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  * $DragonFly: src/sys/kern/kern_ktr.c,v 1.23 2008/02/12 23:33:23 corecode Exp $
  66  */
  67 /*
  68  * Kernel tracepoint facility.
  69  */
  70
  71 #include "opt_ddb.h"
  72 #include "opt_ktr.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/cons.h>
  76 #include <sys/kernel.h>
  77 #include <sys/libkern.h>
  78 #include <sys/proc.h>
  79 #include <sys/sysctl.h>
  80 #include <sys/ktr.h>
  81 #include <sys/systm.h>
  82 #include <sys/time.h>
  83 #include <sys/malloc.h>
  84 #include <sys/spinlock.h>
  85 #include <sys/thread2.h>
  86 #include <sys/spinlock2.h>
  87 #include <sys/ctype.h>
  88
  89 #include <machine/cpu.h>
  90 #include <machine/cpufunc.h>
  91 #include <machine/specialreg.h>
  92 #include <machine/md_var.h>
  93
  94 #include <ddb/ddb.h>
  95
  96 #ifndef KTR_ENTRIES
  97 #define KTR_ENTRIES             2048
  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", sizeof(void *) * 4);
 112 KTR_INFO(KTR_TESTLOG, testlog, test2, 1, "test2", sizeof(void *) * 4);
 113 KTR_INFO(KTR_TESTLOG, testlog, test3, 2, "test3", sizeof(void *) * 4);
 114 KTR_INFO(KTR_TESTLOG, testlog, test4, 3, "test4", 0);
 115 KTR_INFO(KTR_TESTLOG, testlog, test5, 4, "test5", 0);
 116 KTR_INFO(KTR_TESTLOG, testlog, test6, 5, "test6", 0);
 117 #ifdef SMP
 118 KTR_INFO(KTR_TESTLOG, testlog, pingpong, 6, "pingpong", 0);
 119 KTR_INFO(KTR_TESTLOG, testlog, pipeline, 7, "pipeline", 0);
 120 KTR_INFO(KTR_TESTLOG, testlog, crit_beg, 8, "crit_beg", 0);
 121 KTR_INFO(KTR_TESTLOG, testlog, crit_end, 9, "crit_end", 0);
 122 KTR_INFO(KTR_TESTLOG, testlog, spin_beg, 10, "spin_beg", 0);
 123 KTR_INFO(KTR_TESTLOG, testlog, spin_end, 11, "spin_end", 0);
 124 #endif
 125 #define logtest(name)   KTR_LOG(testlog_ ## name, 0, 0, 0, 0)
 126 #define logtest_noargs(name)    KTR_LOG(testlog_ ## name)
 127 #endif
 128
 129 MALLOC_DEFINE(M_KTR, "ktr", "ktr buffers");
 130
 131 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RW, 0, "ktr");
 132
 133 int             ktr_entries = KTR_ENTRIES;
 134 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");
 135
 136 int             ktr_version = KTR_VERSION;
 137 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
 138
 139 static int      ktr_stacktrace = 1;
 140 SYSCTL_INT(_debug_ktr, OID_AUTO, stacktrace, CTLFLAG_RD, &ktr_stacktrace, 0, "");
 141
 142 static int      ktr_resynchronize = 0;
 143 SYSCTL_INT(_debug_ktr, OID_AUTO, resynchronize, CTLFLAG_RW, &ktr_resynchronize, 0, "");
 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 #ifdef SMP
 150 static int      ktr_testipicnt_remainder;
 151 #endif
 152 SYSCTL_INT(_debug_ktr, OID_AUTO, testipicnt, CTLFLAG_RW, &ktr_testipicnt, 0, "");
 153 static int      ktr_testcritcnt = 0;
 154 SYSCTL_INT(_debug_ktr, OID_AUTO, testcritcnt, CTLFLAG_RW, &ktr_testcritcnt, 0, "");
 155 static int      ktr_testspincnt = 0;
 156 SYSCTL_INT(_debug_ktr, OID_AUTO, testspincnt, CTLFLAG_RW, &ktr_testspincnt, 0, "");
 157 #endif
 158
 159 /*
 160  * Give cpu0 a static buffer so the tracepoint facility can be used during
 161  * early boot (note however that we still use a critical section, XXX).
