xref: /linux/tools/perf/builtin-kmem.c (revision 8b1935e6a36b0967efc593d67ed3aebbfbc1f5b1)
1 #include "builtin.h"
2 #include "perf.h"
3 
4 #include "util/util.h"
5 #include "util/cache.h"
6 #include "util/symbol.h"
7 #include "util/thread.h"
8 #include "util/header.h"
9 #include "util/session.h"
10 
11 #include "util/parse-options.h"
12 #include "util/trace-event.h"
13 
14 #include "util/debug.h"
15 
16 #include <linux/rbtree.h>
17 
18 struct alloc_stat;
19 typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);
20 
21 static char const		*input_name = "perf.data";
22 
23 static int			alloc_flag;
24 static int			caller_flag;
25 
26 static int			alloc_lines = -1;
27 static int			caller_lines = -1;
28 
29 static bool			raw_ip;
30 
31 static char			default_sort_order[] = "frag,hit,bytes";
32 
33 static int			*cpunode_map;
34 static int			max_cpu_num;
35 
36 struct alloc_stat {
37 	u64	call_site;
38 	u64	ptr;
39 	u64	bytes_req;
40 	u64	bytes_alloc;
41 	u32	hit;
42 	u32	pingpong;
43 
44 	short	alloc_cpu;
45 
46 	struct rb_node node;
47 };
48 
49 static struct rb_root root_alloc_stat;
50 static struct rb_root root_alloc_sorted;
51 static struct rb_root root_caller_stat;
52 static struct rb_root root_caller_sorted;
53 
54 static unsigned long total_requested, total_allocated;
55 static unsigned long nr_allocs, nr_cross_allocs;
56 
57 #define PATH_SYS_NODE	"/sys/devices/system/node"
58 
59 static void init_cpunode_map(void)
60 {
61 	FILE *fp;
62 	int i;
63 
64 	fp = fopen("/sys/devices/system/cpu/kernel_max", "r");
65 	if (!fp) {
66 		max_cpu_num = 4096;
67 		return;
68 	}
69 
70 	if (fscanf(fp, "%d", &max_cpu_num) < 1)
71 		die("Failed to read 'kernel_max' from sysfs");
72 	max_cpu_num++;
73 
74 	cpunode_map = calloc(max_cpu_num, sizeof(int));
75 	if (!cpunode_map)
76 		die("calloc");
77 	for (i = 0; i < max_cpu_num; i++)
78 		cpunode_map[i] = -1;
79 	fclose(fp);
80 }
81 
82 static void setup_cpunode_map(void)
83 {
84 	struct dirent *dent1, *dent2;
85 	DIR *dir1, *dir2;
86 	unsigned int cpu, mem;
87 	char buf[PATH_MAX];
88 
89 	init_cpunode_map();
90 
91 	dir1 = opendir(PATH_SYS_NODE);
92 	if (!dir1)
93 		return;
94 
95 	while ((dent1 = readdir(dir1)) != NULL) {
96 		if (dent1->d_type != DT_DIR ||
97 		    sscanf(dent1->d_name, "node%u", &mem) < 1)
98 			continue;
99 
100 		snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
101 		dir2 = opendir(buf);
102 		if (!dir2)
103 			continue;
104 		while ((dent2 = readdir(dir2)) != NULL) {
105 			if (dent2->d_type != DT_LNK ||
106 			    sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
107 				continue;
108 			cpunode_map[cpu] = mem;
109 		}
110 	}
111 }
112 
113 static void insert_alloc_stat(unsigned long call_site, unsigned long ptr,
114 			      int bytes_req, int bytes_alloc, int cpu)
115 {
116 	struct rb_node **node = &root_alloc_stat.rb_node;
117 	struct rb_node *parent = NULL;
118 	struct alloc_stat *data = NULL;
119 
120 	while (*node) {
121 		parent = *node;
122 		data = rb_entry(*node, struct alloc_stat, node);
123 
124 		if (ptr > data->ptr)
125 			node = &(*node)->rb_right;
126 		else if (ptr < data->ptr)
127 			node = &(*node)->rb_left;
128 		else
129 			break;
130 	}
131 
132 	if (data && data->ptr == ptr) {
133 		data->hit++;
134 		data->bytes_req += bytes_req;
135 		data->bytes_alloc += bytes_alloc;
136 	} else {
137 		data = malloc(sizeof(*data));
138 		if (!data)
139 			die("malloc");
