xref: /freebsd/usr.sbin/pmcstat/pmcpl_callgraph.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2007, Joseph Koshy
5  * Copyright (c) 2007 The FreeBSD Foundation
6  * All rights reserved.
7  *
8  * Portions of this software were developed by A. Joseph Koshy under
9  * sponsorship from the FreeBSD Foundation and Google, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Transform a hwpmc(4) log into human readable form, and into
35  * gprof(1) compatible profiles.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/endian.h>
43 #include <sys/gmon.h>
44 #include <sys/imgact_aout.h>
45 #include <sys/imgact_elf.h>
46 #include <sys/mman.h>
47 #include <sys/pmc.h>
48 #include <sys/queue.h>
49 #include <sys/socket.h>
50 #include <sys/stat.h>
51 #include <sys/wait.h>
52 
53 #include <netinet/in.h>
54 
55 #include <assert.h>
56 #include <curses.h>
57 #include <err.h>
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <gelf.h>
61 #include <inttypes.h>
62 #include <libgen.h>
63 #include <limits.h>
64 #include <netdb.h>
65 #include <pmc.h>
66 #include <pmclog.h>
67 #include <sysexits.h>
68 #include <stdint.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <unistd.h>
73 
74 #include "pmcstat.h"
75 #include "pmcstat_log.h"
76 #include "pmcstat_top.h"
77 #include "pmcpl_callgraph.h"
78 
79 #define	min(A,B)		((A) < (B) ? (A) : (B))
80 #define	max(A,B)		((A) > (B) ? (A) : (B))
81 
82 /* Get the sample value in percent related to nsamples. */
83 #define PMCPL_CG_COUNTP(a) \
84 	((a)->pcg_count * 100.0 / nsamples)
85 
86 /*
87  * The toplevel CG nodes (i.e., with rank == 0) are placed in a hash table.
88  */
89 
90 struct pmcstat_cgnode_hash_list pmcstat_cgnode_hash[PMCSTAT_NHASH];
91 int pmcstat_cgnode_hash_count;
92 
93 static pmcstat_interned_string pmcstat_previous_filename_printed;
94 
95 static struct pmcstat_cgnode *
96 pmcstat_cgnode_allocate(struct pmcstat_image *image, uintfptr_t pc)
97 {
98 	struct pmcstat_cgnode *cg;
99 
100 	if ((cg = malloc(sizeof(*cg))) == NULL)
101 		err(EX_OSERR, "ERROR: Cannot allocate callgraph node");
102 
103 	cg->pcg_image = image;
104 	cg->pcg_func = pc;
105 
106 	cg->pcg_count = 0;
107 	cg->pcg_nchildren = 0;
108 	LIST_INIT(&cg->pcg_children);
109 
110 	return (cg);
111 }
112 
113 /*
114  * Free a node and its children.
115  */
116 static void
117 pmcstat_cgnode_free(struct pmcstat_cgnode *cg)
118 {
119 	struct pmcstat_cgnode *cgc, *cgtmp;
120 
121 	LIST_FOREACH_SAFE(cgc, &cg->pcg_children, pcg_sibling, cgtmp)
122 		pmcstat_cgnode_free(cgc);
123 	free(cg);
124 }
125 
126 /*
127  * Look for a callgraph node associated with pmc `pmcid' in the global
128  * hash table that corresponds to the given `pc' value in the process
129  * `pp'.
130  */
131 static struct pmcstat_cgnode *
132 pmcstat_cgnode_hash_lookup_pc(struct pmcstat_process *pp, pmc_id_t pmcid,
133     uintfptr_t pc, int usermode)
134 {
135 	struct pmcstat_pcmap *ppm;
136 	struct pmcstat_symbol *sym;
137 	struct pmcstat_image *image;
138 	struct pmcstat_cgnode *cg;
139 	struct pmcstat_cgnode_hash *h;
140 	uintfptr_t loadaddress;
141 	unsigned int i, hash;
142 
143 	ppm = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, pc);
144 	if (ppm == NULL)
145 		return (NULL);
146 
147 	image = ppm->ppm_image;
148 
149 	loadaddress = ppm->ppm_lowpc + image->pi_vaddr - image->pi_start;
150 	pc -= loadaddress;	/* Convert to an offset in the image. */
151 
152 	/*
153 	 * Try determine the function at this offset.  If we can't
154 	 * find a function round leave the `pc' value alone.
