xref: /linux/mm/damon/sysfs-schemes.c (revision c8faf11cd192214e231626c3ee973a35d8fc33f2)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DAMON sysfs Interface
4  *
5  * Copyright (c) 2022 SeongJae Park <sj@kernel.org>
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/numa.h>
10 
11 #include "sysfs-common.h"
12 
13 /*
14  * scheme region directory
15  */
16 
17 struct damon_sysfs_scheme_region {
18 	struct kobject kobj;
19 	struct damon_addr_range ar;
20 	unsigned int nr_accesses;
21 	unsigned int age;
22 	struct list_head list;
23 };
24 
25 static struct damon_sysfs_scheme_region *damon_sysfs_scheme_region_alloc(
26 		struct damon_region *region)
27 {
28 	struct damon_sysfs_scheme_region *sysfs_region = kmalloc(
29 			sizeof(*sysfs_region), GFP_KERNEL);
30 
31 	if (!sysfs_region)
32 		return NULL;
33 	sysfs_region->kobj = (struct kobject){};
34 	sysfs_region->ar = region->ar;
35 	sysfs_region->nr_accesses = region->nr_accesses_bp / 10000;
36 	sysfs_region->age = region->age;
37 	INIT_LIST_HEAD(&sysfs_region->list);
38 	return sysfs_region;
39 }
40 
41 static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
42 		char *buf)
43 {
44 	struct damon_sysfs_scheme_region *region = container_of(kobj,
45 			struct damon_sysfs_scheme_region, kobj);
46 
47 	return sysfs_emit(buf, "%lu\n", region->ar.start);
48 }
49 
50 static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
51 		char *buf)
52 {
53 	struct damon_sysfs_scheme_region *region = container_of(kobj,
54 			struct damon_sysfs_scheme_region, kobj);
55 
56 	return sysfs_emit(buf, "%lu\n", region->ar.end);
57 }
58 
59 static ssize_t nr_accesses_show(struct kobject *kobj,
60 		struct kobj_attribute *attr, char *buf)
61 {
62 	struct damon_sysfs_scheme_region *region = container_of(kobj,
63 			struct damon_sysfs_scheme_region, kobj);
64 
65 	return sysfs_emit(buf, "%u\n", region->nr_accesses);
66 }
67 
68 static ssize_t age_show(struct kobject *kobj, struct kobj_attribute *attr,
69 		char *buf)
70 {
71 	struct damon_sysfs_scheme_region *region = container_of(kobj,
72 			struct damon_sysfs_scheme_region, kobj);
73 
74 	return sysfs_emit(buf, "%u\n", region->age);
75 }
76 
77 static void damon_sysfs_scheme_region_release(struct kobject *kobj)
78 {
79 	struct damon_sysfs_scheme_region *region = container_of(kobj,
80 			struct damon_sysfs_scheme_region, kobj);
81 
82 	list_del(&region->list);
83 	kfree(region);
84 }
85 
86 static struct kobj_attribute damon_sysfs_scheme_region_start_attr =
87 		__ATTR_RO_MODE(start, 0400);
88 
89 static struct kobj_attribute damon_sysfs_scheme_region_end_attr =
90 		__ATTR_RO_MODE(end, 0400);
91 
92 static struct kobj_attribute damon_sysfs_scheme_region_nr_accesses_attr =
93 		__ATTR_RO_MODE(nr_accesses, 0400);
94 
95 static struct kobj_attribute damon_sysfs_scheme_region_age_attr =
96 		__ATTR_RO_MODE(age, 0400);
97 
98 static struct attribute *damon_sysfs_scheme_region_attrs[] = {
99 	&damon_sysfs_scheme_region_start_attr.attr,
100 	&damon_sysfs_scheme_region_end_attr.attr,
101 	&damon_sysfs_scheme_region_nr_accesses_attr.attr,
102 	&damon_sysfs_scheme_region_age_attr.attr,
103 	NULL,
104 };
105 ATTRIBUTE_GROUPS(damon_sysfs_scheme_region);
106 
107 static const struct kobj_type damon_sysfs_scheme_region_ktype = {
108 	.release = damon_sysfs_scheme_region_release,
109 	.sysfs_ops = &kobj_sysfs_ops,
110 	.default_groups = damon_sysfs_scheme_region_groups,
111 };
112 
113 /*
114  * scheme regions directory
115  */
116 
117 /*
118  * enum damos_sysfs_regions_upd_status - Represent DAMOS tried regions update
119  *					 status
120  * @DAMOS_TRIED_REGIONS_UPD_IDLE:		Waiting for next request.
121  * @DAMOS_TRIED_REGIONS_UPD_STARTED:		Update started.
122  * @DAMOS_TRIED_REGIONS_UPD_FINISHED:	Update finished.
123  *
124  * Each DAMON-based operation scheme (&struct damos) has its own apply
125  * interval, and we need to expose the scheme tried regions based on only
126  * single snapshot.  For this, we keep the tried regions update status for each
127  * scheme.  The status becomes 'idle' at the beginning.
128  *
129  * Once the tried regions update request is received, the request handling
130  * start function (damon_sysfs_scheme_update_regions_start()) sets the status
131  * of all schemes as 'idle' again, and register ->before_damos_apply()
132  * callback.
133  *
134  * Then, the first followup ->before_damos_apply() callback
135  * (damon_sysfs_before_damos_apply()) sets the status 'started'.  The first
136  * ->after_sampling() or ->after_aggregation() callback
137  *  (damon_sysfs_cmd_request_callback()) after the call is called only after
138  *  the scheme is completely applied to the given snapshot.  Hence the callback
139  *  knows the situation by showing 'started' status, and sets the status as
140  *  'finished'.  Then, damon_sysfs_before_damos_apply() understands the
141  *  situation by showing the 'finished' status and do nothing.