140 		data->ptr = ptr;
141 		data->pingpong = 0;
142 		data->hit = 1;
143 		data->bytes_req = bytes_req;
144 		data->bytes_alloc = bytes_alloc;
145 
146 		rb_link_node(&data->node, parent, node);
147 		rb_insert_color(&data->node, &root_alloc_stat);
148 	}
149 	data->call_site = call_site;
150 	data->alloc_cpu = cpu;
151 }
152 
153 static void insert_caller_stat(unsigned long call_site,
154 			      int bytes_req, int bytes_alloc)
155 {
156 	struct rb_node **node = &root_caller_stat.rb_node;
157 	struct rb_node *parent = NULL;
158 	struct alloc_stat *data = NULL;
159 
160 	while (*node) {
161 		parent = *node;
162 		data = rb_entry(*node, struct alloc_stat, node);
163 
164 		if (call_site > data->call_site)
165 			node = &(*node)->rb_right;
166 		else if (call_site < data->call_site)
167 			node = &(*node)->rb_left;
168 		else
169 			break;
170 	}
171 
172 	if (data && data->call_site == call_site) {
173 		data->hit++;
174 		data->bytes_req += bytes_req;
175 		data->bytes_alloc += bytes_alloc;
176 	} else {
177 		data = malloc(sizeof(*data));
178 		if (!data)
179 			die("malloc");
180 		data->call_site = call_site;
181 		data->pingpong = 0;
182 		data->hit = 1;
183 		data->bytes_req = bytes_req;
184 		data->bytes_alloc = bytes_alloc;
185 
186 		rb_link_node(&data->node, parent, node);
187 		rb_insert_color(&data->node, &root_caller_stat);
188 	}
189 }
190 
191 static void process_alloc_event(void *data,
192 				struct event *event,
193 				int cpu,
194 				u64 timestamp __used,
195 				struct thread *thread __used,
196 				int node)
197 {
198 	unsigned long call_site;
199 	unsigned long ptr;
200 	int bytes_req;
201 	int bytes_alloc;
202 	int node1, node2;
203 
204 	ptr = raw_field_value(event, "ptr", data);
205 	call_site = raw_field_value(event, "call_site", data);
206 	bytes_req = raw_field_value(event, "bytes_req", data);
207 	bytes_alloc = raw_field_value(event, "bytes_alloc", data);
208 
209 	insert_alloc_stat(call_site, ptr, bytes_req, bytes_alloc, cpu);
210 	insert_caller_stat(call_site, bytes_req, bytes_alloc);
211 
212 	total_requested += bytes_req;
213 	total_allocated += bytes_alloc;
214 
215 	if (node) {
216 		node1 = cpunode_map[cpu];
217 		node2 = raw_field_value(event, "node", data);
218 		if (node1 != node2)
219 			nr_cross_allocs++;
220 	}
221 	nr_allocs++;
222 }
223 
224 static int ptr_cmp(struct alloc_stat *, struct alloc_stat *);
225 static int callsite_cmp(struct alloc_stat *, struct alloc_stat *);
226 
227 static struct alloc_stat *search_alloc_stat(unsigned long ptr,
228 					    unsigned long call_site,
229 					    struct rb_root *root,
230 					    sort_fn_t sort_fn)
231 {
232 	struct rb_node *node = root->rb_node;
233 	struct alloc_stat key = { .ptr = ptr, .call_site = call_site };
234 
235 	while (node) {
236 		struct alloc_stat *data;
237 		int cmp;
238 
239 		data = rb_entry(node, struct alloc_stat, node);
240 
241 		cmp = sort_fn(&key, data);
242 		if (cmp < 0)
243 			node = node->rb_left;
244 		else if (cmp > 0)
245 			node = node->rb_right;
246 		else
247 			return data;
248 	}
249 	return NULL;
250 }
251 
252 static void process_free_event(void *data,
253 			       struct event *event,
254 			       int cpu,
255 			       u64 timestamp __used,
256 			       struct thread *thread __used)
257 {
258 	unsigned long ptr;
259 	struct alloc_stat *s_alloc, *s_caller;
260 
261 	ptr = raw_field_value(event, "ptr", data);
