sys/cddl/dev/profile/profile.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  *
  21  * Portions Copyright 2006-2008 John Birrell jb@freebsd.org
  22  *
  23  * $FreeBSD$
  24  *
  25  */
  26
  27 /*
  28  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  29  * Use is subject to license terms.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/conf.h>
  36 #include <sys/cpuvar.h>
  37 #include <sys/fcntl.h>
  38 #include <sys/filio.h>
  39 #include <sys/kdb.h>
  40 #include <sys/kernel.h>
  41 #include <sys/kmem.h>
  42 #include <sys/kthread.h>
  43 #include <sys/limits.h>
  44 #include <sys/linker.h>
  45 #include <sys/lock.h>
  46 #include <sys/malloc.h>
  47 #include <sys/module.h>
  48 #include <sys/mutex.h>
  49 #include <sys/poll.h>
  50 #include <sys/proc.h>
  51 #include <sys/selinfo.h>
  52 #include <sys/smp.h>
  53 #include <sys/uio.h>
  54 #include <sys/unistd.h>
  55 #include <machine/stdarg.h>
  56
  57 #include <sys/cyclic.h>
  58 #include <sys/dtrace.h>
  59 #include <sys/dtrace_bsd.h>
  60
  61 #define PROF_NAMELEN            15
  62
  63 #define PROF_PROFILE            0
  64 #define PROF_TICK               1
  65 #define PROF_PREFIX_PROFILE     "profile-"
  66 #define PROF_PREFIX_TICK        "tick-"
  67
  68 /*
  69  * Regardless of platform, there are five artificial frames in the case of the
  70  * profile provider:
  71  *
  72  *      profile_fire
  73  *      cyclic_expire
  74  *      cyclic_fire
  75  *      [ cbe ]
  76  *      [ locore ]
  77  *
  78  * On amd64, there are two frames associated with locore:  one in locore, and
  79  * another in common interrupt dispatch code.  (i386 has not been modified to
  80  * use this common layer.)  Further, on i386, the interrupted instruction
  81  * appears as its own stack frame.  All of this means that we need to add one
  82  * frame for amd64, and then take one away for both amd64 and i386.
  83  *
  84  * On SPARC, the picture is further complicated because the compiler
  85  * optimizes away tail-calls -- so the following frames are optimized away:
  86  *
  87  *      profile_fire
  88  *      cyclic_expire
  89  *
  90  * This gives three frames.  However, on DEBUG kernels, the cyclic_expire
  91  * frame cannot be tail-call eliminated, yielding four frames in this case.
  92  *
  93  * All of the above constraints lead to the mess below.  Yes, the profile
  94  * provider should ideally figure this out on-the-fly by hiting one of its own
  95  * probes and then walking its own stack trace.  This is complicated, however,
  96  * and the static definition doesn't seem to be overly brittle.  Still, we
  97  * allow for a manual override in case we get it completely wrong.
  98  */
  99 #ifdef __amd64
 100 #define PROF_ARTIFICIAL_FRAMES  7
 101 #else
 102 #ifdef __i386
 103 #define PROF_ARTIFICIAL_FRAMES  6
 104 #else
 105 #ifdef __sparc
 106 #ifdef DEBUG
 107 #define PROF_ARTIFICIAL_FRAMES  4
 108 #else
 109 #define PROF_ARTIFICIAL_FRAMES  3
 110 #endif
 111 #endif
 112 #endif
 113 #endif
 114
 115 #ifdef __mips
 116 /*
 117  * This value is bogus just to make module compilable on mips
 118  */
 119 #define PROF_ARTIFICIAL_FRAMES  3
 120 #endif
 121
 122 #ifdef __powerpc__
 123 /*
 124  * This value is bogus just to make module compilable on powerpc
 125  */
 126 #define PROF_ARTIFICIAL_FRAMES  3
 127 #endif
 128
 129 typedef struct profile_probe {
 130         char            prof_name[PROF_NAMELEN];
 131         dtrace_id_t     prof_id;
 132         int             prof_kind;
 133         hrtime_t        prof_interval;
 134         cyclic_id_t     prof_cyclic;
 135 } profile_probe_t;
 136
 137 typedef struct profile_probe_percpu {
 138         hrtime_t        profc_expected;
 139         hrtime_t        profc_interval;
 140         profile_probe_t *profc_probe;
 141 } profile_probe_percpu_t;
 142
 143 static d_open_t profile_open;
 144 static int      profile_unload(void);
 145 static void     profile_create(hrtime_t, char *, int);
 146 static void     profile_destroy(void *, dtrace_id_t, void *);
 147 static void     profile_enable(void *, dtrace_id_t, void *);
 148 static void     profile_disable(void *, dtrace_id_t, void *);
 149 static void     profile_load(void *);
 150 static void     profile_provide(void *, dtrace_probedesc_t *);
 151
 152 static int profile_rates[] = {
 153     97, 199, 499, 997, 1999,
 154     4001, 4999, 0, 0, 0,
 155     0, 0, 0, 0, 0,
 156     0, 0, 0, 0, 0
 157 };
 158
 159 static int profile_ticks[] = {
 160     1, 10, 100, 500, 1000,
 161     5000, 0, 0, 0, 0,
 162     0, 0, 0, 0, 0
 163 };
 164
 165 /*
 166  * profile_max defines the upper bound on the number of profile probes that
 167  * can exist (this is to prevent malicious or clumsy users from exhausing
 168  * system resources by creating a slew of profile probes). At mod load time,
 169  * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
 170  * present in the profile.conf file.
