xref: /dragonfly/sys/kern/kern_ktr.c (revision 0085a56d)
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/kbio.h>
84 #include <sys/ctype.h>
85 #include <sys/limits.h>
86 
87 #include <sys/thread2.h>
88 #include <sys/spinlock2.h>
89 
90 #include <machine/cpu.h>
91 #include <machine/cpufunc.h>
92 #include <machine/specialreg.h>
93 #include <machine/md_var.h>
94 
95 #include <ddb/ddb.h>
96 
97 #ifndef KTR_ENTRIES
98 #define	KTR_ENTRIES		2048
99 #elif (KTR_ENTRIES & KTR_ENTRIES - 1)
100 #error KTR_ENTRIES must be a power of two
101 #endif
102 #define KTR_ENTRIES_MASK	(KTR_ENTRIES - 1)
103 
104 /*
105  * Used by earlier boot; default value consumes ~64K BSS.
106  *
107  * NOTE:
108  * We use a small value here; this prevents kernel or module loading
109  * failure due to excessive BSS usage if KTR_ENTRIES is large.
110  */
111 #if (KTR_ENTRIES < 256)
112 #define KTR_ENTRIES_BOOT0	KTR_ENTRIES
113 #else
114 #define KTR_ENTRIES_BOOT0	256
115 #endif
116 #define KTR_ENTRIES_BOOT0_MASK	(KTR_ENTRIES_BOOT0 - 1)
117 
118 /*
119  * test logging support.  When ktr_testlogcnt is non-zero each synchronization
120  * interrupt will issue six back-to-back ktr logging messages on cpu 0
121  * so the user can determine KTR logging overheads.
122  */
123 #if !defined(KTR_TESTLOG)
124 #define KTR_TESTLOG	KTR_ALL
125 #endif
126 KTR_INFO_MASTER(testlog);
127 #if KTR_TESTLOG
128 KTR_INFO(KTR_TESTLOG, testlog, charfmt, 0,
129     "charfmt %hhd %hhi %#hho %hhu %#hhx %#hhX\n",
130     signed char d1, signed char d2,
131     unsigned char d3, unsigned char d4,
132     unsigned char d5, unsigned char d6);
133 KTR_INFO(KTR_TESTLOG, testlog, shortfmt, 1,
134     "shortfmt %hd %hi %#ho %hu %#hx %#hX\n",
135     short d1, short d2,
136     unsigned short d3, unsigned short d4,
137     unsigned short d5, unsigned short d6);
138 KTR_INFO(KTR_TESTLOG, testlog, longfmt, 2,
139     "longfmt %ld %li %#lo %lu %#lx %#lX\n",
140     long d1, long d2,
141     unsigned long d3, unsigned long d4,
142     unsigned long d5, unsigned long d6);
143 KTR_INFO(KTR_TESTLOG, testlog, longlongfmt, 3,
144     "longlongfmt %lld %lli %#llo %llu %#llx %#llX\n",
145     long long d1, long long d2,
146     unsigned long long d3, unsigned long long d4,
147     unsigned long long d5, unsigned long long d6);
148 KTR_INFO(KTR_TESTLOG, testlog, intmaxfmt, 4,
149     "intmaxfmt %jd %ji %#jo %ju %#jx %#jX\n",
150     intmax_t d1, intmax_t d2,
151     uintmax_t d3, uintmax_t d4,
152     uintmax_t d5, uintmax_t d6);
153 KTR_INFO(KTR_TESTLOG, testlog, ptrdifffmt, 5,
154     "ptrdifffmt %td %ti\n",
155     ptrdiff_t d1, ptrdiff_t d2);
156 KTR_INFO(KTR_TESTLOG, testlog, sizefmt, 6,
157     "sizefmt %zd %zi %#zo %zu %#zx %#zX\n",
158     ssize_t d1, ssize_t d2,
159     size_t d3, size_t d4,
160     size_t d5, size_t d6);
161 KTR_INFO(KTR_TESTLOG, testlog, pingpong, 17, "pingpong");
162 KTR_INFO(KTR_TESTLOG, testlog, pipeline, 18, "pipeline");
163 KTR_INFO(KTR_TESTLOG, testlog, crit_beg, 19, "crit_beg");
164 KTR_INFO(KTR_TESTLOG, testlog, crit_end, 20, "crit_end");