262 
263 	s_alloc = search_alloc_stat(ptr, 0, &root_alloc_stat, ptr_cmp);
264 	if (!s_alloc)
265 		return;
266 
267 	if (cpu != s_alloc->alloc_cpu) {
268 		s_alloc->pingpong++;
269 
270 		s_caller = search_alloc_stat(0, s_alloc->call_site,
271 					     &root_caller_stat, callsite_cmp);
272 		assert(s_caller);
273 		s_caller->pingpong++;
274 	}
275 	s_alloc->alloc_cpu = -1;
276 }
277 
278 static void
279 process_raw_event(event_t *raw_event __used, void *data,
280 		  int cpu, u64 timestamp, struct thread *thread)
281 {
282 	struct event *event;
283 	int type;
284 
285 	type = trace_parse_common_type(data);
286 	event = trace_find_event(type);
287 
288 	if (!strcmp(event->name, "kmalloc") ||
289 	    !strcmp(event->name, "kmem_cache_alloc")) {
290 		process_alloc_event(data, event, cpu, timestamp, thread, 0);
291 		return;
292 	}
293 
294 	if (!strcmp(event->name, "kmalloc_node") ||
295 	    !strcmp(event->name, "kmem_cache_alloc_node")) {
296 		process_alloc_event(data, event, cpu, timestamp, thread, 1);
297 		return;
298 	}
299 
300 	if (!strcmp(event->name, "kfree") ||
301 	    !strcmp(event->name, "kmem_cache_free")) {
302 		process_free_event(data, event, cpu, timestamp, thread);
303 		return;
304 	}
305 }
306 
307 static int process_sample_event(event_t *event, struct perf_session *session)
308 {
309 	struct sample_data data;
310 	struct thread *thread;
311 
312 	memset(&data, 0, sizeof(data));
313 	data.time = -1;
314 	data.cpu = -1;
315 	data.period = 1;
316 
317 	event__parse_sample(event, session->sample_type, &data);
318 
319 	dump_printf("(IP, %d): %d/%d: %#Lx period: %Ld\n", event->header.misc,
320 		    data.pid, data.tid, data.ip, data.period);
321 
322 	thread = perf_session__findnew(session, event->ip.pid);
323 	if (thread == NULL) {
324 		pr_debug("problem processing %d event, skipping it.\n",
325 			 event->header.type);
326 		return -1;
327 	}
328 
329 	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
330 
331 	process_raw_event(event, data.raw_data, data.cpu,
332 			  data.time, thread);
333 
334 	return 0;
335 }
336 
337 static struct perf_event_ops event_ops = {
338 	.sample	= process_sample_event,
339 	.comm	= event__process_comm,
340 };
341 
342 static double fragmentation(unsigned long n_req, unsigned long n_alloc)
343 {
344 	if (n_alloc == 0)
345 		return 0.0;
346 	else
347 		return 100.0 - (100.0 * n_req / n_alloc);
348 }
349 
350 static void __print_result(struct rb_root *root, struct perf_session *session,
351 			   int n_lines, int is_caller)
352 {
353 	struct rb_node *next;
354 
355 	printf("%.102s\n", graph_dotted_line);
356 	printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
357 	printf(" Total_alloc/Per | Total_req/Per   | Hit      | Ping-pong | Frag\n");
358 	printf("%.102s\n", graph_dotted_line);
359 
360 	next = rb_first(root);
361 
362 	while (next && n_lines--) {
363 		struct alloc_stat *data = rb_entry(next, struct alloc_stat,
364 						   node);
365 		struct symbol *sym = NULL;
366 		char buf[BUFSIZ];
367 		u64 addr;
368 
369 		if (is_caller) {
370 			addr = data->call_site;
371 			if (!raw_ip)
372 				sym = map_groups__find_function(&session->kmaps, addr, NULL);
373 		} else
374 			addr = data->ptr;
375 
376 		if (sym != NULL)
377 			snprintf(buf, sizeof(buf), "%s+%Lx", sym->name,
378 				 addr - sym->start);
379 		else
380 			snprintf(buf, sizeof(buf), "%#Lx", addr);