142  *
143  * If DAMOS is not applied to any region due to any reasons including the
144  * access pattern, the watermarks, the quotas, and the filters,
145  * ->before_damos_apply() will not be called back.  Until the situation is
146  * changed, the update will not be finished.  To avoid this,
147  * damon_sysfs_after_sampling() set the status as 'finished' if more than two
148  * apply intervals of the scheme is passed while the state is 'idle'.
149  *
150  *  Finally, the tried regions request handling finisher function
151  *  (damon_sysfs_schemes_update_regions_stop()) unregisters the callbacks.
152  */
153 enum damos_sysfs_regions_upd_status {
154 	DAMOS_TRIED_REGIONS_UPD_IDLE,
155 	DAMOS_TRIED_REGIONS_UPD_STARTED,
156 	DAMOS_TRIED_REGIONS_UPD_FINISHED,
157 };
158 
159 struct damon_sysfs_scheme_regions {
160 	struct kobject kobj;
161 	struct list_head regions_list;
162 	int nr_regions;
163 	unsigned long total_bytes;
164 	enum damos_sysfs_regions_upd_status upd_status;
165 	unsigned long upd_timeout_jiffies;
166 };
167 
168 static struct damon_sysfs_scheme_regions *
169 damon_sysfs_scheme_regions_alloc(void)
170 {
171 	struct damon_sysfs_scheme_regions *regions = kmalloc(sizeof(*regions),
172 			GFP_KERNEL);
173 
174 	if (!regions)
175 		return NULL;
176 
177 	regions->kobj = (struct kobject){};
178 	INIT_LIST_HEAD(&regions->regions_list);
179 	regions->nr_regions = 0;
180 	regions->total_bytes = 0;
181 	regions->upd_status = DAMOS_TRIED_REGIONS_UPD_IDLE;
182 	return regions;
183 }
184 
185 static ssize_t total_bytes_show(struct kobject *kobj,
186 		struct kobj_attribute *attr, char *buf)
187 {
188 	struct damon_sysfs_scheme_regions *regions = container_of(kobj,
189 			struct damon_sysfs_scheme_regions, kobj);
190 
191 	return sysfs_emit(buf, "%lu\n", regions->total_bytes);
192 }
193 
194 static void damon_sysfs_scheme_regions_rm_dirs(
195 		struct damon_sysfs_scheme_regions *regions)
196 {
197 	struct damon_sysfs_scheme_region *r, *next;
198 
199 	list_for_each_entry_safe(r, next, &regions->regions_list, list) {
200 		/* release function deletes it from the list */
201 		kobject_put(&r->kobj);
202 		regions->nr_regions--;
203 	}
204 }
205 
206 static void damon_sysfs_scheme_regions_release(struct kobject *kobj)
207 {
208 	kfree(container_of(kobj, struct damon_sysfs_scheme_regions, kobj));
209 }
210 
211 static struct kobj_attribute damon_sysfs_scheme_regions_total_bytes_attr =
212 		__ATTR_RO_MODE(total_bytes, 0400);
213 
214 static struct attribute *damon_sysfs_scheme_regions_attrs[] = {
215 	&damon_sysfs_scheme_regions_total_bytes_attr.attr,
216 	NULL,
217 };
218 ATTRIBUTE_GROUPS(damon_sysfs_scheme_regions);
219 
220 static const struct kobj_type damon_sysfs_scheme_regions_ktype = {
221 	.release = damon_sysfs_scheme_regions_release,
222 	.sysfs_ops = &kobj_sysfs_ops,
223 	.default_groups = damon_sysfs_scheme_regions_groups,
224 };
225 
226 /*
227  * schemes/stats directory
228  */
229 
230 struct damon_sysfs_stats {
231 	struct kobject kobj;
232 	unsigned long nr_tried;
233 	unsigned long sz_tried;
234 	unsigned long nr_applied;
235 	unsigned long sz_applied;
236 	unsigned long qt_exceeds;
237 };
238 
239 static struct damon_sysfs_stats *damon_sysfs_stats_alloc(void)
240 {
241 	return kzalloc(sizeof(struct damon_sysfs_stats), GFP_KERNEL);
242 }
243 
244 static ssize_t nr_tried_show(struct kobject *kobj, struct kobj_attribute *attr,
245 		char *buf)
246 {
247 	struct damon_sysfs_stats *stats = container_of(kobj,
248 			struct damon_sysfs_stats, kobj);
249 
250 	return sysfs_emit(buf, "%lu\n", stats->nr_tried);
251 }
252 
253 static ssize_t sz_tried_show(struct kobject *kobj, struct kobj_attribute *attr,
254 		char *buf)
255 {
256 	struct damon_sysfs_stats *stats = container_of(kobj,
257 			struct damon_sysfs_stats, kobj);
258 
259 	return sysfs_emit(buf, "%lu\n", stats->sz_tried);
260 }
261 
262 static ssize_t nr_applied_show(struct kobject *kobj,
263 		struct kobj_attribute *attr, char *buf)
264 {
265 	struct damon_sysfs_stats *stats = container_of(kobj,
266 			struct damon_sysfs_stats, kobj);
267 
268 	return sysfs_emit(buf, "%lu\n", stats->nr_applied);
269 }
270 
271 static ssize_t sz_applied_show(struct kobject *kobj,
272 		struct kobj_attribute *attr, char *buf)
273 {
274 	struct damon_sysfs_stats *stats = container_of(kobj,
275 			struct damon_sysfs_stats, kobj);
276 
277 	return sysfs_emit(buf, "%lu\n", stats->sz_applied);
278 }
279 
280 static ssize_t qt_exceeds_show(struct kobject *kobj,
281 		struct kobj_attribute *attr, char *buf)
282 {
283 	struct damon_sysfs_stats *stats = container_of(kobj,