165 KTR_INFO(KTR_TESTLOG, testlog, spin_beg, 21, "spin_beg");
166 KTR_INFO(KTR_TESTLOG, testlog, spin_end, 22, "spin_end");
167 #define logtest_noargs(name)	KTR_LOG(testlog_ ## name)
168 #endif
169 
170 MALLOC_DEFINE(M_KTR, "ktr", "ktr buffers");
171 
172 SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RW, 0, "ktr");
173 
174 static int	ktr_entries = KTR_ENTRIES_BOOT0;
175 SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0,
176     "Size of the event buffer");
177 static int	ktr_entries_mask = KTR_ENTRIES_BOOT0_MASK;
178 
179 static int	ktr_version = KTR_VERSION;
180 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, &ktr_version, 0, "");
181 
182 static int	ktr_stacktrace = 1;
183 SYSCTL_INT(_debug_ktr, OID_AUTO, stacktrace, CTLFLAG_RD, &ktr_stacktrace, 0, "");
184 
185 static int	ktr_resynchronize = 0;
186 SYSCTL_INT(_debug_ktr, OID_AUTO, resynchronize, CTLFLAG_RW,
187     &ktr_resynchronize, 0, "Resynchronize TSC 10 times a second");
188 
189 #if KTR_TESTLOG
190 static int	ktr_testlogcnt = 0;
191 SYSCTL_INT(_debug_ktr, OID_AUTO, testlogcnt, CTLFLAG_RW, &ktr_testlogcnt, 0, "");
192 static int	ktr_testipicnt = 0;
193 static int	ktr_testipicnt_remainder;
194 SYSCTL_INT(_debug_ktr, OID_AUTO, testipicnt, CTLFLAG_RW, &ktr_testipicnt, 0, "");
195 static int	ktr_testcritcnt = 0;
196 SYSCTL_INT(_debug_ktr, OID_AUTO, testcritcnt, CTLFLAG_RW, &ktr_testcritcnt, 0, "");
197 static int	ktr_testspincnt = 0;
198 SYSCTL_INT(_debug_ktr, OID_AUTO, testspincnt, CTLFLAG_RW, &ktr_testspincnt, 0, "");
199 #endif
200 
201 /*
202  * Give cpu0 a static buffer so the tracepoint facility can be used during
203  * early boot (note however that we still use a critical section, XXX).
204  */
205 static struct	ktr_entry ktr_buf0[KTR_ENTRIES_BOOT0];
206 
207 struct ktr_cpu ktr_cpu[MAXCPU] = {
208 	{ .core.ktr_buf = &ktr_buf0[0] }
209 };
210 
211 static int64_t	ktr_sync_tsc;
212 struct callout	ktr_resync_callout;
213 
214 #ifdef KTR_VERBOSE
215 int	ktr_verbose = KTR_VERBOSE;
216 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
217 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0,
218     "Log events to the console as well");
219 #endif
220 
221 static void ktr_resync_callback(void *dummy __unused);
222 
223 extern int64_t tsc_offsets[];
224 
225 static void
226 ktr_sysinit(void *dummy)
227 {
228 	struct ktr_cpu_core *kcpu;
229 	int i;
230 
231 	for (i = 0; i < ncpus; ++i) {
232 		kcpu = &ktr_cpu[i].core;
233 		kcpu->ktr_buf = kmalloc(KTR_ENTRIES * sizeof(struct ktr_entry),
234 					M_KTR, M_WAITOK | M_ZERO);
235 		if (i == 0) {
236 			/* Migrate ktrs on CPU0 to the new location */
237 			memcpy(kcpu->ktr_buf, ktr_buf0, sizeof(ktr_buf0));
238 		}
239 	}
240 	cpu_sfence();
241 	ktr_entries = KTR_ENTRIES;
242 	ktr_entries_mask = KTR_ENTRIES_MASK;
243 
244 	callout_init_mp(&ktr_resync_callout);
245 	callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
246 }
247 SYSINIT(ktr_sysinit, SI_BOOT2_KLD, SI_ORDER_ANY, ktr_sysinit, NULL);
248 
249 /*
250  * Try to resynchronize the TSC's for all cpus.  This is really, really nasty.