 162  */
 163 static struct   ktr_entry ktr_buf0[KTR_ENTRIES];
 164
 165 __cachealign struct ktr_cpu ktr_cpu[MAXCPU] = {
 166         { .core.ktr_buf = &ktr_buf0[0] }
 167 };
 168
 169 #ifdef SMP
 170 static int      ktr_sync_state = 0;
 171 static int      ktr_sync_count;
 172 static int64_t  ktr_sync_tsc;
 173 #endif
 174 struct callout  ktr_resync_callout;
 175
 176 #ifdef KTR_VERBOSE
 177 int     ktr_verbose = KTR_VERBOSE;
 178 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
 179 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
 180 #endif
 181
 182 static void ktr_resync_callback(void *dummy __unused);
 183
 184 extern int64_t tsc_offsets[];
 185
 186 static void
 187 ktr_sysinit(void *dummy)
 188 {
 189         struct ktr_cpu_core *kcpu;
 190         int i;
 191
 192         for(i = 1; i < ncpus; ++i) {
 193                 kcpu = &ktr_cpu[i].core;
 194                 kcpu->ktr_buf = kmalloc(KTR_ENTRIES * sizeof(struct ktr_entry),
 195                                         M_KTR, M_WAITOK | M_ZERO);
 196         }
 197         callout_init(&ktr_resync_callout);
 198         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 199 }
 200 SYSINIT(ktr_sysinit, SI_BOOT2_KLD, SI_ORDER_ANY, ktr_sysinit, NULL);
 201
 202 /*
 203  * Try to resynchronize the TSC's for all cpus.  This is really, really nasty.
 204  * We have to send an IPIQ message to all remote cpus, wait until they
 205  * get into their IPIQ processing code loop, then do an even stricter hard
 206  * loop to get the cpus as close to synchronized as we can to get the most
 207  * accurate reading.
 208  *
 209  * This callback occurs on cpu0.
 210  */
 211 #if KTR_TESTLOG
 212 #ifdef SMP
 213 static void ktr_pingpong_remote(void *dummy);
 214 static void ktr_pipeline_remote(void *dummy);
 215 #endif
 216 #endif
 217
 218 #if defined(SMP) && defined(_RDTSC_SUPPORTED_)
 219
 220 static void ktr_resync_remote(void *dummy);
 221 extern cpumask_t smp_active_mask;
 222
 223 /*
 224  * We use a callout callback instead of a systimer because we cannot afford
 225  * to preempt anyone to do this, or we might deadlock a spin-lock or
 226  * serializer between two cpus.
 227  */
 228 static
 229 void
 230 ktr_resync_callback(void *dummy __unused)
 231 {
 232         int count;
 233
 234         KKASSERT(mycpu->gd_cpuid == 0);
 235
 236 #if KTR_TESTLOG
 237         /*
 238          * Test logging
 239          */
 240         if (ktr_testlogcnt) {
 241                 --ktr_testlogcnt;
 242                 cpu_disable_intr();
 243                 logtest(test1);
 244                 logtest(test2);
 245                 logtest(test3);
 246                 logtest_noargs(test4);
 247                 logtest_noargs(test5);
 248                 logtest_noargs(test6);
 249                 cpu_enable_intr();
 250         }
 251
 252         /*
 253          * Test IPI messaging
 254          */
 255         if (ktr_testipicnt && ktr_testipicnt_remainder == 0 && ncpus > 1) {
 256                 ktr_testipicnt_remainder = ktr_testipicnt;
 257                 ktr_testipicnt = 0;
 258                 lwkt_send_ipiq_bycpu(1, ktr_pingpong_remote, NULL);
 259         }
 260
 261         /*
 262          * Test critical sections
 263          */
 264         if (ktr_testcritcnt) {
 265                 crit_enter();
 266                 crit_exit();
 267                 logtest_noargs(crit_beg);
 268                 for (count = ktr_testcritcnt; count; --count) {
 269                         crit_enter();
 270                         crit_exit();
 271                 }
 272                 logtest_noargs(crit_end);
 273                 ktr_testcritcnt = 0;
 274         }
 275
 276         /*
 277          * Test spinlock sections
 278          */
 279         if (ktr_testspincnt) {
 280                 struct spinlock spin;
 281
 282                 spin_init(&spin);
 283                 spin_lock_wr(&spin);
 284                 spin_unlock_wr(&spin);
 285                 logtest_noargs(spin_beg);
 286                 for (count = ktr_testspincnt; count; --count) {
 287                         spin_lock_wr(&spin);
 288                         spin_unlock_wr(&spin);
 289                 }
 290                 logtest_noargs(spin_end);
 291                 logtest_noargs(spin_beg);
 292                 for (count = ktr_testspincnt; count; --count) {
 293                         spin_lock_rd(&spin);
 294                         spin_unlock_rd(&spin);
 295                 }
 296                 logtest_noargs(spin_end);
 297                 ktr_testspincnt = 0;
 298         }
 299 #endif
 300
 301         /*
 302          * Resynchronize the TSC
 303          */
 304         if (ktr_resynchronize == 0)
 305                 goto done;
 306         if ((cpu_feature & CPUID_TSC) == 0)
 307                 return;
 308
 309         /*
 310          * Send the synchronizing IPI and wait for all cpus to get into
 311          * their spin loop.  We must process incoming IPIs while waiting
 312          * to avoid a deadlock.