381 		printf(" %-34s |", buf);
382 
383 		printf(" %9llu/%-5lu | %9llu/%-5lu | %8lu | %8lu | %6.3f%%\n",
384 		       (unsigned long long)data->bytes_alloc,
385 		       (unsigned long)data->bytes_alloc / data->hit,
386 		       (unsigned long long)data->bytes_req,
387 		       (unsigned long)data->bytes_req / data->hit,
388 		       (unsigned long)data->hit,
389 		       (unsigned long)data->pingpong,
390 		       fragmentation(data->bytes_req, data->bytes_alloc));
391 
392 		next = rb_next(next);
393 	}
394 
395 	if (n_lines == -1)
396 		printf(" ...                                | ...             | ...             | ...    | ...      | ...   \n");
397 
398 	printf("%.102s\n", graph_dotted_line);
399 }
400 
401 static void print_summary(void)
402 {
403 	printf("\nSUMMARY\n=======\n");
404 	printf("Total bytes requested: %lu\n", total_requested);
405 	printf("Total bytes allocated: %lu\n", total_allocated);
406 	printf("Total bytes wasted on internal fragmentation: %lu\n",
407 	       total_allocated - total_requested);
408 	printf("Internal fragmentation: %f%%\n",
409 	       fragmentation(total_requested, total_allocated));
410 	printf("Cross CPU allocations: %lu/%lu\n", nr_cross_allocs, nr_allocs);
411 }
412 
413 static void print_result(struct perf_session *session)
414 {
415 	if (caller_flag)
416 		__print_result(&root_caller_sorted, session, caller_lines, 1);
417 	if (alloc_flag)
418 		__print_result(&root_alloc_sorted, session, alloc_lines, 0);
419 	print_summary();
420 }
421 
422 struct sort_dimension {
423 	const char		name[20];
424 	sort_fn_t		cmp;
425 	struct list_head	list;
426 };
427 
428 static LIST_HEAD(caller_sort);
429 static LIST_HEAD(alloc_sort);
430 
431 static void sort_insert(struct rb_root *root, struct alloc_stat *data,
432 			struct list_head *sort_list)
433 {
434 	struct rb_node **new = &(root->rb_node);
435 	struct rb_node *parent = NULL;
436 	struct sort_dimension *sort;
437 
438 	while (*new) {
439 		struct alloc_stat *this;
440 		int cmp = 0;
441 
442 		this = rb_entry(*new, struct alloc_stat, node);
443 		parent = *new;
444 
445 		list_for_each_entry(sort, sort_list, list) {
446 			cmp = sort->cmp(data, this);
447 			if (cmp)
448 				break;
449 		}
450 
451 		if (cmp > 0)
452 			new = &((*new)->rb_left);
453 		else
454 			new = &((*new)->rb_right);
455 	}
456 
457 	rb_link_node(&data->node, parent, new);
458 	rb_insert_color(&data->node, root);
459 }
460 
461 static void __sort_result(struct rb_root *root, struct rb_root *root_sorted,
462 			  struct list_head *sort_list)
463 {
464 	struct rb_node *node;
465 	struct alloc_stat *data;
466 
467 	for (;;) {
468 		node = rb_first(root);
469 		if (!node)
470 			break;
471 
472 		rb_erase(node, root);
473 		data = rb_entry(node, struct alloc_stat, node);
474 		sort_insert(root_sorted, data, sort_list);
475 	}
476 }
477 
478 static void sort_result(void)
479 {
480 	__sort_result(&root_alloc_stat, &root_alloc_sorted, &alloc_sort);
481 	__sort_result(&root_caller_stat, &root_caller_sorted, &caller_sort);
482 }
483 
484 static int __cmd_kmem(void)
485 {
486 	int err = -EINVAL;
487 	struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
488 	if (session == NULL)
489 		return -ENOMEM;
490 
491 	if (!perf_session__has_traces(session, "kmem record"))
492 		goto out_delete;
493 
494 	setup_pager();
495 	err = perf_session__process_events(session, &event_ops);
496 	if (err != 0)