251  * We have to send an IPIQ message to all remote cpus, wait until they
252  * get into their IPIQ processing code loop, then do an even stricter hard
253  * loop to get the cpus as close to synchronized as we can to get the most
254  * accurate reading.
255  *
256  * This callback occurs on cpu0.
257  */
258 #if KTR_TESTLOG
259 static void ktr_pingpong_remote(void *dummy);
260 static void ktr_pipeline_remote(void *dummy);
261 #endif
262 
263 #ifdef _RDTSC_SUPPORTED_
264 
265 static void ktr_resync_remote(void *dummy);
266 
267 /*
268  * We use a callout callback instead of a systimer because we cannot afford
269  * to preempt anyone to do this, or we might deadlock a spin-lock or
270  * serializer between two cpus.
271  */
272 static
273 void
274 ktr_resync_callback(void *dummy __unused)
275 {
276 	struct lwkt_cpusync cs;
277 #if KTR_TESTLOG
278 	int count;
279 #endif
280 
281 	KKASSERT(mycpu->gd_cpuid == 0);
282 
283 #if KTR_TESTLOG
284 	/*
285 	 * Test logging
286 	 */
287 	if (ktr_testlogcnt) {
288 		--ktr_testlogcnt;
289 		cpu_disable_intr();
290 		KTR_LOG(testlog_charfmt,
291 		    (signed char)UCHAR_MAX, (signed char)UCHAR_MAX,
292 		    (unsigned char)-1, (unsigned char)-1,
293 		    (unsigned char)-1, (unsigned char)-1);
294 		KTR_LOG(testlog_shortfmt,
295 		    (short)USHRT_MAX, (short)USHRT_MAX,
296 		    (unsigned short)-1, (unsigned short)-1,
297 		    (unsigned short)-1, (unsigned short)-1);
298 		KTR_LOG(testlog_longfmt,
299 		    (long)ULONG_MAX, (long)ULONG_MAX,
300 		    (unsigned long)-1, (unsigned long)-1,
301 		    (unsigned long)-1, (unsigned long)-1);
302 		KTR_LOG(testlog_longlongfmt,
303 		    (long long)ULLONG_MAX, (long long)ULLONG_MAX,
304 		    (unsigned long long)-1, (unsigned long long)-1,
305 		    (unsigned long long)-1, (unsigned long long)-1);
306 		KTR_LOG(testlog_intmaxfmt,
307 		    (intmax_t)UINTMAX_MAX, (intmax_t)UINTMAX_MAX,
308 		    (uintmax_t)-1, (uintmax_t)-1,
309 		    (uintmax_t)-1, (uintmax_t)-1);
310 		KTR_LOG(testlog_ptrdifffmt,
311 		    (ptrdiff_t)PTRDIFF_MAX, (ptrdiff_t)PTRDIFF_MAX);
312 		KTR_LOG(testlog_sizefmt,
313 		    (ssize_t)SIZE_T_MAX, (ssize_t)SIZE_T_MAX,
314 		    (size_t)-1, (size_t)-1,
315 		    (size_t)-1, (size_t)-1);
316 		cpu_enable_intr();
317 	}
318 
319 	/*
320 	 * Test IPI messaging
321 	 */
322 	if (ktr_testipicnt && ktr_testipicnt_remainder == 0 && ncpus > 1) {
323 		ktr_testipicnt_remainder = ktr_testipicnt;
324 		ktr_testipicnt = 0;
325 		lwkt_send_ipiq_bycpu(1, ktr_pingpong_remote, NULL);
326 	}
327 
328 	/*
329 	 * Test critical sections
330 	 */
331 	if (ktr_testcritcnt) {
332 		crit_enter();
333 		crit_exit();
334 		logtest_noargs(crit_beg);
335 		for (count = ktr_testcritcnt; count; --count) {
336 			crit_enter();
337 			crit_exit();
338 		}
339 		logtest_noargs(crit_end);
340 		ktr_testcritcnt = 0;