 171  */
 172 #define PROFILE_MAX_DEFAULT     1000    /* default max. number of probes */
 173 static uint32_t profile_max = PROFILE_MAX_DEFAULT;
 174                                         /* maximum number of profile probes */
 175 static uint32_t profile_total;          /* current number of profile probes */
 176
 177 static struct cdevsw profile_cdevsw = {
 178         .d_version      = D_VERSION,
 179         .d_open         = profile_open,
 180         .d_name         = "profile",
 181 };
 182
 183 static dtrace_pattr_t profile_attr = {
 184 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 185 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 186 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
 187 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 188 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
 189 };
 190
 191 static dtrace_pops_t profile_pops = {
 192         profile_provide,
 193         NULL,
 194         profile_enable,
 195         profile_disable,
 196         NULL,
 197         NULL,
 198         NULL,
 199         NULL,
 200         NULL,
 201         profile_destroy
 202 };
 203
 204 static struct cdev              *profile_cdev;
 205 static dtrace_provider_id_t     profile_id;
 206 static hrtime_t                 profile_interval_min = NANOSEC / 5000;  /* 5000 hz */
 207 static int                      profile_aframes = 0;                    /* override */
 208
 209 static void
 210 profile_fire(void *arg)
 211 {
 212         profile_probe_percpu_t *pcpu = arg;
 213         profile_probe_t *prof = pcpu->profc_probe;
 214         hrtime_t late;
 215         solaris_cpu_t *c = &solaris_cpu[curcpu];
 216
 217         late = gethrtime() - pcpu->profc_expected;
 218         pcpu->profc_expected += pcpu->profc_interval;
 219
 220         dtrace_probe(prof->prof_id, c->cpu_profile_pc,
 221             c->cpu_profile_upc, late, 0, 0);
 222 }
 223
 224 static void
 225 profile_tick(void *arg)
 226 {
 227         profile_probe_t *prof = arg;
 228         solaris_cpu_t *c = &solaris_cpu[curcpu];
 229
 230         dtrace_probe(prof->prof_id, c->cpu_profile_pc,
 231             c->cpu_profile_upc, 0, 0, 0);
 232 }
 233
 234 static void
 235 profile_create(hrtime_t interval, char *name, int kind)
 236 {
 237         profile_probe_t *prof;
 238
 239         if (interval < profile_interval_min)
 240                 return;
 241
 242         if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
 243                 return;
 244
 245         atomic_add_32(&profile_total, 1);
 246         if (profile_total > profile_max) {
 247                 atomic_add_32(&profile_total, -1);
 248                 return;
 249         }
 250
 251         prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
 252         (void) strcpy(prof->prof_name, name);
 253         prof->prof_interval = interval;
 254         prof->prof_cyclic = CYCLIC_NONE;
 255         prof->prof_kind = kind;
 256         prof->prof_id = dtrace_probe_create(profile_id,
 257             NULL, NULL, name,
 258             profile_aframes ? profile_aframes : PROF_ARTIFICIAL_FRAMES, prof);
 259 }
 260
 261 /*ARGSUSED*/
 262 static void
 263 profile_provide(void *arg, dtrace_probedesc_t *desc)
 264 {
 265         int i, j, rate, kind;
 266         hrtime_t val = 0, mult = 1, len = 0;
 267         char *name, *suffix = NULL;
 268
 269         const struct {
 270                 char *prefix;
 271                 int kind;
 272         } types[] = {
 273                 { PROF_PREFIX_PROFILE, PROF_PROFILE },
 274                 { PROF_PREFIX_TICK, PROF_TICK },
 275                 { 0, 0 }
 276         };
 277
 278         const struct {
 279                 char *name;
 280                 hrtime_t mult;
 281         } suffixes[] = {
 282                 { "ns",         NANOSEC / NANOSEC },