497 		goto out_delete;
498 	sort_result();
499 	print_result(session);
500 out_delete:
501 	perf_session__delete(session);
502 	return err;
503 }
504 
505 static const char * const kmem_usage[] = {
506 	"perf kmem [<options>] {record|stat}",
507 	NULL
508 };
509 
510 static int ptr_cmp(struct alloc_stat *l, struct alloc_stat *r)
511 {
512 	if (l->ptr < r->ptr)
513 		return -1;
514 	else if (l->ptr > r->ptr)
515 		return 1;
516 	return 0;
517 }
518 
519 static struct sort_dimension ptr_sort_dimension = {
520 	.name	= "ptr",
521 	.cmp	= ptr_cmp,
522 };
523 
524 static int callsite_cmp(struct alloc_stat *l, struct alloc_stat *r)
525 {
526 	if (l->call_site < r->call_site)
527 		return -1;
528 	else if (l->call_site > r->call_site)
529 		return 1;
530 	return 0;
531 }
532 
533 static struct sort_dimension callsite_sort_dimension = {
534 	.name	= "callsite",
535 	.cmp	= callsite_cmp,
536 };
537 
538 static int hit_cmp(struct alloc_stat *l, struct alloc_stat *r)
539 {
540 	if (l->hit < r->hit)
541 		return -1;
542 	else if (l->hit > r->hit)
543 		return 1;
544 	return 0;
545 }
546 
547 static struct sort_dimension hit_sort_dimension = {
548 	.name	= "hit",
549 	.cmp	= hit_cmp,
550 };
551 
552 static int bytes_cmp(struct alloc_stat *l, struct alloc_stat *r)
553 {
554 	if (l->bytes_alloc < r->bytes_alloc)
555 		return -1;
556 	else if (l->bytes_alloc > r->bytes_alloc)
557 		return 1;
558 	return 0;
559 }
560 
561 static struct sort_dimension bytes_sort_dimension = {
562 	.name	= "bytes",
563 	.cmp	= bytes_cmp,
564 };
565 
566 static int frag_cmp(struct alloc_stat *l, struct alloc_stat *r)
567 {
568 	double x, y;
569 
570 	x = fragmentation(l->bytes_req, l->bytes_alloc);
571 	y = fragmentation(r->bytes_req, r->bytes_alloc);
572 
573 	if (x < y)
574 		return -1;
575 	else if (x > y)
576 		return 1;
577 	return 0;
578 }
579 
580 static struct sort_dimension frag_sort_dimension = {
581 	.name	= "frag",
582 	.cmp	= frag_cmp,
583 };
584 
585 static int pingpong_cmp(struct alloc_stat *l, struct alloc_stat *r)
586 {
587 	if (l->pingpong < r->pingpong)
588 		return -1;
589 	else if (l->pingpong > r->pingpong)
590 		return 1;
591 	return 0;
592 }
593 
594 static struct sort_dimension pingpong_sort_dimension = {
595 	.name	= "pingpong",
596 	.cmp	= pingpong_cmp,
597 };
598 
599 static struct sort_dimension *avail_sorts[] = {
600 	&ptr_sort_dimension,
601 	&callsite_sort_dimension,
602 	&hit_sort_dimension,
603 	&bytes_sort_dimension,
604 	&frag_sort_dimension,
605 	&pingpong_sort_dimension,
606 };
607 
608 #define NUM_AVAIL_SORTS	\
609 	(int)(sizeof(avail_sorts) / sizeof(struct sort_dimension *))
610 
611 static int sort_dimension__add(const char *tok, struct list_head *list)
612 {
613 	struct sort_dimension *sort;
614 	int i;
615 
616 	for (i = 0; i < NUM_AVAIL_SORTS; i++) {
617 		if (!strcmp(avail_sorts[i]->name, tok)) {
618 			sort = malloc(sizeof(*sort));
619 			if (!sort)
620 				die("malloc");
621 			memcpy(sort, avail_sorts[i], sizeof(*sort));
622 			list_add_tail(&sort->list, list);
623 			return 0;
624 		}
625 	}
626 
627 	return -1;
628 }
629 
630 static int setup_sorting(struct list_head *sort_list, const char *arg)
631 {
632 	char *tok;
633 	char *str = strdup(arg);
634 
635 	if (!str)
636 		die("strdup");
637 
638 	while (true) {
639 		tok = strsep(&str, ",");
640 		if (!tok)
641 			break;
642 		if (sort_dimension__add(tok, sort_list) < 0) {