341 	}
342 
343 	/*
344 	 * Test spinlock sections
345 	 */
346 	if (ktr_testspincnt) {
347 		struct spinlock spin;
348 
349 		spin_init(&spin, "ktrresync");
350 		spin_lock(&spin);
351 		spin_unlock(&spin);
352 		logtest_noargs(spin_beg);
353 		for (count = ktr_testspincnt; count; --count) {
354 			spin_lock(&spin);
355 			spin_unlock(&spin);
356 		}
357 		logtest_noargs(spin_end);
358 		ktr_testspincnt = 0;
359 	}
360 #endif
361 
362 	/*
363 	 * Resynchronize the TSC
364 	 */
365 	if (ktr_resynchronize == 0)
366 		goto done;
367 	if ((cpu_feature & CPUID_TSC) == 0)
368 		return;
369 
370 	crit_enter();
371 	lwkt_cpusync_init(&cs, smp_active_mask, ktr_resync_remote,
372 			  (void *)(intptr_t)mycpu->gd_cpuid);
373 	lwkt_cpusync_interlock(&cs);
374 	ktr_sync_tsc = rdtsc();
375 	lwkt_cpusync_deinterlock(&cs);
376 	crit_exit();
377 done:
378 	callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
379 }
380 
381 /*
382  * The remote-end of the KTR synchronization protocol runs on all cpus.
383  * The one we run on the controlling cpu updates its tsc continuously
384  * until the others have finished syncing (theoretically), but we don't
385  * loop forever.
386  *
387  * This is a bit ad-hoc but we need to avoid livelocking inside an IPI
388  * callback.  rdtsc() is a synchronizing instruction (I think).
389  */
390 static void
391 ktr_resync_remote(void *arg)
392 {
393 	globaldata_t gd = mycpu;
394 	int64_t delta;
395 	int i;
396 
397 	if (gd->gd_cpuid == (int)(intptr_t)arg) {
398 		for (i = 0; i < 2000; ++i)
399 			ktr_sync_tsc = rdtsc();
400 	} else {
401 		delta = rdtsc() - ktr_sync_tsc;
402 		if (tsc_offsets[gd->gd_cpuid] == 0)
403 			tsc_offsets[gd->gd_cpuid] = delta;
404 		tsc_offsets[gd->gd_cpuid] =
405 			(tsc_offsets[gd->gd_cpuid] * 7 + delta) / 8;
406 	}
407 }
408 
409 #if KTR_TESTLOG
410 
411 static
412 void
413 ktr_pingpong_remote(void *dummy __unused)
414 {
415 	int other_cpu;
416 
417 	logtest_noargs(pingpong);
418 	other_cpu = 1 - mycpu->gd_cpuid;
419 	if (ktr_testipicnt_remainder) {
420 		--ktr_testipicnt_remainder;
421 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pingpong_remote, NULL);
422 	} else {
423 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
424 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
425 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
426 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
427 		lwkt_send_ipiq_bycpu(other_cpu, ktr_pipeline_remote, NULL);
428 	}
429 }
430 
431 static
432 void
433 ktr_pipeline_remote(void *dummy __unused)
434 {
435 	logtest_noargs(pipeline);
436 }
437 
438 #endif
439 
440 #else	/* !_RDTSC_SUPPORTED_ */
441 
442 /*
443  * The resync callback for UP doesn't do anything other then run the test
444  * log messages.  If test logging is not enabled, don't bother resetting
445  * the callout.
