid, sizeof(*maskp), maskp) == -1) {
  23                 if (errno == EINVAL && nrcpus < (1024 << 8)) {
  24                         nrcpus = nrcpus << 2;
  25                         goto realloc;
  26                 }
  27                 perror("sched_getaffinity");
  28                         return -1;
  29         }
  30 
  31         for (i = 0; i < nrcpus; i++) {
  32                 if (CPU_ISSET(i, maskp)) {
  33                         if (cpu == -1)
  34                                 cpu = i;
  35                         else
  36                                 CPU_CLR(i, maskp);
  37                 }
  38         }
  39 
  40         return cpu;
  41 }
  42 
  43 int test__PERF_RECORD(struct test *test __maybe_unused, int subtest __maybe_unused)
  44 {
  45         struct record_opts opts = {
  46                 .target = {
  47                         .uid = UINT_MAX,
  48                         .uses_mmap = true,
  49                 },
  50                 .no_buffering = true,
  51                 .mmap_pages   = 256,
  52         };
  53         cpu_set_t cpu_mask;
  54         size_t cpu_mask_size = sizeof(cpu_mask);
  55         struct evlist *evlist = perf_evlist__new_dummy();
  56         struct evsel *evsel;
  57         struct perf_sample sample;
  58         const char *cmd = "sleep";
  59         const char *argv[] = { cmd, "1", NULL, };
  60         char *bname, *mmap_filename;
  61         u64 prev_time = 0;
  62         bool found_cmd_mmap = false,
  63              found_coreutils_mmap = false,
  64              found_libc_mmap = false,
  65              found_vdso_mmap = false,
  66              found_ld_mmap = false;
  67         int err = -1, errs = 0, i, wakeups = 0;
  68         u32 cpu;
  69         int total_events = 0, nr_events[PERF_RECORD_MAX] = { 0, };
  70         char sbuf[STRERR_BUFSIZE];
  71 
  72         if (evlist == NULL) /* Fallback for kernels lacking PERF_COUNT_SW_DUMMY */
  73                 evlist = perf_evlist__new_default();
  74 
  75         if (evlist == NULL) {
  76                 pr_debug("Not enough memory to create evlist\n");
  77                 goto out;
  78         }
  79 
  80         /*
  81          * Create maps of threads and cpus to monitor. In this case
  82          * we start with all threads and cpus (-1, -1) but then in
  83          * perf_evlist__prepare_workload we'll fill in the only thread
  84          * we're monitoring, the one forked there.
  85          */
  86         err = perf_evlist__create_maps(evlist, &opts.target);
  87         if (err < 0) {
  88                 pr_debug("Not enough memory to create thread/cpu maps\n");
  89                 goto out_delete_evlist;
  90         }
  91 
  92         /*
  93          * Prepare the workload in argv[] to run, it'll fork it, and then wait
  94          * for perf_evlist__start_workload() to exec it. This is done this way
  95          * so that we have time to open the evlist (calling sys_perf_event_open
  96          * on all the fds) and then mmap them.
  97          */
  98         err = perf_evlist__prepare_workload(evlist, &opts.target, argv, false, NULL);
  99         if (err < 0) {
 100                 pr_debug("Couldn't run the workload!\n");
 101                 goto out_delete_evlist;
 102         }
 103 
 104         /*
 105          * Config the evsels, setting attr->comm on the first one, etc.
 106          */
 107         evsel = evlist__first(evlist);
 108         perf_evsel__set_sample_bit(evsel, CPU);
 109         perf_evsel__set_sample_bit(evsel, TID);
 110         perf_evsel__set_sample_bit(evsel, TIME);
 111         perf_evlist__config(evlist, &opts, NULL);
 112 
 113         err = sched__get_first_possible_cpu(evlist->workload.pid, &cpu_mask);
 114         if (err < 0) {
 115                 pr_debug("sched__get_first_possible_cpu: %s\n",
 116                          str_error_r(errno, sbuf, sizeof(sbuf)));
 117                 goto out_delete_evlist;
 118         }
 119 
 120         cpu = err;
 121 
 122         /*
 123          * So that we can check perf_sample.cpu on all the samples.