 283                 { "nsec",       NANOSEC / NANOSEC },
 284                 { "us",         NANOSEC / MICROSEC },
 285                 { "usec",       NANOSEC / MICROSEC },
 286                 { "ms",         NANOSEC / MILLISEC },
 287                 { "msec",       NANOSEC / MILLISEC },
 288                 { "s",          NANOSEC / SEC },
 289                 { "sec",        NANOSEC / SEC },
 290                 { "m",          NANOSEC * (hrtime_t)60 },
 291                 { "min",        NANOSEC * (hrtime_t)60 },
 292                 { "h",          NANOSEC * (hrtime_t)(60 * 60) },
 293                 { "hour",       NANOSEC * (hrtime_t)(60 * 60) },
 294                 { "d",          NANOSEC * (hrtime_t)(24 * 60 * 60) },
 295                 { "day",        NANOSEC * (hrtime_t)(24 * 60 * 60) },
 296                 { "hz",         0 },
 297                 { NULL }
 298         };
 299
 300         if (desc == NULL) {
 301                 char n[PROF_NAMELEN];
 302
 303                 /*
 304                  * If no description was provided, provide all of our probes.
 305                  */
 306                 for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) {
 307                         if ((rate = profile_rates[i]) == 0)
 308                                 continue;
 309
 310                         (void) snprintf(n, PROF_NAMELEN, "%s%d",
 311                             PROF_PREFIX_PROFILE, rate);
 312                         profile_create(NANOSEC / rate, n, PROF_PROFILE);
 313                 }
 314
 315                 for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) {
 316                         if ((rate = profile_ticks[i]) == 0)
 317                                 continue;
 318
 319                         (void) snprintf(n, PROF_NAMELEN, "%s%d",
 320                             PROF_PREFIX_TICK, rate);
 321                         profile_create(NANOSEC / rate, n, PROF_TICK);
 322                 }
 323
 324                 return;
 325         }
 326
 327         name = desc->dtpd_name;
 328
 329         for (i = 0; types[i].prefix != NULL; i++) {
 330                 len = strlen(types[i].prefix);
 331
 332                 if (strncmp(name, types[i].prefix, len) != 0)
 333                         continue;
 334                 break;
 335         }
 336
 337         if (types[i].prefix == NULL)
 338                 return;
 339
 340         kind = types[i].kind;
 341         j = strlen(name) - len;
 342
 343         /*
 344          * We need to start before any time suffix.
 345          */
 346         for (j = strlen(name); j >= len; j--) {
 347                 if (name[j] >= '0' && name[j] <= '9')
 348                         break;
 349                 suffix = &name[j];
 350         }
 351
 352         ASSERT(suffix != NULL);
 353
 354         /*
 355          * Now determine the numerical value present in the probe name.
 356          */
 357         for (; j >= len; j--) {
 358                 if (name[j] < '0' || name[j] > '9')
 359                         return;
 360
 361                 val += (name[j] - '0') * mult;
 362                 mult *= (hrtime_t)10;
 363         }
 364
 365         if (val == 0)
 366                 return;
 367
 368         /*
 369          * Look-up the suffix to determine the multiplier.
 370          */
 371         for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
 372                 if (strcasecmp(suffixes[i].name, suffix) == 0) {
 373                         mult = suffixes[i].mult;
 374                         break;
 375                 }
 376         }
 377
 378         if (suffixes[i].name == NULL && *suffix != '\0')
 379                 return;
 380
 381         if (mult == 0) {
 382                 /*
 383                  * The default is frequency-per-second.