643 			error("Unknown --sort key: '%s'", tok);
644 			return -1;
645 		}
646 	}
647 
648 	free(str);
649 	return 0;
650 }
651 
652 static int parse_sort_opt(const struct option *opt __used,
653 			  const char *arg, int unset __used)
654 {
655 	if (!arg)
656 		return -1;
657 
658 	if (caller_flag > alloc_flag)
659 		return setup_sorting(&caller_sort, arg);
660 	else
661 		return setup_sorting(&alloc_sort, arg);
662 
663 	return 0;
664 }
665 
666 static int parse_caller_opt(const struct option *opt __used,
667 			  const char *arg __used, int unset __used)
668 {
669 	caller_flag = (alloc_flag + 1);
670 	return 0;
671 }
672 
673 static int parse_alloc_opt(const struct option *opt __used,
674 			  const char *arg __used, int unset __used)
675 {
676 	alloc_flag = (caller_flag + 1);
677 	return 0;
678 }
679 
680 static int parse_line_opt(const struct option *opt __used,
681 			  const char *arg, int unset __used)
682 {
683 	int lines;
684 
685 	if (!arg)
686 		return -1;
687 
688 	lines = strtoul(arg, NULL, 10);
689 
690 	if (caller_flag > alloc_flag)
691 		caller_lines = lines;
692 	else
693 		alloc_lines = lines;
694 
695 	return 0;
696 }
697 
698 static const struct option kmem_options[] = {
699 	OPT_STRING('i', "input", &input_name, "file",
700 		   "input file name"),
701 	OPT_CALLBACK_NOOPT(0, "caller", NULL, NULL,
702 			   "show per-callsite statistics",
703 			   parse_caller_opt),
704 	OPT_CALLBACK_NOOPT(0, "alloc", NULL, NULL,
705 			   "show per-allocation statistics",
706 			   parse_alloc_opt),
707 	OPT_CALLBACK('s', "sort", NULL, "key[,key2...]",
708 		     "sort by keys: ptr, call_site, bytes, hit, pingpong, frag",
709 		     parse_sort_opt),
710 	OPT_CALLBACK('l', "line", NULL, "num",
711 		     "show n lines",
712 		     parse_line_opt),
713 	OPT_BOOLEAN(0, "raw-ip", &raw_ip, "show raw ip instead of symbol"),
714 	OPT_END()
715 };
716 
717 static const char *record_args[] = {
718 	"record",
719 	"-a",
720 	"-R",
721 	"-M",
722 	"-f",
723 	"-c", "1",
724 	"-e", "kmem:kmalloc",
725 	"-e", "kmem:kmalloc_node",
726 	"-e", "kmem:kfree",
727 	"-e", "kmem:kmem_cache_alloc",
728 	"-e", "kmem:kmem_cache_alloc_node",
729 	"-e", "kmem:kmem_cache_free",
730 };
731 
732 static int __cmd_record(int argc, const char **argv)
733 {
734 	unsigned int rec_argc, i, j;
735 	const char **rec_argv;
736 
737 	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
738 	rec_argv = calloc(rec_argc + 1, sizeof(char *));
739 
740 	for (i = 0; i < ARRAY_SIZE(record_args); i++)
741 		rec_argv[i] = strdup(record_args[i]);
742 
743 	for (j = 1; j < (unsigned int)argc; j++, i++)
744 		rec_argv[i] = argv[j];
745 
746 	return cmd_record(i, rec_argv, NULL);
747 }
748 
749 int cmd_kmem(int argc, const char **argv, const char *prefix __used)
750 {
751 	argc = parse_options(argc, argv, kmem_options, kmem_usage, 0);
752 
753 	if (!argc)
754 		usage_with_options(kmem_usage, kmem_options);
755 
756 	symbol__init();
757 
758 	if (!strncmp(argv[0], "rec", 3)) {
759 		return __cmd_record(argc, argv);
760 	} else if (!strcmp(argv[0], "stat")) {
761 		setup_cpunode_map();
762 
763 		if (list_empty(&caller_sort))
764 			setup_sorting(&caller_sort, default_sort_order);
765 		if (list_empty(&alloc_sort))
766 			setup_sorting(&alloc_sort, default_sort_order);
767 
768 		return __cmd_kmem();
769 	} else
770 		usage_with_options(kmem_usage, kmem_options);
771 
772 	return 0;
773 }
774 
775