284 			struct damon_sysfs_stats, kobj);
285 
286 	return sysfs_emit(buf, "%lu\n", stats->qt_exceeds);
287 }
288 
289 static void damon_sysfs_stats_release(struct kobject *kobj)
290 {
291 	kfree(container_of(kobj, struct damon_sysfs_stats, kobj));
292 }
293 
294 static struct kobj_attribute damon_sysfs_stats_nr_tried_attr =
295 		__ATTR_RO_MODE(nr_tried, 0400);
296 
297 static struct kobj_attribute damon_sysfs_stats_sz_tried_attr =
298 		__ATTR_RO_MODE(sz_tried, 0400);
299 
300 static struct kobj_attribute damon_sysfs_stats_nr_applied_attr =
301 		__ATTR_RO_MODE(nr_applied, 0400);
302 
303 static struct kobj_attribute damon_sysfs_stats_sz_applied_attr =
304 		__ATTR_RO_MODE(sz_applied, 0400);
305 
306 static struct kobj_attribute damon_sysfs_stats_qt_exceeds_attr =
307 		__ATTR_RO_MODE(qt_exceeds, 0400);
308 
309 static struct attribute *damon_sysfs_stats_attrs[] = {
310 	&damon_sysfs_stats_nr_tried_attr.attr,
311 	&damon_sysfs_stats_sz_tried_attr.attr,
312 	&damon_sysfs_stats_nr_applied_attr.attr,
313 	&damon_sysfs_stats_sz_applied_attr.attr,
314 	&damon_sysfs_stats_qt_exceeds_attr.attr,
315 	NULL,
316 };
317 ATTRIBUTE_GROUPS(damon_sysfs_stats);
318 
319 static const struct kobj_type damon_sysfs_stats_ktype = {
320 	.release = damon_sysfs_stats_release,
321 	.sysfs_ops = &kobj_sysfs_ops,
322 	.default_groups = damon_sysfs_stats_groups,
323 };
324 
325 /*
326  * filter directory
327  */
328 
329 struct damon_sysfs_scheme_filter {
330 	struct kobject kobj;
331 	enum damos_filter_type type;
332 	bool matching;
333 	char *memcg_path;
334 	struct damon_addr_range addr_range;
335 	int target_idx;
336 };
337 
338 static struct damon_sysfs_scheme_filter *damon_sysfs_scheme_filter_alloc(void)
339 {
340 	return kzalloc(sizeof(struct damon_sysfs_scheme_filter), GFP_KERNEL);
341 }
342 
343 /* Should match with enum damos_filter_type */
344 static const char * const damon_sysfs_scheme_filter_type_strs[] = {
345 	"anon",
346 	"memcg",
347 	"young",
348 	"addr",
349 	"target",
350 };
351 
352 static ssize_t type_show(struct kobject *kobj,
353 		struct kobj_attribute *attr, char *buf)
354 {
355 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
356 			struct damon_sysfs_scheme_filter, kobj);
357 
358 	return sysfs_emit(buf, "%s\n",
359 			damon_sysfs_scheme_filter_type_strs[filter->type]);
360 }
361 
362 static ssize_t type_store(struct kobject *kobj,
363 		struct kobj_attribute *attr, const char *buf, size_t count)
364 {
365 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
366 			struct damon_sysfs_scheme_filter, kobj);
367 	enum damos_filter_type type;
368 	ssize_t ret = -EINVAL;
369 
370 	for (type = 0; type < NR_DAMOS_FILTER_TYPES; type++) {
371 		if (sysfs_streq(buf, damon_sysfs_scheme_filter_type_strs[
372 					type])) {
373 			filter->type = type;
374 			ret = count;
375 			break;
376 		}
377 	}
378 	return ret;
379 }
380 
381 static ssize_t matching_show(struct kobject *kobj,
382 		struct kobj_attribute *attr, char *buf)
383 {
384 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
385 			struct damon_sysfs_scheme_filter, kobj);
386 
387 	return sysfs_emit(buf, "%c\n", filter->matching ? 'Y' : 'N');
388 }
389 
390 static ssize_t matching_store(struct kobject *kobj,
391 		struct kobj_attribute *attr, const char *buf, size_t count)
392 {
393 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
394 			struct damon_sysfs_scheme_filter, kobj);
395 	bool matching;
396 	int err = kstrtobool(buf, &matching);
397 
398 	if (err)
399 		return err;
400 
401 	filter->matching = matching;
402 	return count;
403 }
404 
405 static ssize_t memcg_path_show(struct kobject *kobj,
406 		struct kobj_attribute *attr, char *buf)
407 {
408 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
409 			struct damon_sysfs_scheme_filter, kobj);
410 
411 	return sysfs_emit(buf, "%s\n",
412 			filter->memcg_path ? filter->memcg_path : "");
413 }
414 
415 static ssize_t memcg_path_store(struct kobject *kobj,
416 		struct kobj_attribute *attr, const char *buf, size_t count)
417 {
418 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
419 			struct damon_sysfs_scheme_filter, kobj);
420 	char *path = kmalloc(sizeof(*path) * (count + 1), GFP_KERNEL);
421 
422 	if (!path)
423 		return -ENOMEM;
424 
425 	strscpy(path, buf, count + 1);
426 	filter->memcg_path = path;
427 	return count;
428 }
429 
430 static ssize_t addr_start_show(struct kobject *kobj,
431 		struct kobj_attribute *attr, char *buf)
432 {
433 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
434 			struct damon_sysfs_scheme_filter, kobj);
435 
436 	return sysfs_emit(buf, "%lu\n", filter->addr_range.start);
437 }