 313          */
 314         crit_enter();
 315         ktr_sync_count = 0;
 316         ktr_sync_state = 1;
 317         ktr_sync_tsc = rdtsc();
 318         count = lwkt_send_ipiq_mask(mycpu->gd_other_cpus & smp_active_mask,
 319                                     (ipifunc1_t)ktr_resync_remote, NULL);
 320         while (ktr_sync_count != count)
 321                 lwkt_process_ipiq();
 322
 323         /*
 324          * Continuously update the TSC for cpu 0 while waiting for all other
 325          * cpus to finish stage 2.
 326          */
 327         cpu_disable_intr();
 328         ktr_sync_tsc = rdtsc();
 329         cpu_sfence();
 330         ktr_sync_state = 2;
 331         cpu_sfence();
 332         while (ktr_sync_count != 0) {
 333                 ktr_sync_tsc = rdtsc();
 334                 cpu_lfence();
 335                 cpu_nop();
 336         }
 337         cpu_enable_intr();
 338         crit_exit();
 339         ktr_sync_state = 0;
 340 done:
 341         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 342 }
 343
 344 /*
 345  * The remote-end of the KTR synchronization protocol runs on all cpus except
 346  * cpu 0.  Since this is an IPI function, it is entered with the current
 347  * thread in a critical section.
 348  */
 349 static void
 350 ktr_resync_remote(void *dummy __unused)
 351 {
 352         volatile int64_t tsc1 = ktr_sync_tsc;
 353         volatile int64_t tsc2;
 354
 355         /*
 356          * Inform the master that we have entered our hard loop.
 357          */
 358         KKASSERT(ktr_sync_state == 1);
 359         atomic_add_int(&ktr_sync_count, 1);
 360         while (ktr_sync_state == 1) {
 361                 lwkt_process_ipiq();
 362         }
 363
 364         /*
 365          * Now the master is in a hard loop, synchronize the TSC and
 366          * we are done.
 367          */
 368         cpu_disable_intr();
 369         KKASSERT(ktr_sync_state == 2);
 370         tsc2 = ktr_sync_tsc;
 371         if (tsc2 > tsc1)
 372                 tsc_offsets[mycpu->gd_cpuid] = rdtsc() - tsc2;
 373         atomic_subtract_int(&ktr_sync_count, 1);
 374         cpu_enable_intr();
 375 }
 376
 377 #if KTR_TESTLOG
 378
 379 static
 380 void
 381 ktr_pingpong_remote(void *dummy __unused)
 382 {
 383         int other_cpu;
 384
 385         logtest_noargs(pingpong);
 386         other_cpu = 1 - mycpu->gd_cpuid;
 387         if (ktr_testipicnt_remainder) {
 388                 --ktr_testipicnt_remainder;
 389                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pingpong_remote, NULL);
 390         } else {
 391                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 392                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 393                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 394                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 395                 lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
 396         }
 397 }
 398
 399 static
 400 void
 401 ktr_pipeline_remote(void *dummy __unused)
 402 {
 403         logtest_noargs(pipeline);
 404 }
 405
 406 #endif
 407
 408 #else   /* !SMP */
 409
 410 /*
 411  * The resync callback for UP doesn't do anything other then run the test
 412  * log messages.  If test logging is not enabled, don't bother resetting
 413  * the callout.