155 	 */
156 	if (!(args.pa_flags & (FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET))) {
157 		if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
158 			pc = sym->ps_start;
159 		else
160 			pmcstat_stats.ps_samples_unknown_function++;
161 	}
162 
163 	for (hash = i = 0; i < sizeof(uintfptr_t); i++)
164 		hash += (pc >> i) & 0xFF;
165 
166 	hash &= PMCSTAT_HASH_MASK;
167 
168 	cg = NULL;
169 	LIST_FOREACH(h, &pmcstat_cgnode_hash[hash], pch_next)
170 	{
171 		if (h->pch_pmcid != pmcid)
172 			continue;
173 
174 		cg = h->pch_cgnode;
175 
176 		assert(cg != NULL);
177 
178 		if (cg->pcg_image == image && cg->pcg_func == pc)
179 			return (cg);
180 	}
181 
182 	/*
183 	 * We haven't seen this (pmcid, pc) tuple yet, so allocate a
184 	 * new callgraph node and a new hash table entry for it.
185 	 */
186 	cg = pmcstat_cgnode_allocate(image, pc);
187 	if ((h = malloc(sizeof(*h))) == NULL)
188 		err(EX_OSERR, "ERROR: Could not allocate callgraph node");
189 
190 	h->pch_pmcid = pmcid;
191 	h->pch_cgnode = cg;
192 	LIST_INSERT_HEAD(&pmcstat_cgnode_hash[hash], h, pch_next);
193 
194 	pmcstat_cgnode_hash_count++;
195 
196 	return (cg);
197 }
198 
199 /*
200  * Compare two callgraph nodes for sorting.
201  */
202 static int
203 pmcstat_cgnode_compare(const void *a, const void *b)
204 {
205 	const struct pmcstat_cgnode *const *pcg1, *const *pcg2, *cg1, *cg2;
206 
207 	pcg1 = (const struct pmcstat_cgnode *const *) a;
208 	cg1 = *pcg1;
209 	pcg2 = (const struct pmcstat_cgnode *const *) b;
210 	cg2 = *pcg2;
211 
212 	/* Sort in reverse order */
213 	if (cg1->pcg_count < cg2->pcg_count)
214 		return (1);
215 	if (cg1->pcg_count > cg2->pcg_count)
216 		return (-1);
217 	return (0);
218 }
219 
220 /*
221  * Find (allocating if a needed) a callgraph node in the given
222  * parent with the same (image, pcoffset) pair.
223  */
224 
225 static struct pmcstat_cgnode *
226 pmcstat_cgnode_find(struct pmcstat_cgnode *parent, struct pmcstat_image *image,
227     uintfptr_t pcoffset)
228 {
229 	struct pmcstat_cgnode *child;
230 
231 	LIST_FOREACH(child, &parent->pcg_children, pcg_sibling) {
232 		if (child->pcg_image == image &&
233 		    child->pcg_func == pcoffset)
234 			return (child);
235 	}
236 
237 	/*
238 	 * Allocate a new structure.
239 	 */
240 
241 	child = pmcstat_cgnode_allocate(image, pcoffset);
242 
243 	/*
244 	 * Link it into the parent.