438 
439 static ssize_t addr_start_store(struct kobject *kobj,
440 		struct kobj_attribute *attr, const char *buf, size_t count)
441 {
442 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
443 			struct damon_sysfs_scheme_filter, kobj);
444 	int err = kstrtoul(buf, 0, &filter->addr_range.start);
445 
446 	return err ? err : count;
447 }
448 
449 static ssize_t addr_end_show(struct kobject *kobj,
450 		struct kobj_attribute *attr, char *buf)
451 {
452 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
453 			struct damon_sysfs_scheme_filter, kobj);
454 
455 	return sysfs_emit(buf, "%lu\n", filter->addr_range.end);
456 }
457 
458 static ssize_t addr_end_store(struct kobject *kobj,
459 		struct kobj_attribute *attr, const char *buf, size_t count)
460 {
461 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
462 			struct damon_sysfs_scheme_filter, kobj);
463 	int err = kstrtoul(buf, 0, &filter->addr_range.end);
464 
465 	return err ? err : count;
466 }
467 
468 static ssize_t damon_target_idx_show(struct kobject *kobj,
469 		struct kobj_attribute *attr, char *buf)
470 {
471 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
472 			struct damon_sysfs_scheme_filter, kobj);
473 
474 	return sysfs_emit(buf, "%d\n", filter->target_idx);
475 }
476 
477 static ssize_t damon_target_idx_store(struct kobject *kobj,
478 		struct kobj_attribute *attr, const char *buf, size_t count)
479 {
480 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
481 			struct damon_sysfs_scheme_filter, kobj);
482 	int err = kstrtoint(buf, 0, &filter->target_idx);
483 
484 	return err ? err : count;
485 }
486 
487 static void damon_sysfs_scheme_filter_release(struct kobject *kobj)
488 {
489 	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
490 			struct damon_sysfs_scheme_filter, kobj);
491 
492 	kfree(filter->memcg_path);
493 	kfree(filter);
494 }
495 
496 static struct kobj_attribute damon_sysfs_scheme_filter_type_attr =
497 		__ATTR_RW_MODE(type, 0600);
498 
499 static struct kobj_attribute damon_sysfs_scheme_filter_matching_attr =
500 		__ATTR_RW_MODE(matching, 0600);
501 
502 static struct kobj_attribute damon_sysfs_scheme_filter_memcg_path_attr =
503 		__ATTR_RW_MODE(memcg_path, 0600);
504 
505 static struct kobj_attribute damon_sysfs_scheme_filter_addr_start_attr =
506 		__ATTR_RW_MODE(addr_start, 0600);
507 
508 static struct kobj_attribute damon_sysfs_scheme_filter_addr_end_attr =
509 		__ATTR_RW_MODE(addr_end, 0600);
510 
511 static struct kobj_attribute damon_sysfs_scheme_filter_damon_target_idx_attr =
512 		__ATTR_RW_MODE(damon_target_idx, 0600);
513 
514 static struct attribute *damon_sysfs_scheme_filter_attrs[] = {
515 	&damon_sysfs_scheme_filter_type_attr.attr,
516 	&damon_sysfs_scheme_filter_matching_attr.attr,
517 	&damon_sysfs_scheme_filter_memcg_path_attr.attr,
518 	&damon_sysfs_scheme_filter_addr_start_attr.attr,
519 	&damon_sysfs_scheme_filter_addr_end_attr.attr,
520 	&damon_sysfs_scheme_filter_damon_target_idx_attr.attr,
521 	NULL,
522 };
523 ATTRIBUTE_GROUPS(damon_sysfs_scheme_filter);
524 
525 static const struct kobj_type damon_sysfs_scheme_filter_ktype = {
526 	.release = damon_sysfs_scheme_filter_release,
527 	.sysfs_ops = &kobj_sysfs_ops,
528 	.default_groups = damon_sysfs_scheme_filter_groups,
529 };
530 
531 /*
532  * filters directory
533  */
534 
535 struct damon_sysfs_scheme_filters {
536 	struct kobject kobj;
537 	struct damon_sysfs_scheme_filter **filters_arr;
538 	int nr;
539 };
540 
541 static struct damon_sysfs_scheme_filters *
542 damon_sysfs_scheme_filters_alloc(void)
543 {
544 	return kzalloc(sizeof(struct damon_sysfs_scheme_filters), GFP_KERNEL);
545 }
546 
547 static void damon_sysfs_scheme_filters_rm_dirs(
548 		struct damon_sysfs_scheme_filters *filters)
549 {
550 	struct damon_sysfs_scheme_filter **filters_arr = filters->filters_arr;
551 	int i;
552 
553 	for (i = 0; i < filters->nr; i++)
554 		kobject_put(&filters_arr[i]->kobj);
555 	filters->nr = 0;
556 	kfree(filters_arr);
557 	filters->filters_arr = NULL;
558 }
559 
560 static int damon_sysfs_scheme_filters_add_dirs(
561 		struct damon_sysfs_scheme_filters *filters, int nr_filters)
562 {
563 	struct damon_sysfs_scheme_filter **filters_arr, *filter;
564 	int err, i;
565 
566 	damon_sysfs_scheme_filters_rm_dirs(filters);
567 	if (!nr_filters)
568 		return 0;
569 
570 	filters_arr = kmalloc_array(nr_filters, sizeof(*filters_arr),
571 			GFP_KERNEL | __GFP_NOWARN);
572 	if (!filters_arr)
573 		return -ENOMEM;
574 	filters->filters_arr = filters_arr;
575 
576 	for (i = 0; i < nr_filters; i++) {
577 		filter = damon_sysfs_scheme_filter_alloc();