 414  */
 415 static
 416 void
 417 ktr_resync_callback(void *dummy __unused)
 418 {
 419 #if KTR_TESTLOG
 420         /*
 421          * Test logging
 422          */
 423         if (ktr_testlogcnt) {
 424                 --ktr_testlogcnt;
 425                 cpu_disable_intr();
 426                 logtest(test1);
 427                 logtest(test2);
 428                 logtest(test3);
 429                 logtest_noargs(test4);
 430                 logtest_noargs(test5);
 431                 logtest_noargs(test6);
 432                 cpu_enable_intr();
 433         }
 434         callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
 435 #endif
 436 }
 437
 438 #endif
 439
 440 /*
 441  * KTR_WRITE_ENTRY - Primary entry point for kernel trace logging
 442  */
 443
 444 static __inline
 445 void
 446 ktr_write_entry(struct ktr_info *info, const char *file, int line, __va_list va)
 447 {
 448         struct ktr_cpu_core *kcpu;
 449         struct ktr_entry *entry;
 450         int cpu;
 451
 452         cpu = mycpu->gd_cpuid;
 453         kcpu = &ktr_cpu[cpu].core;
 454         if (kcpu->ktr_buf == NULL)
 455                 return;
 456
 457         crit_enter();
 458         entry = kcpu->ktr_buf + (kcpu->ktr_idx & KTR_ENTRIES_MASK);
 459         ++kcpu->ktr_idx;
 460 #ifdef _RDTSC_SUPPORTED_
 461         if (cpu_feature & CPUID_TSC) {
 462 #ifdef SMP
 463                 entry->ktr_timestamp = rdtsc() - tsc_offsets[cpu];
 464 #else
 465                 entry->ktr_timestamp = rdtsc();
 466 #endif
 467         } else
 468 #endif
 469         {
 470                 entry->ktr_timestamp = get_approximate_time_t();
 471         }
 472         entry->ktr_info = info;
 473         entry->ktr_file = file;
 474         entry->ktr_line = line;
 475         crit_exit();
 476         if (info->kf_data_size > KTR_BUFSIZE)
 477                 bcopy(va, entry->ktr_data, KTR_BUFSIZE);
 478         else if (info->kf_data_size)
 479                 bcopy(va, entry->ktr_data, info->kf_data_size);
 480         if (ktr_stacktrace)
 481                 cpu_ktr_caller(entry);
 482 #ifdef KTR_VERBOSE
 483         if (ktr_verbose && info->kf_format) {
 484 #ifdef SMP
 485                 kprintf("cpu%d ", cpu);
 486 #endif
 487                 if (ktr_verbose > 1) {
 488                         kprintf("%s.%d\t", entry->ktr_file, entry->ktr_line);
 489                 }
 490                 kvprintf(info->kf_format, va);
 491                 kprintf("\n");
 492         }
 493 #endif
 494 }
 495
 496 void
 497 ktr_log(struct ktr_info *info, const char *file, int line, ...)
