sys/kern/kern_ktr.c

   1 /*
   2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   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  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. 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  * 3. Neither the name of The DragonFly Project 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
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /*
  35  * The following copyright applies to the DDB command code:
  36  *
  37  * Copyright (c) 2000 John Baldwin <jhb@FreeBSD.org>
  38  * All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. Neither the name of the author nor the names of any co-contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  */
  64
  65 /*
  66  * Kernel tracepoint facility.
  67  */
  68
  69 #include "opt_ddb.h"
  70 #include "opt_ktr.h"
  71
  72 #include <sys/param.h>
  73 #include <sys/cons.h>
  74 #include <sys/kernel.h>
  75 #include <sys/libkern.h>
  76 #include <sys/proc.h>
  77 #include <sys/sysctl.h>
  78 #include <sys/ktr.h>
  79 #include <sys/systm.h>
  80 #include <sys/time.h>
  81 #include <sys/malloc.h>
  82 #include <sys/spinlock.h>
  83 #include <sys/thread2.h>
  84 #include <sys/spinlock2.h>
  85 #include <sys/ctype.h>
  86
  87 #include <machine/cpu.h>
  88 #include <machine/cpufunc.h>
  89 #include <machine/specialreg.h>
  90 #include <machine/md_var.h>
  91
  92 #include <ddb/ddb.h>
  93
  94 #ifndef KTR_ENTRIES
  95 #define KTR_ENTRIES             2048
  96 #elif (KTR_ENTRIES & KTR_ENTRIES - 1)
  97 #error KTR_ENTRIES must be a power of two
  98 #endif
  99 #define KTR_ENTRIES_MASK        (KTR_ENTRIES - 1)
 100
 101 /*
 102  * test logging support.  When ktr_testlogcnt is non-zero each synchronization
 103  * interrupt will issue six back-to-back ktr logging messages on cpu 0
 104  * so the user can determine KTR logging overheads.
 105  */
 106 #if !defined(KTR_TESTLOG)
 107 #define KTR_TESTLOG     KTR_ALL
 108 #endif
 109 KTR_INFO_MASTER(testlog);
 110 #if KTR_TESTLOG
 111 KTR_INFO(KTR_TESTLOG, testlog, test1, 0, "test1 %d %d %d %d", int dummy1, int dummy2, int dummy3, int dummy4);
 112 KTR_INFO(KTR_TESTLOG, testlog, test2, 1, "test2 %d %d %d %d", int dummy1, int dummy2, int dummy3, int dummy4);
 113 KTR_INFO(KTR_TESTLOG, testlog, test3, 2, "test3 %d %d %d %d", int dummy1, int dummy2, int dummy3, int dummy4);
 114 KTR_INFO(KTR_TESTLOG, testlog, test4, 3, "test4");
 115 KTR_INFO(KTR_TESTLOG, testlog, test5, 4, "test5");
 116 KTR_INFO(KTR_TESTLOG, testlog, test6, 5, "test6");
 117 KTR_INFO(KTR_TESTLOG, testlog, pingpong, 6, "pingpong");
 118 KTR_INFO(KTR_TESTLOG, testlog, pipeline, 7, "pipeline");
 119 KTR_INFO(KTR_TESTLOG, testlog, crit_beg, 8, "crit_beg");
 120 KTR_INFO(KTR_TESTLOG, testlog, crit_end, 9, "crit_end");
 121 KTR_INFO(KTR_TESTLOG, testlog, spin_beg, 10, "spin_beg");
 122 KTR_INFO(KTR_TESTLOG, testlog, spin_end, 11, "spin_end");
 123 #define logtest(name)   KTR_LOG(testlog_ ## name, 0, 0, 0, 0)
 124 #define logtest_noargs(name)    KTR_LOG(testlog_ ## name)
 125 #endif
 126
 127 MALLOC_DEFINE(M_KTR, "ktr", "ktr buffers");
 128
 129 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RW, 0, "ktr");
 130
 131 int             ktr_entries = KTR_ENTRIES;
 132 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0,