245 	 */
246 	LIST_INSERT_HEAD(&parent->pcg_children, child, pcg_sibling);
247 	parent->pcg_nchildren++;
248 
249 	return (child);
250 }
251 
252 /*
253  * Print one callgraph node.  The output format is:
254  *
255  * indentation %(parent's samples) #nsamples function@object
256  */
257 static void
258 pmcstat_cgnode_print(struct pmcstat_cgnode *cg, int depth, uint32_t total)
259 {
260 	uint32_t n;
261 	const char *space;
262 	struct pmcstat_symbol *sym;
263 	struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;
264 
265 	space = " ";
266 
267 	if (depth > 0)
268 		(void) fprintf(args.pa_graphfile, "%*s", depth, space);
269 
270 	if (cg->pcg_count == total)
271 		(void) fprintf(args.pa_graphfile, "100.0%% ");
272 	else
273 		(void) fprintf(args.pa_graphfile, "%05.2f%% ",
274 		    100.0 * cg->pcg_count / total);
275 
276 	n = fprintf(args.pa_graphfile, " [%u] ", cg->pcg_count);
277 
278 	/* #samples is a 12 character wide field. */
279 	if (n < 12)
280 		(void) fprintf(args.pa_graphfile, "%*s", 12 - n, space);
281 
282 	if (depth > 0)
283 		(void) fprintf(args.pa_graphfile, "%*s", depth, space);
284 
285 	sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
286 	if (sym)
287 		(void) fprintf(args.pa_graphfile, "%s",
288 		    pmcstat_string_unintern(sym->ps_name));
289 	else
290 		(void) fprintf(args.pa_graphfile, "%p",
291 		    (void *) (cg->pcg_image->pi_vaddr + cg->pcg_func));
292 
293 	if (pmcstat_previous_filename_printed !=
294 	    cg->pcg_image->pi_fullpath) {
295 		pmcstat_previous_filename_printed = cg->pcg_image->pi_fullpath;
296 		(void) fprintf(args.pa_graphfile, " @ %s\n",
297 		    pmcstat_string_unintern(
298 		    pmcstat_previous_filename_printed));
299 	} else
300 		(void) fprintf(args.pa_graphfile, "\n");
301 
302 	if (cg->pcg_nchildren == 0)
303 		return;
304 
305 	if ((sortbuffer = (struct pmcstat_cgnode **)
306 		malloc(sizeof(struct pmcstat_cgnode *) *
307 		    cg->pcg_nchildren)) == NULL)
308 		err(EX_OSERR, "ERROR: Cannot print callgraph");
309 	cgn = sortbuffer;
310 
311 	LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
312 	    *cgn++ = pcg;
313 
314 	assert(cgn - sortbuffer == (int) cg->pcg_nchildren);
315 
316 	qsort(sortbuffer, cg->pcg_nchildren, sizeof(struct pmcstat_cgnode *),
317 	    pmcstat_cgnode_compare);
318 
319 	for (cgn = sortbuffer, n = 0; n < cg->pcg_nchildren; n++, cgn++)
320 		pmcstat_cgnode_print(*cgn, depth+1, cg->pcg_count);
321 
322 	free(sortbuffer);
323 }
324 
325 /*
326  * Record a callchain.
327  */
328 
329 void
330 pmcpl_cg_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
331     uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
332 {
333 	uintfptr_t pc, loadaddress;
334 	uint32_t n;
335 	struct pmcstat_image *image;
336 	struct pmcstat_pcmap *ppm;
337 	struct pmcstat_symbol *sym;
338 	struct pmcstat_cgnode *parent, *child;
339 	struct pmcstat_process *km;
340 	pmc_id_t pmcid;
341 
342 	(void) cpu;
343 
344 	/*
345 	 * Find the callgraph node recorded in the global hash table
346 	 * for this (pmcid, pc).
347 	 */
348 
349 	pc = cc[0];
350 	pmcid = pmcr->pr_pmcid;
351 	child = parent = pmcstat_cgnode_hash_lookup_pc(pp, pmcid, pc, usermode);
352 	if (parent == NULL) {
353 		pmcstat_stats.ps_callchain_dubious_frames++;
354 		pmcr->pr_dubious_frames++;
355 		return;
356 	}
357 
358 	parent->pcg_count++;
359 
360 	/*
361 	 * For each return address in the call chain record, subject
362 	 * to the maximum depth desired.
363 	 * - Find the image associated with the sample.  Stop if there
364 	 *   there is no valid image at that address.
365 	 * - Find the function that overlaps the return address.
366 	 * - If found: use the start address of the function.
367 	 *   If not found (say an object's symbol table is not present or
368 	 *   is incomplete), round down to th gprof bucket granularity.