578 		if (!filter) {
579 			damon_sysfs_scheme_filters_rm_dirs(filters);
580 			return -ENOMEM;
581 		}
582 
583 		err = kobject_init_and_add(&filter->kobj,
584 				&damon_sysfs_scheme_filter_ktype,
585 				&filters->kobj, "%d", i);
586 		if (err) {
587 			kobject_put(&filter->kobj);
588 			damon_sysfs_scheme_filters_rm_dirs(filters);
589 			return err;
590 		}
591 
592 		filters_arr[i] = filter;
593 		filters->nr++;
594 	}
595 	return 0;
596 }
597 
598 static ssize_t nr_filters_show(struct kobject *kobj,
599 		struct kobj_attribute *attr, char *buf)
600 {
601 	struct damon_sysfs_scheme_filters *filters = container_of(kobj,
602 			struct damon_sysfs_scheme_filters, kobj);
603 
604 	return sysfs_emit(buf, "%d\n", filters->nr);
605 }
606 
607 static ssize_t nr_filters_store(struct kobject *kobj,
608 		struct kobj_attribute *attr, const char *buf, size_t count)
609 {
610 	struct damon_sysfs_scheme_filters *filters;
611 	int nr, err = kstrtoint(buf, 0, &nr);
612 
613 	if (err)
614 		return err;
615 	if (nr < 0)
616 		return -EINVAL;
617 
618 	filters = container_of(kobj, struct damon_sysfs_scheme_filters, kobj);
619 
620 	if (!mutex_trylock(&damon_sysfs_lock))
621 		return -EBUSY;
622 	err = damon_sysfs_scheme_filters_add_dirs(filters, nr);
623 	mutex_unlock(&damon_sysfs_lock);
624 	if (err)
625 		return err;
626 
627 	return count;
628 }
629 
630 static void damon_sysfs_scheme_filters_release(struct kobject *kobj)
631 {
632 	kfree(container_of(kobj, struct damon_sysfs_scheme_filters, kobj));
633 }
634 
635 static struct kobj_attribute damon_sysfs_scheme_filters_nr_attr =
636 		__ATTR_RW_MODE(nr_filters, 0600);
637 
638 static struct attribute *damon_sysfs_scheme_filters_attrs[] = {
639 	&damon_sysfs_scheme_filters_nr_attr.attr,
640 	NULL,
641 };
642 ATTRIBUTE_GROUPS(damon_sysfs_scheme_filters);
643 
644 static const struct kobj_type damon_sysfs_scheme_filters_ktype = {
645 	.release = damon_sysfs_scheme_filters_release,
646 	.sysfs_ops = &kobj_sysfs_ops,
647 	.default_groups = damon_sysfs_scheme_filters_groups,
648 };
649 
650 /*
651  * watermarks directory
652  */
653 
654 struct damon_sysfs_watermarks {
655 	struct kobject kobj;
656 	enum damos_wmark_metric metric;
657 	unsigned long interval_us;
658 	unsigned long high;
659 	unsigned long mid;
660 	unsigned long low;
661 };
662 
663 static struct damon_sysfs_watermarks *damon_sysfs_watermarks_alloc(
664 		enum damos_wmark_metric metric, unsigned long interval_us,
665 		unsigned long high, unsigned long mid, unsigned long low)
666 {
667 	struct damon_sysfs_watermarks *watermarks = kmalloc(
668 			sizeof(*watermarks), GFP_KERNEL);
669 
670 	if (!watermarks)
671 		return NULL;
672 	watermarks->kobj = (struct kobject){};
673 	watermarks->metric = metric;
674 	watermarks->interval_us = interval_us;
675 	watermarks->high = high;
676 	watermarks->mid = mid;
677 	watermarks->low = low;
678 	return watermarks;
679 }
680 
681 /* Should match with enum damos_wmark_metric */
682 static const char * const damon_sysfs_wmark_metric_strs[] = {
683 	"none",
684 	"free_mem_rate",
685 };
686 
687 static ssize_t metric_show(struct kobject *kobj, struct kobj_attribute *attr,
688 		char *buf)
689 {
690 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
691 			struct damon_sysfs_watermarks, kobj);
692 
693 	return sysfs_emit(buf, "%s\n",
694 			damon_sysfs_wmark_metric_strs[watermarks->metric]);
695 }
696 
697 static ssize_t metric_store(struct kobject *kobj, struct kobj_attribute *attr,
698 		const char *buf, size_t count)
699 {
700 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
701 			struct damon_sysfs_watermarks, kobj);
702 	enum damos_wmark_metric metric;
703 
704 	for (metric = 0; metric < NR_DAMOS_WMARK_METRICS; metric++) {
705 		if (sysfs_streq(buf, damon_sysfs_wmark_metric_strs[metric])) {
706 			watermarks->metric = metric;
707 			return count;
708 		}
709 	}
710 	return -EINVAL;
711 }
712 
713 static ssize_t interval_us_show(struct kobject *kobj,
714 		struct kobj_attribute *attr, char *buf)
715 {
716 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
717 			struct damon_sysfs_watermarks, kobj);
718 
719 	return sysfs_emit(buf, "%lu\n", watermarks->interval_us);
720 }
721 
722 static ssize_t interval_us_store(struct kobject *kobj,
723 		struct kobj_attribute *attr, const char *buf, size_t count)
724 {
725 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
726 			struct damon_sysfs_watermarks, kobj);
727 	int err = kstrtoul(buf, 0, &watermarks->interval_us);
728 
729 	return err ? err : count;
730 }
731 
732 static ssize_t high_show(struct kobject *kobj,
733 		struct kobj_attribute *attr, char *buf)