 133     "Size of the event buffer");
 134
 135 int             ktr_version = KTR_VERSION;
 136 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
 137
 138 static int      ktr_stacktrace = 1;
 139 SYSCTL_INT(_debug_ktr, OID_AUTO, stacktrace, CTLFLAG_RD, &ktr_stacktrace, 0, "");
 140
 141 static int      ktr_resynchronize = 0;
 142 SYSCTL_INT(_debug_ktr, OID_AUTO, resynchronize, CTLFLAG_RW,
 143     &ktr_resynchronize, 0, "Resynchronize TSC 10 times a second");
 144
 145 #if KTR_TESTLOG
 146 static int      ktr_testlogcnt = 0;
 147 SYSCTL_INT(_debug_ktr, OID_AUTO, testlogcnt, CTLFLAG_RW, &ktr_testlogcnt, 0, "");
 148 static int      ktr_testipicnt = 0;
 149 static int      ktr_testipicnt_remainder;
 150 SYSCTL_INT(_debug_ktr, OID_AUTO, testipicnt, CTLFLAG_RW, &ktr_testipicnt, 0, "");
 151 static int      ktr_testcritcnt = 0;
 152 SYSCTL_INT(_debug_ktr, OID_AUTO, testcritcnt, CTLFLAG_RW, &ktr_testcritcnt, 0, "");
 153 static int      ktr_testspincnt = 0;
 154 SYSCTL_INT(_debug_ktr, OID_AUTO, testspincnt, CTLFLAG_RW, &ktr_testspincnt, 0, "");
 155 #endif
 156
 157 /*
 158  * Give cpu0 a static buffer so the tracepoint facility can be used during
 159  * early boot (note however that we still use a critical section, XXX).
 160  */
 161 static struct   ktr_entry ktr_buf0[KTR_ENTRIES];
 162
 163 struct ktr_cpu ktr_cpu[MAXCPU] = {
 164         { .core.ktr_buf = &ktr_buf0[0] }
 165 };
 166
 167 static int64_t  ktr_sync_tsc;
 168 struct callout  ktr_resync_callout;
 169
 170 #ifdef KTR_VERBOSE
 171 int     ktr_verbose = KTR_VERBOSE;
 172 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
 173 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0,
 174     "Log events to the console as well");
 175 #endif
 176
 177 static void ktr_resync_callback(void *dummy __unused);
 178
 179 extern int64_t tsc_offsets[];
 180
 181 static void
 182 ktr_sysinit(void *dummy)
 183 {
 184         struct ktr_cpu_core *kcpu;
 185         int i;
 186
 187         for(i = 1; i < ncpus; ++i) {
 188                 kcpu = &ktr_cpu[i].core;
 189                 kcpu->ktr_buf = kmalloc(KTR_ENTRIES * sizeof(struct ktr_entry),
 190                                         M_KTR, M_WAITOK | M_ZERO);
 191         }
 192         callout_init_mp(&ktr_resync_callout);
 193         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 194 }
 195 SYSINIT(ktr_sysinit, SI_BOOT2_KLD, SI_ORDER_ANY, ktr_sysinit, NULL);
 196
 197 /*
 198  * Try to resynchronize the TSC's for all cpus.  This is really, really nasty.
 199  * We have to send an IPIQ message to all remote cpus, wait until they
 200  * get into their IPIQ processing code loop, then do an even stricter hard
 201  * loop to get the cpus as close to synchronized as we can to get the most
 202  * accurate reading.
 203  *
 204  * This callback occurs on cpu0.
 205  */
 206 #if KTR_TESTLOG
 207 static void ktr_pingpong_remote(void *dummy);
 208 static void ktr_pipeline_remote(void *dummy);
 209 #endif
 210
 211 #ifdef _RDTSC_SUPPORTED_
 212
 213 static void ktr_resync_remote(void *dummy);
 214
 215 /*
 216  * We use a callout callback instead of a systimer because we cannot afford
 217  * to preempt anyone to do this, or we might deadlock a spin-lock or
 218  * serializer between two cpus.