369 	 * - Convert return virtual address to an offset in the image.
370 	 * - Look for a child with the same {offset,image} tuple,
371 	 *   inserting one if needed.
372 	 * - Increment the count of occurrences of the child.
373 	 */
374 	km = pmcstat_kernproc;
375 
376 	for (n = 1; n < (uint32_t) args.pa_graphdepth && n < nsamples; n++,
377 	    parent = child) {
378 		pc = cc[n];
379 
380 		ppm = pmcstat_process_find_map(usermode ? pp : km, pc);
381 		if (ppm == NULL) {
382 			/* Detect full frame capture (kernel + user). */
383 			if (!usermode) {
384 				ppm = pmcstat_process_find_map(pp, pc);
385 				if (ppm != NULL)
386 					km = pp;
387 			}
388 		}
389 		if (ppm == NULL)
390 			continue;
391 
392 		image = ppm->ppm_image;
393 		loadaddress = ppm->ppm_lowpc + image->pi_vaddr -
394 		    image->pi_start;
395 		pc -= loadaddress;
396 
397 		if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
398 			pc = sym->ps_start;
399 
400 		child = pmcstat_cgnode_find(parent, image, pc);
401 		child->pcg_count++;
402 	}
403 }
404 
405 /*
406  * Printing a callgraph for a PMC.
407  */
408 static void
409 pmcstat_callgraph_print_for_pmcid(struct pmcstat_pmcrecord *pmcr)
410 {
411 	int n, nentries;
412 	uint32_t nsamples;
413 	pmc_id_t pmcid;
414 	struct pmcstat_cgnode **sortbuffer, **cgn;
415 	struct pmcstat_cgnode_hash *pch;
416 
417 	/*
418 	 * We pull out all callgraph nodes in the top-level hash table
419 	 * with a matching PMC id.  We then sort these based on the
420 	 * frequency of occurrence.  Each callgraph node is then
421 	 * printed.
422 	 */
423 
424 	nsamples = 0;
425 	pmcid = pmcr->pr_pmcid;
426 	if ((sortbuffer = (struct pmcstat_cgnode **)
427 	    malloc(sizeof(struct pmcstat_cgnode *) *
428 	    pmcstat_cgnode_hash_count)) == NULL)
429 		err(EX_OSERR, "ERROR: Cannot sort callgraph");
430 	cgn = sortbuffer;
431 
432 	for (n = 0; n < PMCSTAT_NHASH; n++)
433 		LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
434 		    if (pch->pch_pmcid == pmcid) {
435 			    nsamples += pch->pch_cgnode->pcg_count;
436 			    *cgn++ = pch->pch_cgnode;
437 		    }
438 
439 	nentries = cgn - sortbuffer;
440 	assert(nentries <= pmcstat_cgnode_hash_count);
441 
442 	if (nentries == 0) {
443 		free(sortbuffer);
444 		return;
445 	}
446 
447 	qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
448 	    pmcstat_cgnode_compare);
449 
450 	(void) fprintf(args.pa_graphfile,
451 	    "@ %s [%u samples]\n\n",
452 	    pmcstat_string_unintern(pmcr->pr_pmcname),
453 	    nsamples);
454 
455 	for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
456 		pmcstat_previous_filename_printed = NULL;
457 		pmcstat_cgnode_print(*cgn, 0, nsamples);
458 		(void) fprintf(args.pa_graphfile, "\n");
459 	}
460 
461 	free(sortbuffer);
462 }
463 
464 /*
465  * Print out callgraphs.