734 {
735 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
736 			struct damon_sysfs_watermarks, kobj);
737 
738 	return sysfs_emit(buf, "%lu\n", watermarks->high);
739 }
740 
741 static ssize_t high_store(struct kobject *kobj,
742 		struct kobj_attribute *attr, const char *buf, size_t count)
743 {
744 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
745 			struct damon_sysfs_watermarks, kobj);
746 	int err = kstrtoul(buf, 0, &watermarks->high);
747 
748 	return err ? err : count;
749 }
750 
751 static ssize_t mid_show(struct kobject *kobj,
752 		struct kobj_attribute *attr, char *buf)
753 {
754 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
755 			struct damon_sysfs_watermarks, kobj);
756 
757 	return sysfs_emit(buf, "%lu\n", watermarks->mid);
758 }
759 
760 static ssize_t mid_store(struct kobject *kobj,
761 		struct kobj_attribute *attr, const char *buf, size_t count)
762 {
763 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
764 			struct damon_sysfs_watermarks, kobj);
765 	int err = kstrtoul(buf, 0, &watermarks->mid);
766 
767 	return err ? err : count;
768 }
769 
770 static ssize_t low_show(struct kobject *kobj,
771 		struct kobj_attribute *attr, char *buf)
772 {
773 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
774 			struct damon_sysfs_watermarks, kobj);
775 
776 	return sysfs_emit(buf, "%lu\n", watermarks->low);
777 }
778 
779 static ssize_t low_store(struct kobject *kobj,
780 		struct kobj_attribute *attr, const char *buf, size_t count)
781 {
782 	struct damon_sysfs_watermarks *watermarks = container_of(kobj,
783 			struct damon_sysfs_watermarks, kobj);
784 	int err = kstrtoul(buf, 0, &watermarks->low);
785 
786 	return err ? err : count;
787 }
788 
789 static void damon_sysfs_watermarks_release(struct kobject *kobj)
790 {
791 	kfree(container_of(kobj, struct damon_sysfs_watermarks, kobj));
792 }
793 
794 static struct kobj_attribute damon_sysfs_watermarks_metric_attr =
795 		__ATTR_RW_MODE(metric, 0600);
796 
797 static struct kobj_attribute damon_sysfs_watermarks_interval_us_attr =
798 		__ATTR_RW_MODE(interval_us, 0600);
799 
800 static struct kobj_attribute damon_sysfs_watermarks_high_attr =
801 		__ATTR_RW_MODE(high, 0600);
802 
803 static struct kobj_attribute damon_sysfs_watermarks_mid_attr =
804 		__ATTR_RW_MODE(mid, 0600);
805 
806 static struct kobj_attribute damon_sysfs_watermarks_low_attr =
807 		__ATTR_RW_MODE(low, 0600);
808 
809 static struct attribute *damon_sysfs_watermarks_attrs[] = {
810 	&damon_sysfs_watermarks_metric_attr.attr,
811 	&damon_sysfs_watermarks_interval_us_attr.attr,
812 	&damon_sysfs_watermarks_high_attr.attr,
813 	&damon_sysfs_watermarks_mid_attr.attr,
814 	&damon_sysfs_watermarks_low_attr.attr,
815 	NULL,
816 };
817 ATTRIBUTE_GROUPS(damon_sysfs_watermarks);
818 
819 static const struct kobj_type damon_sysfs_watermarks_ktype = {
820 	.release = damon_sysfs_watermarks_release,
821 	.sysfs_ops = &kobj_sysfs_ops,
822 	.default_groups = damon_sysfs_watermarks_groups,
823 };
824 
825 /*
826  * quota goal directory
827  */
828 
829 struct damos_sysfs_quota_goal {
830 	struct kobject kobj;
831 	enum damos_quota_goal_metric metric;
832 	unsigned long target_value;
833 	unsigned long current_value;
834 };
835 
836 /* This should match with enum damos_action */
837 static const char * const damos_sysfs_quota_goal_metric_strs[] = {
838 	"user_input",
839 	"some_mem_psi_us",
840 };
841 
842 static struct damos_sysfs_quota_goal *damos_sysfs_quota_goal_alloc(void)
843 {
844 	return kzalloc(sizeof(struct damos_sysfs_quota_goal), GFP_KERNEL);
845 }
846 
847 static ssize_t target_metric_show(struct kobject *kobj,
848 		struct kobj_attribute *attr, char *buf)
849 {
850 	struct damos_sysfs_quota_goal *goal = container_of(kobj,
851 			struct damos_sysfs_quota_goal, kobj);
852 
853 	return sysfs_emit(buf, "%s\n",
854 			damos_sysfs_quota_goal_metric_strs[goal->metric]);
855 }
856 
857 static ssize_t target_metric_store(struct kobject *kobj,
858 		struct kobj_attribute *attr, const char *buf, size_t count)
859 {
860 	struct damos_sysfs_quota_goal *goal = container_of(kobj,
861 			struct damos_sysfs_quota_goal, kobj);
862 	enum damos_quota_goal_metric m;
863 
864 	for (m = 0; m < NR_DAMOS_QUOTA_GOAL_METRICS; m++) {
865 		if (sysfs_streq(buf, damos_sysfs_quota_goal_metric_strs[m])) {
866 			goal->metric = m;
867 			return count;
868 		}
869 	}
870 	return -EINVAL;
871 }
872 
873 static ssize_t target_value_show(struct kobject *kobj,
874 		struct kobj_attribute *attr, char *buf)
875 {
876 	struct damos_sysfs_quota_goal *goal = container_of(kobj, struct
877 			damos_sysfs_quota_goal, kobj);