 219  */
 220 static
 221 void
 222 ktr_resync_callback(void *dummy __unused)
 223 {
 224         struct lwkt_cpusync cs;
 225 #if KTR_TESTLOG
 226         int count;
 227 #endif
 228
 229         KKASSERT(mycpu->gd_cpuid == 0);
 230
 231 #if KTR_TESTLOG
 232         /*
 233          * Test logging
 234          */
 235         if (ktr_testlogcnt) {
 236                 --ktr_testlogcnt;
 237                 cpu_disable_intr();
 238                 logtest(test1);
 239                 logtest(test2);
 240                 logtest(test3);
 241                 logtest_noargs(test4);
 242                 logtest_noargs(test5);
 243                 logtest_noargs(test6);
 244                 cpu_enable_intr();
 245         }
 246
 247         /*
 248          * Test IPI messaging
 249          */
 250         if (ktr_testipicnt && ktr_testipicnt_remainder == 0 && ncpus > 1) {
 251                 ktr_testipicnt_remainder = ktr_testipicnt;
 252                 ktr_testipicnt = 0;
 253                 lwkt_send_ipiq_bycpu(1, ktr_pingpong_remote, NULL);
 254         }
 255
 256         /*
 257          * Test critical sections
 258          */
 259         if (ktr_testcritcnt) {
 260                 crit_enter();
 261                 crit_exit();
 262                 logtest_noargs(crit_beg);
 263                 for (count = ktr_testcritcnt; count; --count) {
 264                         crit_enter();
 265                         crit_exit();
 266                 }
 267                 logtest_noargs(crit_end);
 268                 ktr_testcritcnt = 0;
 269         }
 270
 271         /*
 272          * Test spinlock sections
 273          */
 274         if (ktr_testspincnt) {
 275                 struct spinlock spin;
 276
 277                 spin_init(&spin);
 278                 spin_lock(&spin);
 279                 spin_unlock(&spin);
 280                 logtest_noargs(spin_beg);
 281                 for (count = ktr_testspincnt; count; --count) {
 282                         spin_lock(&spin);
 283                         spin_unlock(&spin);
 284                 }
 285                 logtest_noargs(spin_end);
 286                 ktr_testspincnt = 0;
 287         }
 288 #endif
 289
 290         /*
 291          * Resynchronize the TSC
 292          */
 293         if (ktr_resynchronize == 0)
 294                 goto done;
 295         if ((cpu_feature & CPUID_TSC) == 0)
 296                 return;
 297
 298         crit_enter();
 299         lwkt_cpusync_init(&cs, smp_active_mask, ktr_resync_remote,
 300                           (void *)(intptr_t)mycpu->gd_cpuid);
 301         lwkt_cpusync_interlock(&cs);
 302         ktr_sync_tsc = rdtsc();
 303         lwkt_cpusync_deinterlock(&cs);
 304         crit_exit();
 305 done:
 306         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 307 }
 308
 309 /*
 310  * The remote-end of the KTR synchronization protocol runs on all cpus.
 311  * The one we run on the controlling cpu updates its tsc continuously
 312  * until the others have finished syncing (theoretically), but we don't
 313  * loop forever.
 314  *
 315  * This is a bit ad-hoc but we need to avoid livelocking inside an IPI
 316  * callback.  rdtsc() is a synchronizing instruction (I think).
 317  */
 318 static void
 319 ktr_resync_remote(void *arg)
 320 {
 321         globaldata_t gd = mycpu;
 322         int64_t delta;
 323         int i;
 324
 325         if (gd->gd_cpuid == (int)(intptr_t)arg) {
 326                 for (i = 0; i < 2000; ++i)
 327                         ktr_sync_tsc = rdtsc();
 328         } else {
 329                 delta = rdtsc() - ktr_sync_tsc;
 330                 if (tsc_offsets[gd->gd_cpuid] == 0)
 331                         tsc_offsets[gd->gd_cpuid] = delta;
 332                 tsc_offsets[gd->gd_cpuid] =
 333                         (tsc_offsets[gd->gd_cpuid] * 7 + delta) / 8;
 334         }
 335 }
 336
 337 #if KTR_TESTLOG
 338
 339 static
 340 void
 341 ktr_pingpong_remote(void *dummy __unused)
 342 {
 343         int other_cpu;
 344
 345         logtest_noargs(pingpong);
 346         other_cpu = 1 - mycpu->gd_cpuid;
 347         if (ktr_testipicnt_remainder) {
 348                 --ktr_testipicnt_remainder;
 349                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pingpong_remote, NULL);
 350         } else {
 351                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 352                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 353                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 354                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 355                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 356         }
 357 }
 358
 359 static
 360 void
 361 ktr_pipeline_remote(void *dummy __unused)
 362 {
 363         logtest_noargs(pipeline);
 364 }
 365
 366 #endif
 367
 368 #else   /* !_RDTSC_SUPPORTED_ */
 369
 370 /*
 371  * The resync callback for UP doesn't do anything other then run the test
 372  * log messages.  If test logging is not enabled, don't bother resetting
 373  * the callout.