466  */
467 
468 static void
469 pmcstat_callgraph_print(void)
470 {
471 	struct pmcstat_pmcrecord *pmcr;
472 
473 	LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
474 	    pmcstat_callgraph_print_for_pmcid(pmcr);
475 }
476 
477 static void
478 pmcstat_cgnode_topprint(struct pmcstat_cgnode *cg,
479     int depth __unused, uint32_t nsamples)
480 {
481 	int v_attrs, vs_len, ns_len, width, len, n, nchildren;
482 	float v;
483 	char ns[30], vs[10];
484 	struct pmcstat_symbol *sym;
485 	struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;
486 
487 	/* Format value. */
488 	v = PMCPL_CG_COUNTP(cg);
489 	snprintf(vs, sizeof(vs), "%.1f", v);
490 	v_attrs = PMCSTAT_ATTRPERCENT(v);
491 
492 	/* Format name. */
493 	sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
494 	if (sym == NULL) {
495 		snprintf(ns, sizeof(ns), "%p",
496 		    (void *)(cg->pcg_image->pi_vaddr + cg->pcg_func));
497 	} else {
498 		switch (args.pa_flags & (FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET)) {
499 		case FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET:
500 		case FLAG_SKIP_TOP_FN_RES:
501 			snprintf(ns, sizeof(ns), "%p",
502 			    (void *)(cg->pcg_image->pi_vaddr + cg->pcg_func));
503 			break;
504 		case FLAG_SHOW_OFFSET:
505 			snprintf(ns, sizeof(ns), "%s+%#0" PRIx64,
506 			    pmcstat_string_unintern(sym->ps_name),
507 			    cg->pcg_func - sym->ps_start);
508 			break;
509 		default:
510 			snprintf(ns, sizeof(ns), "%s",
511 			    pmcstat_string_unintern(sym->ps_name));
512 			break;
513 		}
514 	}
515 
516 	PMCSTAT_ATTRON(v_attrs);
517 	PMCSTAT_PRINTW("%5.5s", vs);
518 	PMCSTAT_ATTROFF(v_attrs);
519 	PMCSTAT_PRINTW(" %-10.10s %-30.30s",
520 	    pmcstat_string_unintern(cg->pcg_image->pi_name),
521 	    ns);
522 
523 	nchildren = cg->pcg_nchildren;
524 	if (nchildren == 0) {
525 		PMCSTAT_PRINTW("\n");
526 		return;
527 	}
528 
529 	width = pmcstat_displaywidth - 40;
530 
531 	if ((sortbuffer = (struct pmcstat_cgnode **)
532 		malloc(sizeof(struct pmcstat_cgnode *) *
533 		    nchildren)) == NULL)
534 		err(EX_OSERR, "ERROR: Cannot print callgraph");
535 	cgn = sortbuffer;
536 
537 	LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
538 	    *cgn++ = pcg;
539 
540 	assert(cgn - sortbuffer == (int)nchildren);
541 
542 	qsort(sortbuffer, nchildren, sizeof(struct pmcstat_cgnode *),
543 	    pmcstat_cgnode_compare);
544 
545 	/* Count how many callers. */
546 	for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
547 		pcg = *cgn;
548 
549 		v = PMCPL_CG_COUNTP(pcg);
550 		if (v < pmcstat_threshold)
551 			break;
552 	}
553 	nchildren = n;
554 
555 	for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
556 		pcg = *cgn;
557 
558 		/* Format value. */
559 		if (nchildren > 1) {
560 			v = PMCPL_CG_COUNTP(pcg);
561 			vs_len = snprintf(vs, sizeof(vs), ":%.1f", v);
562 			v_attrs = PMCSTAT_ATTRPERCENT(v);
563 		} else
564 			vs_len = 0;
565 
566 		/* Format name. */
567 		sym = pmcstat_symbol_search(pcg->pcg_image, pcg->pcg_func);
568 		if (sym != NULL) {
569 			ns_len = snprintf(ns, sizeof(ns), "%s",
570 			    pmcstat_string_unintern(sym->ps_name));
571 		} else
572 			ns_len = snprintf(ns, sizeof(ns), "%p",
573 			    (void *)pcg->pcg_func);
574 
575 		len = ns_len + vs_len + 1;
576 		if (width - len < 0) {
577 			PMCSTAT_PRINTW(" ...");
578 			break;
579 		}
580 		width -= len;
581 
582 		PMCSTAT_PRINTW(" %s", ns);
583 		if (nchildren > 1) {
584 			PMCSTAT_ATTRON(v_attrs);
585 			PMCSTAT_PRINTW("%s", vs);
586 			PMCSTAT_ATTROFF(v_attrs);
587 		}
588 	}
589 	PMCSTAT_PRINTW("\n");
590 	free(sortbuffer);
591 }
592 
593 /*
594  * Top mode display.