 498 {
 499         __va_list va;
 500
 501         if (panicstr == NULL) {
 502                 __va_start(va, line);
 503                 ktr_write_entry(info, file, line, va);
 504                 __va_end(va);
 505         }
 506 }
 507
 508 #ifdef DDB
 509
 510 #define NUM_LINES_PER_PAGE      19
 511
 512 struct tstate {
 513         int     cur;
 514         int     first;
 515 };
 516
 517 static  int db_ktr_verbose;
 518 static  int db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx);
 519
 520 DB_SHOW_COMMAND(ktr, db_ktr_all)
 521 {
 522         struct ktr_cpu_core *kcpu;
 523         int a_flag = 0;
 524         int c;
 525         int nl = 0;
 526         int i;
 527         struct tstate tstate[MAXCPU];
 528         int printcpu = -1;
 529
 530         for(i = 0; i < ncpus; i++) {
 531                 kcpu = &ktr_cpu[i].core;
 532                 tstate[i].first = -1;
 533                 tstate[i].cur = (kcpu->ktr_idx - 1) & KTR_ENTRIES_MASK;
 534         }
 535         db_ktr_verbose = 0;
 536         while ((c = *(modif++)) != '\0') {
 537                 if (c == 'v') {
 538                         db_ktr_verbose = 1;
 539                 }
 540                 else if (c == 'a') {
 541                         a_flag = 1;
 542                 }
 543                 else if (c == 'c') {
 544                         printcpu = 0;
 545                         while ((c = *(modif++)) != '\0') {
 546                                 if (isdigit(c)) {
 547                                         printcpu *= 10;
 548                                         printcpu += c - '0';
 549                                 }
 550                                 else {
 551                                         modif++;
 552                                         break;
 553                                 }
 554                         }
 555                         modif--;
 556                 }
 557         }
 558         if (printcpu > ncpus - 1) {
 559                 db_printf("Invalid cpu number\n");
 560                 return;
 561         }
 562         /*
 563          * Lopp throug all the buffers and print the content of them, sorted
 564          * by the timestamp.
 565          */
 566         while (1) {
 567                 int counter;
 568                 u_int64_t highest_ts;
 569                 int highest_cpu;
 570                 struct ktr_entry *kp;
 571
 572                 if (a_flag == 1 && cncheckc() != -1)
 573                         return;
 574                 highest_ts = 0;
 575                 highest_cpu = -1;
 576                 /*
 577                  * Find the lowest timestamp
 578                  */
 579                 for (i = 0, counter = 0; i < ncpus; i++) {
 580                         kcpu = &ktr_cpu[i].core;
 581                         if (kcpu->ktr_buf == NULL)
 582                                 continue;
 583                         if (printcpu != -1 && printcpu != i)
 584                                 continue;
 585                         if (tstate[i].cur == -1) {
 586                                 counter++;
 587                                 if (counter == ncpus) {
 588                                         db_printf("--- End of trace buffer ---\n");
 589                                         return;
 590                                 }
 591                                 continue;
 592                         }
 593                         if (kcpu->ktr_buf[tstate[i].cur].ktr_timestamp > highest_ts) {
 594                                 highest_ts = kcpu->ktr_buf[tstate[i].cur].ktr_timestamp;
 595                                 highest_cpu = i;
 596                         }
 597                 }
 598                 if (highest_cpu < 0) {
 599                         db_printf("no KTR data available\n");
 600                         break;
 601                 }
 602                 i = highest_cpu;
 603                 kcpu = &ktr_cpu[i].core;
 604                 kp = &kcpu->ktr_buf[tstate[i].cur];
 605                 if (tstate[i].first == -1)
 606                         tstate[i].first = tstate[i].cur;
 607                 if (--tstate[i].cur < 0)
 608                         tstate[i].cur = KTR_ENTRIES - 1;
 609                 if (tstate[i].first == tstate[i].cur) {
 610                         db_mach_vtrace(i, kp, tstate[i].cur + 1);
 611                         tstate[i].cur = -1;
 612                         continue;
 613                 }
 614                 if (kcpu->ktr_buf[tstate[i].cur].ktr_info == NULL)
 615                         tstate[i].cur = -1;
 616                 if (db_more(&nl) == -1)
 617                         break;
 618                 if (db_mach_vtrace(i, kp, tstate[i].cur + 1) == 0)
 619                         tstate[i].cur = -1;
 620         }
 621 }
 622
 623 static int
 624 db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx)
 625 {
 626         if (kp->ktr_info == NULL)
 627                 return(0);
 628 #ifdef SMP
 629         db_printf("cpu%d ", cpu);
 630 #endif
 631         db_printf("%d: ", idx);
 632         if (db_ktr_verbose) {
 633                 db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
 634                     kp->ktr_file, kp->ktr_line);
 635         }
 636         db_printf("%s\t", kp->ktr_info->kf_name);
 637         db_printf("from(%p,%p) ", kp->ktr_caller1, kp->ktr_caller2);
 638         if (kp->ktr_info->kf_format)
 639                 db_vprintf(kp->ktr_info->kf_format, (__va_list)kp->ktr_data);
 640         db_printf("\n");
 641
 642         return(1);
 643 }
 644
 645 #endif  /* DDB */