 374  */
 375 static
 376 void
 377 ktr_resync_callback(void *dummy __unused)
 378 {
 379 #if KTR_TESTLOG
 380         /*
 381          * Test logging
 382          */
 383         if (ktr_testlogcnt) {
 384                 --ktr_testlogcnt;
 385                 cpu_disable_intr();
 386                 logtest(test1);
 387                 logtest(test2);
 388                 logtest(test3);
 389                 logtest_noargs(test4);
 390                 logtest_noargs(test5);
 391                 logtest_noargs(test6);
 392                 cpu_enable_intr();
 393         }
 394         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 395 #endif
 396 }
 397
 398 #endif
 399
 400 /*
 401  * Setup the next empty slot and return it to the caller to store the data
 402  * directly.
 403  */
 404 struct ktr_entry *
 405 ktr_begin_write_entry(struct ktr_info *info, const char *file, int line)
 406 {
 407         struct ktr_cpu_core *kcpu;
 408         struct ktr_entry *entry;
 409         int cpu;
 410
 411         cpu = mycpu->gd_cpuid;
 412         kcpu = &ktr_cpu[cpu].core;
 413         if (panicstr)                   /* stop logging during panic */
 414                 return NULL;
 415         if (kcpu->ktr_buf == NULL)      /* too early in boot */
 416                 return NULL;
 417
 418         crit_enter();
 419         entry = kcpu->ktr_buf + (kcpu->ktr_idx & KTR_ENTRIES_MASK);
 420         ++kcpu->ktr_idx;
 421 #ifdef _RDTSC_SUPPORTED_
 422         if (cpu_feature & CPUID_TSC) {
 423                 entry->ktr_timestamp = rdtsc() - tsc_offsets[cpu];
 424         } else
 425 #endif
 426         {
 427                 entry->ktr_timestamp = get_approximate_time_t();
 428         }
 429         entry->ktr_info = info;
 430         entry->ktr_file = file;
 431         entry->ktr_line = line;
 432         crit_exit();
 433         return entry;
 434 }
 435
 436 int
 437 ktr_finish_write_entry(struct ktr_info *info, struct ktr_entry *entry)
 438 {
 439         if (ktr_stacktrace)
 440                 cpu_ktr_caller(entry);
 441 #ifdef KTR_VERBOSE
 442         if (ktr_verbose && info->kf_format) {
 443                 kprintf("cpu%d ", mycpu->gd_cpuid);
 444                 if (ktr_verbose > 1) {
 445                         kprintf("%s.%d\t", entry->ktr_file, entry->ktr_line);
 446                 }
 447                 return !0;
 448         }
 449 #endif
 450         return 0;
 451 }
 452
 453 #ifdef DDB
 454
 455 #define NUM_LINES_PER_PAGE      19
 456
 457 struct tstate {
 458         int     cur;
 459         int     first;
 460 };
 461
 462 static  int db_ktr_verbose;
 463 static  int db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx);
 464
 465 DB_SHOW_COMMAND(ktr, db_ktr_all)
 466 {
 467         struct ktr_cpu_core *kcpu;
 468         int a_flag = 0;
 469         int c;
 470         int nl = 0;
 471         int i;
 472         struct tstate tstate[MAXCPU];
 473         int printcpu = -1;
 474
 475         for(i = 0; i < ncpus; i++) {
 476                 kcpu = &ktr_cpu[i].core;
 477                 tstate[i].first = -1;
 478                 tstate[i].cur = (kcpu->ktr_idx - 1) & KTR_ENTRIES_MASK;
 479         }
 480         db_ktr_verbose = 0;
 481         while ((c = *(modif++)) != '\0') {
 482                 if (c == 'v') {
 483                         db_ktr_verbose = 1;
 484                 }
 485                 else if (c == 'a') {
 486                         a_flag = 1;
 487                 }
 488                 else if (c == 'c') {
 489                         printcpu = 0;
 490                         while ((c = *(modif++)) != '\0') {
 491                                 if (isdigit(c)) {
 492                                         printcpu *= 10;
 493                                         printcpu += c - '0';
 494                                 }
 495                                 else {
 496                                         modif++;
 497                                         break;
 498                                 }
 499                         }
 500                         modif--;
 501                 }
 502         }
 503         if (printcpu > ncpus - 1) {
 504                 db_printf("Invalid cpu number\n");
 505                 return;
 506         }
 507         /*
 508          * Lopp throug all the buffers and print the content of them, sorted
 509          * by the timestamp.