595  */
596 
597 void
598 pmcpl_cg_topdisplay(void)
599 {
600 	int n, nentries;
601 	uint32_t nsamples;
602 	struct pmcstat_cgnode **sortbuffer, **cgn;
603 	struct pmcstat_cgnode_hash *pch;
604 	struct pmcstat_pmcrecord *pmcr;
605 
606 	pmcr = pmcstat_pmcindex_to_pmcr(pmcstat_pmcinfilter);
607 	if (!pmcr)
608 		err(EX_SOFTWARE, "ERROR: invalid pmcindex");
609 
610 	/*
611 	 * We pull out all callgraph nodes in the top-level hash table
612 	 * with a matching PMC index.  We then sort these based on the
613 	 * frequency of occurrence.  Each callgraph node is then
614 	 * printed.
615 	 */
616 
617 	nsamples = 0;
618 
619 	if ((sortbuffer = (struct pmcstat_cgnode **)
620 	    malloc(sizeof(struct pmcstat_cgnode *) *
621 	    pmcstat_cgnode_hash_count)) == NULL)
622 		err(EX_OSERR, "ERROR: Cannot sort callgraph");
623 	cgn = sortbuffer;
624 
625 	for (n = 0; n < PMCSTAT_NHASH; n++)
626 		LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
627 		    if (pmcr == NULL || pch->pch_pmcid == pmcr->pr_pmcid) {
628 			    nsamples += pch->pch_cgnode->pcg_count;
629 			    *cgn++ = pch->pch_cgnode;
630 		    }
631 
632 	nentries = cgn - sortbuffer;
633 	assert(nentries <= pmcstat_cgnode_hash_count);
634 
635 	if (nentries == 0) {
636 		free(sortbuffer);
637 		return;
638 	}
639 
640 	qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
641 	    pmcstat_cgnode_compare);
642 
643 	PMCSTAT_PRINTW("%5.5s %-10.10s %-30.30s %s\n",
644 	    "%SAMP", "IMAGE", "FUNCTION", "CALLERS");
645 
646 	nentries = min(pmcstat_displayheight - 2, nentries);
647 
648 	for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
649 		if (PMCPL_CG_COUNTP(*cgn) < pmcstat_threshold)
650 			break;
651 		pmcstat_cgnode_topprint(*cgn, 0, nsamples);
652 	}
653 
654 	free(sortbuffer);
655 }
656 
657 /*
658  * Handle top mode keypress.
659  */
660 
661 int
662 pmcpl_cg_topkeypress(int c, void *arg)
663 {
664 	WINDOW *w;
665 
666 	w = (WINDOW *)arg;
667 
668 	(void) c; (void) w;
669 
670 	return 0;
671 }
672 
673 int
674 pmcpl_cg_init(void)
675 {
676 	int i;
677 
678 	pmcstat_cgnode_hash_count = 0;
679 	pmcstat_previous_filename_printed = NULL;
680 
681 	for (i = 0; i < PMCSTAT_NHASH; i++) {
682 		LIST_INIT(&pmcstat_cgnode_hash[i]);
683 	}
684 
685 	return (0);
686 }
687 
688 void
689 pmcpl_cg_shutdown(FILE *mf)
690 {
691 	int i;
692 	struct pmcstat_cgnode_hash *pch, *pchtmp;
693 
694 	(void) mf;
695 
696 	if (args.pa_flags & FLAG_DO_CALLGRAPHS)
697 		pmcstat_callgraph_print();
698 
699 	/*
700 	 * Free memory.
701 	 */
702 	for (i = 0; i < PMCSTAT_NHASH; i++) {
703 		LIST_FOREACH_SAFE(pch, &pmcstat_cgnode_hash[i], pch_next,
704 		    pchtmp) {
705 			pmcstat_cgnode_free(pch->pch_cgnode);
706 			LIST_REMOVE(pch, pch_next);
707 			free(pch);
708 		}
709 	}
710 }
711 
712