878 
879 	return sysfs_emit(buf, "%lu\n", goal->target_value);
880 }
881 
882 static ssize_t target_value_store(struct kobject *kobj,
883 		struct kobj_attribute *attr, const char *buf, size_t count)
884 {
885 	struct damos_sysfs_quota_goal *goal = container_of(kobj, struct
886 			damos_sysfs_quota_goal, kobj);
887 	int err = kstrtoul(buf, 0, &goal->target_value);
888 
889 	return err ? err : count;
890 }
891 
892 static ssize_t current_value_show(struct kobject *kobj,
893 		struct kobj_attribute *attr, char *buf)
894 {
895 	struct damos_sysfs_quota_goal *goal = container_of(kobj, struct
896 			damos_sysfs_quota_goal, kobj);
897 
898 	return sysfs_emit(buf, "%lu\n", goal->current_value);
899 }
900 
901 static ssize_t current_value_store(struct kobject *kobj,
902 		struct kobj_attribute *attr, const char *buf, size_t count)
903 {
904 	struct damos_sysfs_quota_goal *goal = container_of(kobj, struct
905 			damos_sysfs_quota_goal, kobj);
906 	int err = kstrtoul(buf, 0, &goal->current_value);
907 
908 	/* feed callback should check existence of this file and read value */
909 	return err ? err : count;
910 }
911 
912 static void damos_sysfs_quota_goal_release(struct kobject *kobj)
913 {
914 	/* or, notify this release to the feed callback */
915 	kfree(container_of(kobj, struct damos_sysfs_quota_goal, kobj));
916 }
917 
918 static struct kobj_attribute damos_sysfs_quota_goal_target_metric_attr =
919 		__ATTR_RW_MODE(target_metric, 0600);
920 
921 static struct kobj_attribute damos_sysfs_quota_goal_target_value_attr =
922 		__ATTR_RW_MODE(target_value, 0600);
923 
924 static struct kobj_attribute damos_sysfs_quota_goal_current_value_attr =
925 		__ATTR_RW_MODE(current_value, 0600);
926 
927 static struct attribute *damos_sysfs_quota_goal_attrs[] = {
928 	&damos_sysfs_quota_goal_target_metric_attr.attr,
929 	&damos_sysfs_quota_goal_target_value_attr.attr,
930 	&damos_sysfs_quota_goal_current_value_attr.attr,
931 	NULL,
932 };
933 ATTRIBUTE_GROUPS(damos_sysfs_quota_goal);
934 
935 static const struct kobj_type damos_sysfs_quota_goal_ktype = {
936 	.release = damos_sysfs_quota_goal_release,
937 	.sysfs_ops = &kobj_sysfs_ops,
938 	.default_groups = damos_sysfs_quota_goal_groups,
939 };
940 
941 /*
942  * quota goals directory
943  */
944 
945 struct damos_sysfs_quota_goals {
946 	struct kobject kobj;
947 	struct damos_sysfs_quota_goal **goals_arr;	/* counted by nr */
948 	int nr;
949 };
950 
951 static struct damos_sysfs_quota_goals *damos_sysfs_quota_goals_alloc(void)
952 {
953 	return kzalloc(sizeof(struct damos_sysfs_quota_goals), GFP_KERNEL);
954 }
955 
956 static void damos_sysfs_quota_goals_rm_dirs(
957 		struct damos_sysfs_quota_goals *goals)
958 {
959 	struct damos_sysfs_quota_goal **goals_arr = goals->goals_arr;
960 	int i;
961 
962 	for (i = 0; i < goals->nr; i++)
963 		kobject_put(&goals_arr[i]->kobj);
964 	goals->nr = 0;
965 	kfree(goals_arr);
966 	goals->goals_arr = NULL;
967 }
968 
969 static int damos_sysfs_quota_goals_add_dirs(
970 		struct damos_sysfs_quota_goals *goals, int nr_goals)
971 {
972 	struct damos_sysfs_quota_goal **goals_arr, *goal;
973 	int err, i;
974 
975 	damos_sysfs_quota_goals_rm_dirs(goals);
976 	if (!nr_goals)
977 		return 0;
978 
979 	goals_arr = kmalloc_array(nr_goals, sizeof(*goals_arr),
980 			GFP_KERNEL | __GFP_NOWARN);
981 	if (!goals_arr)
982 		return -ENOMEM;
983 	goals->goals_arr = goals_arr;
984 
985 	for (i = 0; i < nr_goals; i++) {
986 		goal = damos_sysfs_quota_goal_alloc();
987 		if (!goal) {
988 			damos_sysfs_quota_goals_rm_dirs(goals);
989 			return -ENOMEM;
990 		}
991 
992 		err = kobject_init_and_add(&goal->kobj,
993 				&damos_sysfs_quota_goal_ktype, &goals->kobj,
994 				"%d", i);
995 		if (err) {
996 			kobject_put(&goal->kobj);
997 			damos_sysfs_quota_goals_rm_dirs(goals);
998 			return err;
999 		}
1000 
1001 		goals_arr[i] = goal;
1002 		goals->nr++;
1003 	}
1004 	return 0;
1005 }
1006 
1007 static ssize_t nr_goals_show(struct kobject *kobj,
1008 		struct kobj_attribute *attr, char *buf)
1009 {
1010 	struct damos_sysfs_quota_goals *goals = container_of(kobj,
1011 			struct damos_sysfs_quota_goals, kobj);
1012 
1013 	return sysfs_emit(buf, "%d\n", goals->nr);
1014 }
1015 
1016 static ssize_t nr_goals_store(struct kobject *kobj,
1017 		struct kobj_attribute *attr, const char *buf, size_t count)
1018 {
1019 	struct damos_sysfs_quota_goals *goals;
1020 	int nr, err = kstrtoint(buf, 0, &nr);
1021 
1022 	if (err)
1023 		return err;
1024 	if (nr < 0)
1025 		return -EINVAL;
1026 
1027 	goals = container_of(kobj, struct damos_sysfs_quota_goals, kobj);
1028 