446  */
447 static
448 void
449 ktr_resync_callback(void *dummy __unused)
450 {
451 #if KTR_TESTLOG
452 	/*
453 	 * Test logging
454 	 */
455 	if (ktr_testlogcnt) {
456 		--ktr_testlogcnt;
457 		cpu_disable_intr();
458 		KTR_LOG(testlog_charfmt,
459 		    (signed char)UCHAR_MAX, (signed char)UCHAR_MAX,
460 		    (unsigned char)-1, (unsigned char)-1,
461 		    (unsigned char)-1, (unsigned char)-1);
462 		KTR_LOG(testlog_shortfmt,
463 		    (short)USHRT_MAX, (short)USHRT_MAX,
464 		    (unsigned short)-1, (unsigned short)-1,
465 		    (unsigned short)-1, (unsigned short)-1);
466 		KTR_LOG(testlog_longfmt,
467 		    (long)ULONG_MAX, (long)ULONG_MAX,
468 		    (unsigned long)-1, (unsigned long)-1,
469 		    (unsigned long)-1, (unsigned long)-1);
470 		KTR_LOG(testlog_longlongfmt,
471 		    (long long)ULLONG_MAX, (long long)ULLONG_MAX,
472 		    (unsigned long long)-1, (unsigned long long)-1,
473 		    (unsigned long long)-1, (unsigned long long)-1);
474 		KTR_LOG(testlog_intmaxfmt,
475 		    (intmax_t)UINTMAX_MAX, (intmax_t)UINTMAX_MAX,
476 		    (uintmax_t)-1, (uintmax_t)-1,
477 		    (uintmax_t)-1, (uintmax_t)-1);
478 		KTR_LOG(testlog_ptrdifffmt,
479 		    (ptrdiff_t)PTRDIFF_MAX, (ptrdiff_t)PTRDIFF_MAX);
480 		KTR_LOG(testlog_sizefmt,
481 		    (ssize_t)SIZE_T_MAX, (ssize_t)SIZE_T_MAX,
482 		    (size_t)-1, (size_t)-1,
483 		    (size_t)-1, (size_t)-1);
484 		cpu_enable_intr();
485 	}
486 	callout_reset(&ktr_resync_callout, hz / 10, ktr_resync_callback, NULL);
487 #endif
488 }
489 
490 #endif
491 
492 /*
493  * Setup the next empty slot and return it to the caller to store the data
494  * directly.
495  */
496 struct ktr_entry *
497 ktr_begin_write_entry(struct ktr_info *info, const char *file, int line)
498 {
499 	struct ktr_cpu_core *kcpu;
500 	struct ktr_entry *entry;
501 	int cpu;
502 
503 	cpu = mycpu->gd_cpuid;
504 	kcpu = &ktr_cpu[cpu].core;
505 	if (panicstr)			/* stop logging during panic */
506 		return NULL;
507 	if (kcpu->ktr_buf == NULL)	/* too early in boot */
508 		return NULL;
509 
510 	crit_enter();
511 	entry = kcpu->ktr_buf + (kcpu->ktr_idx & ktr_entries_mask);
512 	++kcpu->ktr_idx;
513 #ifdef _RDTSC_SUPPORTED_
514 	if (cpu_feature & CPUID_TSC) {
515 		entry->ktr_timestamp = rdtsc() - tsc_offsets[cpu];
516 	} else
517 #endif
518 	{
519 		entry->ktr_timestamp = get_approximate_time_t();
520 	}
521 	entry->ktr_info = info;
522 	entry->ktr_file = file;
523 	entry->ktr_line = line;
524 	crit_exit();
525 	return entry;
526 }
527 
528 int
529 ktr_finish_write_entry(struct ktr_info *info, struct ktr_entry *entry)
530 {
531 	if (ktr_stacktrace)
532 		cpu_ktr_caller(entry);
533 #ifdef KTR_VERBOSE
534 	if (ktr_verbose && info->kf_format) {
535 		kprintf("cpu%d ", mycpu->gd_cpuid);
536 		if (ktr_verbose > 1) {
537 			kprintf("%s.%d\t", entry->ktr_file, entry->ktr_line);
538 		}
539 		return !0;
540 	}
541 #endif
542 	return 0;
543 }
544 
545 #ifdef DDB
546 
547 #define	NUM_LINES_PER_PAGE	19
548 
549 struct tstate {
550 	int	cur;
551 	int	first;
552 };
553 
554 static	int db_ktr_verbose;
555 static	int db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx);
556 
557 DB_SHOW_COMMAND(ktr, db_ktr_all)
558 {
559 	struct ktr_cpu_core *kcpu;
560 	int a_flag = 0;
561 	int c;
562 	int nl = 0;
563 	int i;
564 	struct tstate tstate[MAXCPU];
565 	int printcpu = -1;
566 
567 	for(i = 0; i < ncpus; i++) {
568 		kcpu = &ktr_cpu[i].core;
569 		tstate[i].first = -1;
570 		tstate[i].cur = (kcpu->ktr_idx - 1) & ktr_entries_mask;
571 	}
572 	db_ktr_verbose = 0;
573 	while ((c = *(modif++)) != '\0') {
574 		if (c == 'v') {
575 			db_ktr_verbose = 1;
576 		}
577 		else if (c == 'a') {
578 			a_flag = 1;
579 		}
580 		else if (c == 'c') {
581 			printcpu = 0;
582 			while ((c = *(modif++)) != '\0') {
583 				if (isdigit(c)) {
584 					printcpu *= 10;
585 					printcpu += c - '0';
586 				}
587 				else {
588 					modif++;
589 					break;
590 				}
591 			}
592 			modif--;
593 		}
594 	}
595 	if (printcpu > ncpus - 1) {
596 		db_printf("Invalid cpu number\n");
597 		return;
598 	}
599 	/*
600 	 * Loop throug all the buffers and print the content of them, sorted
601 	 * by the timestamp.