 384                  */
 385                 val = NANOSEC / val;
 386         } else {
 387                 val *= mult;
 388         }
 389
 390         profile_create(val, name, kind);
 391 }
 392
 393 /* ARGSUSED */
 394 static void
 395 profile_destroy(void *arg, dtrace_id_t id, void *parg)
 396 {
 397         profile_probe_t *prof = parg;
 398
 399         ASSERT(prof->prof_cyclic == CYCLIC_NONE);
 400         kmem_free(prof, sizeof (profile_probe_t));
 401
 402         ASSERT(profile_total >= 1);
 403         atomic_add_32(&profile_total, -1);
 404 }
 405
 406 /*ARGSUSED*/
 407 static void
 408 profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
 409 {
 410         profile_probe_t *prof = arg;
 411         profile_probe_percpu_t *pcpu;
 412
 413         pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP);
 414         pcpu->profc_probe = prof;
 415
 416         hdlr->cyh_func = profile_fire;
 417         hdlr->cyh_arg = pcpu;
 418
 419         when->cyt_interval = prof->prof_interval;
 420         when->cyt_when = gethrtime() + when->cyt_interval;
 421
 422         pcpu->profc_expected = when->cyt_when;
 423         pcpu->profc_interval = when->cyt_interval;
 424 }
 425
 426 /*ARGSUSED*/
 427 static void
 428 profile_offline(void *arg, cpu_t *cpu, void *oarg)
 429 {
 430         profile_probe_percpu_t *pcpu = oarg;
 431
 432         ASSERT(pcpu->profc_probe == arg);
 433         kmem_free(pcpu, sizeof (profile_probe_percpu_t));
 434 }
 435
 436 /* ARGSUSED */
 437 static void
 438 profile_enable(void *arg, dtrace_id_t id, void *parg)
 439 {
 440         profile_probe_t *prof = parg;
 441         cyc_omni_handler_t omni;
 442         cyc_handler_t hdlr;
 443         cyc_time_t when;
 444
 445         ASSERT(prof->prof_interval != 0);
 446         ASSERT(MUTEX_HELD(&cpu_lock));
 447
 448         if (prof->prof_kind == PROF_TICK) {
 449                 hdlr.cyh_func = profile_tick;
 450                 hdlr.cyh_arg = prof;
 451
 452                 when.cyt_interval = prof->prof_interval;
 453                 when.cyt_when = gethrtime() + when.cyt_interval;
 454         } else {
 455                 ASSERT(prof->prof_kind == PROF_PROFILE);
 456                 omni.cyo_online = profile_online;
 457                 omni.cyo_offline = profile_offline;
 458                 omni.cyo_arg = prof;
 459         }
 460
 461         if (prof->prof_kind == PROF_TICK) {
 462                 prof->prof_cyclic = cyclic_add(&hdlr, &when);
 463         } else {
 464                 prof->prof_cyclic = cyclic_add_omni(&omni);
 465         }
 466 }
 467
 468 /* ARGSUSED */
 469 static void
 470 profile_disable(void *arg, dtrace_id_t id, void *parg)
 471 {
 472         profile_probe_t *prof = parg;
 473
 474         ASSERT(prof->prof_cyclic != CYCLIC_NONE);
 475         ASSERT(MUTEX_HELD(&cpu_lock));
 476
 477         cyclic_remove(prof->prof_cyclic);
 478         prof->prof_cyclic = CYCLIC_NONE;
 479 }
 480
 481 static void
 482 profile_load(void *dummy)
 483 {
 484         /* Create the /dev/dtrace/profile entry. */
 485         profile_cdev = make_dev(&profile_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
 486             "dtrace/profile");
 487
 488         if (dtrace_register("profile", &profile_attr, DTRACE_PRIV_USER,
 489             NULL, &profile_pops, NULL, &profile_id) != 0)
 490                 return;
 491 }
 492
 493
 494 static int
 495 profile_unload()
 496 {
 497         int error = 0;
 498
 499         if ((error = dtrace_unregister(profile_id)) != 0)
 500                 return (error);
 501
 502         destroy_dev(profile_cdev);
 503
 504         return (error);
 505 }
 506
 507 /* ARGSUSED */
 508 static int
 509 profile_modevent(module_t mod __unused, int type, void *data __unused)
 510 {
 511         int error = 0;
 512
 513         switch (type) {
 514         case MOD_LOAD:
 515                 break;
 516
 517         case MOD_UNLOAD:
 518                 break;
 519
 520         case MOD_SHUTDOWN:
 521                 break;
 522
 523         default:
 524                 error = EOPNOTSUPP;
 525                 break;
 526
 527         }
 528         return (error);
 529 }
 530
 531 /* ARGSUSED */
 532 static int
 533 profile_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
 534 {
 535         return (0);
 536 }
 537
 538 SYSINIT(profile_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_load, NULL);
 539 SYSUNINIT(profile_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_unload, NULL);
 540
 541 DEV_MODULE(profile, profile_modevent, NULL);
 542 MODULE_VERSION(profile, 1);
 543 MODULE_DEPEND(profile, dtrace, 1, 1, 1);
 544 MODULE_DEPEND(profile, cyclic, 1, 1, 1);
 545 MODULE_DEPEND(profile, opensolaris, 1, 1, 1);