 124          */
 125         if (sched_setaffinity(evlist->workload.pid, cpu_mask_size, &cpu_mask) < 0) {
 126                 pr_debug("sched_setaffinity: %s\n",
 127                          str_error_r(errno, sbuf, sizeof(sbuf)));
 128                 goto out_delete_evlist;
 129         }
 130 
 131         /*
 132          * Call sys_perf_event_open on all the fds on all the evsels,
 133          * grouping them if asked to.
 134          */
 135         err = evlist__open(evlist);
 136         if (err < 0) {
 137                 pr_debug("perf_evlist__open: %s\n",
 138                          str_error_r(errno, sbuf, sizeof(sbuf)));
 139                 goto out_delete_evlist;
 140         }
 141 
 142         /*
 143          * mmap the first fd on a given CPU and ask for events for the other
 144          * fds in the same CPU to be injected in the same mmap ring buffer
 145          * (using ioctl(PERF_EVENT_IOC_SET_OUTPUT)).
 146          */
 147         err = evlist__mmap(evlist, opts.mmap_pages);
 148         if (err < 0) {
 149                 pr_debug("evlist__mmap: %s\n",
 150                          str_error_r(errno, sbuf, sizeof(sbuf)));
 151                 goto out_delete_evlist;
 152         }
 153 
 154         /*
 155          * Now that all is properly set up, enable the events, they will
 156          * count just on workload.pid, which will start...
 157          */
 158         evlist__enable(evlist);
 159 
 160         /*
 161          * Now!
 162          */
 163         perf_evlist__start_workload(evlist);
 164 
 165         while (1) {
 166                 int before = total_events;
 167 
 168                 for (i = 0; i < evlist->core.nr_mmaps; i++) {
 169                         union perf_event *event;
 170                         struct mmap *md;
 171 
 172                         md = &evlist->mmap[i];
 173                         if (perf_mmap__read_init(md) < 0)
 174                                 continue;
 175 
 176                         while ((event = perf_mmap__read_event(md)) != NULL) {
 177                                 const u32 type = event->header.type;
 178                                 const char *name = perf_event__name(type);
 179 
 180                                 ++total_events;
 181                                 if (type < PERF_RECORD_MAX)
 182                                         nr_events[type]++;
 183 
 184                                 err = perf_evlist__parse_sample(evlist, event, &sample);
 185                                 if (err < 0) {
 186                                         if (verbose > 0)
 187                                                 perf_event__fprintf(event, stderr);
 188                                         pr_debug("Couldn't parse sample\n");
 189                                         goto out_delete_evlist;
 190                                 }
 191 
 192                                 if (verbose > 0) {
 193                                         pr_info("%" PRIu64" %d ", sample.time, sample.cpu);
 194                                         perf_event__fprintf(event, stderr);
 195                                 }
 196 
 197                                 if (prev_time > sample.time) {
 198                                         pr_debug("%s going backwards in time, prev=%" PRIu64 ", curr=%" PRIu64 "\n",
 199                                                  name, prev_time, sample.time);
 200                                         ++errs;
 201                                 }
 202 
 203                                 prev_time = sample.time;
 204 
 205                                 if (sample.cpu != cpu) {
 206                                         pr_debug("%s with unexpected cpu, expected %d, got %d\n",
 207                                                  name, cpu, sample.cpu);
 208                                         ++errs;
 209                                 }
 210 
 211                                 if ((pid_t)sample.pid != evlist->workload.pid) {
 212                                         pr_debug("%s with unexpected pid, expected %d, got %d\n",
 213                                                  name, evlist->workload.pid, sample.pid);
 214                                         ++errs;
 215                                 }
 216 
 217                                 if ((pid_t)sample.tid != evlist->workload.pid) {
 218                                         pr_debug("%s with unexpected tid, expected %d, got %d\n",
 219                                                  name, evlist->workload.pid, sample.tid);
 220                                         ++errs;
 221                                 }
 222 
 223                                 if ((type == PERF_RECORD_COMM ||
 224                                      type == PERF_RECORD_MMAP ||
 225                                      type == PERF_RECORD_MMAP2 ||
 226                                      type == PERF_RECORD_FORK ||
 227                                      type == PERF_RECORD_EXIT) &&
 228                                      (pid_t)event->comm.pid != evlist->workload.pid) {