602 	 */
603 	while (1) {
604 		int counter;
605 		u_int64_t highest_ts;
606 		struct ktr_entry *kp;
607 		int highest_cpu;
608 		int c;
609 
610 		if (a_flag == 1) {
611 			c = cncheckc();
612 			if (c != -1 && c != NOKEY)
613 				return;
614 		}
615 		highest_ts = 0;
616 		highest_cpu = -1;
617 		/*
618 		 * Find the lowest timestamp
619 		 */
620 		for (i = 0, counter = 0; i < ncpus; i++) {
621 			kcpu = &ktr_cpu[i].core;
622 			if (kcpu->ktr_buf == NULL)
623 				continue;
624 			if (printcpu != -1 && printcpu != i)
625 				continue;
626 			if (tstate[i].cur == -1) {
627 				counter++;
628 				if (counter == ncpus) {
629 					db_printf("--- End of trace buffer ---\n");
630 					return;
631 				}
632 				continue;
633 			}
634 			if (kcpu->ktr_buf[tstate[i].cur].ktr_timestamp > highest_ts) {
635 				highest_ts = kcpu->ktr_buf[tstate[i].cur].ktr_timestamp;
636 				highest_cpu = i;
637 			}
638 		}
639 		if (highest_cpu < 0) {
640 			db_printf("no KTR data available\n");
641 			break;
642 		}
643 		i = highest_cpu;
644 		kcpu = &ktr_cpu[i].core;
645 		kp = &kcpu->ktr_buf[tstate[i].cur];
646 		if (tstate[i].first == -1)
647 			tstate[i].first = tstate[i].cur;
648 		if (--tstate[i].cur < 0)
649 			tstate[i].cur = ktr_entries - 1;
650 		if (tstate[i].first == tstate[i].cur) {
651 			db_mach_vtrace(i, kp, tstate[i].cur + 1);
652 			tstate[i].cur = -1;
653 			continue;
654 		}
655 		if (kcpu->ktr_buf[tstate[i].cur].ktr_info == NULL)
656 			tstate[i].cur = -1;
657 		if (db_more(&nl) == -1)
658 			break;
659 		if (db_mach_vtrace(i, kp, tstate[i].cur + 1) == 0)
660 			tstate[i].cur = -1;
661 	}
662 }
663 
664 static int
665 db_mach_vtrace(int cpu, struct ktr_entry *kp, int idx)
666 {
667 	if (kp->ktr_info == NULL)
668 		return(0);
669 	db_printf("cpu%d ", cpu);
670 	db_printf("%d: ", idx);
671 	if (db_ktr_verbose) {
672 		db_printf("%10.10lld %s.%d\t", (long long)kp->ktr_timestamp,
673 		    kp->ktr_file, kp->ktr_line);
674 	}
675 	db_printf("%s\t", kp->ktr_info->kf_name);
676 	db_printf("from(%p,%p) ", kp->ktr_caller1, kp->ktr_caller2);
677 	db_printf("\n");
678 
679 	return(1);
680 }
681 
682 #endif	/* DDB */
683