 510          */
 511         while (1) {
 512                 int counter;
 513                 u_int64_t highest_ts;
 514                 int highest_cpu;
 515                 struct ktr_entry *kp;
 516
 517                 if (a_flag == 1 && cncheckc() != -1)
 518                         return;
 519                 highest_ts = 0;
 520                 highest_cpu = -1;
 521                 /*
 522                  * Find the lowest timestamp
 523                  */
 524                 for (i = 0, counter = 0; i < ncpus; i++) {
 525                         kcpu = &ktr_cpu[i].core;
 526                         if (kcpu->ktr_buf == NULL)
 527                                 continue;
 528                         if (printcpu != -1 && printcpu != i)
 529                                 continue;
 530                         if (tstate[i].cur == -1) {
 531                                 counter++;
 532                                 if (counter == ncpus) {
 533                                         db_printf("--- End of trace buffer ---\n");
 534                                         return;
 535                                 }
 536                                 continue;
 537                         }
 538                         if (kcpu->ktr_buf[tstate[i].cur].ktr_timestamp > highest_ts) {
 539                                 highest_ts = kcpu->ktr_buf[tstate[i].cur].ktr_timestamp;
 540                                 highest_cpu = i;
 541                         }
 542                 }
 543                 if (highest_cpu < 0) {
 544                         db_printf("no KTR data available\n");
 545                         break;
 546                 }
 547                 i = highest_cpu;
 548                 kcpu = &ktr_cpu[i].core;
 549                 kp = &kcpu->ktr_buf[tstate[i].cur];
 550                 if (tstate[i].first == -1)
 551                         tstate[i].first = tstate[i].cur;
 552                 if (--tstate[i].cur < 0)
 553                         tstate[i].cur = KTR_ENTRIES - 1;
 554                 if (tstate[i].first == tstate[i].cur) {
 555                         db_mach_vtrace(i, kp, tstate[i].cur + 1);
 556                         tstate[i].cur = -1;
 557                         continue;
 558                 }
 559                 if (kcpu->ktr_buf[tstate[i].cur].ktr_info == NULL)
 560                         tstate[i].cur = -1;
 561                 if (db_more(&nl) == -1)
 562                         break;
 563                 if (db_mach_vtrace(i, kp, tstate[i].cur + 1) == 0)
 564                         tstate[i].cur = -1;
 565         }
 566 }
 567
 568 static int
 569 db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx)
 570 {
 571         if (kp->ktr_info == NULL)
 572                 return(0);
 573         db_printf("cpu%d ", cpu);
 574         db_printf("%d: ", idx);
 575         if (db_ktr_verbose) {
 576                 db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
 577                     kp->ktr_file, kp->ktr_line);
 578         }
 579         db_printf("%s\t", kp->ktr_info->kf_name);
 580         db_printf("from(%p,%p) ", kp->ktr_caller1, kp->ktr_caller2);
 581 #ifdef __i386__
 582         if (kp->ktr_info->kf_format)
 583                 db_vprintf(kp->ktr_info->kf_format, (__va_list)kp->ktr_data);
 584 #endif
 585         db_printf("\n");
 586
 587         return(1);
 588 }
 589
 590 #endif  /* DDB */