 229                                         pr_debug("%s with unexpected pid/tid\n", name);
 230                                         ++errs;
 231                                 }
 232 
 233                                 if ((type == PERF_RECORD_COMM ||
 234                                      type == PERF_RECORD_MMAP ||
 235                                      type == PERF_RECORD_MMAP2) &&
 236                                      event->comm.pid != event->comm.tid) {
 237                                         pr_debug("%s with different pid/tid!\n", name);
 238                                         ++errs;
 239                                 }
 240 
 241                                 switch (type) {
 242                                 case PERF_RECORD_COMM:
 243                                         if (strcmp(event->comm.comm, cmd)) {
 244                                                 pr_debug("%s with unexpected comm!\n", name);
 245                                                 ++errs;
 246                                         }
 247                                         break;
 248                                 case PERF_RECORD_EXIT:
 249                                         goto found_exit;
 250                                 case PERF_RECORD_MMAP:
 251                                         mmap_filename = event->mmap.filename;
 252                                         goto check_bname;
 253                                 case PERF_RECORD_MMAP2:
 254                                         mmap_filename = event->mmap2.filename;
 255                                 check_bname:
 256                                         bname = strrchr(mmap_filename, '/');
 257                                         if (bname != NULL) {
 258                                                 if (!found_cmd_mmap)
 259                                                         found_cmd_mmap = !strcmp(bname + 1, cmd);
 260                                                 if (!found_coreutils_mmap)
 261                                                         found_coreutils_mmap = !strcmp(bname + 1, "coreutils");
 262                                                 if (!found_libc_mmap)
 263                                                         found_libc_mmap = !strncmp(bname + 1, "libc", 4);
 264                                                 if (!found_ld_mmap)
 265                                                         found_ld_mmap = !strncmp(bname + 1, "ld", 2);
 266                                         } else if (!found_vdso_mmap)
 267                                                 found_vdso_mmap = !strcmp(mmap_filename, "[vdso]");
 268                                         break;
 269 
 270                                 case PERF_RECORD_SAMPLE:
 271                                         /* Just ignore samples for now */
 272                                         break;
 273                                 default:
 274                                         pr_debug("Unexpected perf_event->header.type %d!\n",
 275                                                  type);
 276                                         ++errs;
 277                                 }
 278 
 279                                 perf_mmap__consume(md);
 280                         }
 281                         perf_mmap__read_done(md);
 282                 }
 283 
 284                 /*
 285                  * We don't use poll here because at least at 3.1 times the
 286                  * PERF_RECORD_{!SAMPLE} events don't honour
 287                  * perf_event_attr.wakeup_events, just PERF_EVENT_SAMPLE does.
 288                  */
 289                 if (total_events == before && false)
 290                         evlist__poll(evlist, -1);
 291 
 292                 sleep(1);
 293                 if (++wakeups > 5) {
 294                         pr_debug("No PERF_RECORD_EXIT event!\n");
 295                         break;
 296                 }
 297         }
 298 
 299 found_exit:
 300         if (nr_events[PERF_RECORD_COMM] > 1 + !!found_coreutils_mmap) {
 301                 pr_debug("Excessive number of PERF_RECORD_COMM events!\n");
 302                 ++errs;
 303         }
 304 
 305         if (nr_events[PERF_RECORD_COMM] == 0) {
 306                 pr_debug("Missing PERF_RECORD_COMM for %s!\n", cmd);
 307                 ++errs;
 308         }
 309 
 310         if (!found_cmd_mmap && !found_coreutils_mmap) {
 311                 pr_debug("PERF_RECORD_MMAP for %s missing!\n", cmd);
 312                 ++errs;
 313         }
 314 
 315         if (!found_libc_mmap) {
 316                 pr_debug("PERF_RECORD_MMAP for %s missing!\n", "libc");
 317                 ++errs;
 318         }
 319 
 320         if (!found_ld_mmap) {
 321                 pr_debug("PERF_RECORD_MMAP for %s missing!\n", "ld");
 322                 ++errs;
 323         }
 324 
 325         if (!found_vdso_mmap) {
 326                 pr_debug("PERF_RECORD_MMAP for %s missing!\n", "[vdso]");
 327                 ++errs;
 328         }
 329 out_delete_evlist:
 330         evlist__delete(evlist);
 331 out:
 332         return (err < 0 || errs > 0) ? -1 : 0;
 333 }