1029 	if (!mutex_trylock(&damon_sysfs_lock))
1030 		return -EBUSY;
1031 	err = damos_sysfs_quota_goals_add_dirs(goals, nr);
1032 	mutex_unlock(&damon_sysfs_lock);
1033 	if (err)
1034 		return err;
1035 
1036 	return count;
1037 }
1038 
1039 static void damos_sysfs_quota_goals_release(struct kobject *kobj)
1040 {
1041 	kfree(container_of(kobj, struct damos_sysfs_quota_goals, kobj));
1042 }
1043 
1044 static struct kobj_attribute damos_sysfs_quota_goals_nr_attr =
1045 		__ATTR_RW_MODE(nr_goals, 0600);
1046 
1047 static struct attribute *damos_sysfs_quota_goals_attrs[] = {
1048 	&damos_sysfs_quota_goals_nr_attr.attr,
1049 	NULL,
1050 };
1051 ATTRIBUTE_GROUPS(damos_sysfs_quota_goals);
1052 
1053 static const struct kobj_type damos_sysfs_quota_goals_ktype = {
1054 	.release = damos_sysfs_quota_goals_release,
1055 	.sysfs_ops = &kobj_sysfs_ops,
1056 	.default_groups = damos_sysfs_quota_goals_groups,
1057 };
1058 
1059 /*
1060  * scheme/weights directory
1061  */
1062 
1063 struct damon_sysfs_weights {
1064 	struct kobject kobj;
1065 	unsigned int sz;
1066 	unsigned int nr_accesses;
1067 	unsigned int age;
1068 };
1069 
1070 static struct damon_sysfs_weights *damon_sysfs_weights_alloc(unsigned int sz,
1071 		unsigned int nr_accesses, unsigned int age)
1072 {
1073 	struct damon_sysfs_weights *weights = kmalloc(sizeof(*weights),
1074 			GFP_KERNEL);
1075 
1076 	if (!weights)
1077 		return NULL;
1078 	weights->kobj = (struct kobject){};
1079 	weights->sz = sz;
1080 	weights->nr_accesses = nr_accesses;
1081 	weights->age = age;
1082 	return weights;
1083 }
1084 
1085 static ssize_t sz_permil_show(struct kobject *kobj,
1086 		struct kobj_attribute *attr, char *buf)
1087 {
1088 	struct damon_sysfs_weights *weights = container_of(kobj,
1089 			struct damon_sysfs_weights, kobj);
1090 
1091 	return sysfs_emit(buf, "%u\n", weights->sz);
1092 }
1093 
1094 static ssize_t sz_permil_store(struct kobject *kobj,
1095 		struct kobj_attribute *attr, const char *buf, size_t count)
1096 {
1097 	struct damon_sysfs_weights *weights = container_of(kobj,
1098 			struct damon_sysfs_weights, kobj);
1099 	int err = kstrtouint(buf, 0, &weights->sz);
1100 
1101 	return err ? err : count;
1102 }
1103 
1104 static ssize_t nr_accesses_permil_show(struct kobject *kobj,
1105 		struct kobj_attribute *attr, char *buf)
1106 {
1107 	struct damon_sysfs_weights *weights = container_of(kobj,
1108 			struct damon_sysfs_weights, kobj);
1109 
1110 	return sysfs_emit(buf, "%u\n", weights->nr_accesses);
1111 }
1112 
1113 static ssize_t nr_accesses_permil_store(struct kobject *kobj,
1114 		struct kobj_attribute *attr, const char *buf, size_t count)
1115 {
1116 	struct damon_sysfs_weights *weights = container_of(kobj,
1117 			struct damon_sysfs_weights, kobj);
1118 	int err = kstrtouint(buf, 0, &weights->nr_accesses);
1119 
1120 	return err ? err : count;
1121 }
1122 
1123 static ssize_t age_permil_show(struct kobject *kobj,
1124 		struct kobj_attribute *attr, char *buf)
1125 {
1126 	struct damon_sysfs_weights *weights = container_of(kobj,
1127 			struct damon_sysfs_weights, kobj);
1128 
1129 	return sysfs_emit(buf, "%u\n", weights->age);
1130 }
1131 
1132 static ssize_t age_permil_store(struct kobject *kobj,
1133 		struct kobj_attribute *attr, const char *buf, size_t count)
1134 {
1135 	struct damon_sysfs_weights *weights = container_of(kobj,
1136 			struct damon_sysfs_weights, kobj);
1137 	int err = kstrtouint(buf, 0, &weights->age);
1138 
1139 	return err ? err : count;
1140 }
1141 
1142 static void damon_sysfs_weights_release(struct kobject *kobj)
1143 {
1144 	kfree(container_of(kobj, struct damon_sysfs_weights, kobj));
1145 }
1146 
1147 static struct kobj_attribute damon_sysfs_weights_sz_attr =
1148 		__ATTR_RW_MODE(sz_permil, 0600);
1149 
1150 static struct kobj_attribute damon_sysfs_weights_nr_accesses_attr =
1151 		__ATTR_RW_MODE(nr_accesses_permil, 0600);
1152 
1153 static struct kobj_attribute damon_sysfs_weights_age_attr =
1154 		__ATTR_RW_MODE(age_permil, 0600);
1155 
1156 static struct attribute *damon_sysfs_weights_attrs[] = {
1157 	&damon_sysfs_weights_sz_attr.attr,
1158 	&damon_sysfs_weights_nr_accesses_attr.attr,
1159 	&damon_sysfs_weights_age_attr.attr,
1160 	NULL,
1161 };
1162 ATTRIBUTE_GROUPS(damon_sysfs_weights);
1163 
1164 static const struct kobj_type damon_sysfs_weights_ktype = {
1165 	.release = damon_sysfs_weights_release,
1166 	.sysfs_ops = &kobj_sysfs_ops,
1167 	.default_groups = damon_sysfs_weights_groups,
1168 };
1169 
1170 /*
1171  * quotas directory
1172  */
1173 
1174 struct damon_sysfs_quotas {
1175 	struct kobject kobj;
1176 	struct damon_sysfs_weights *weights;
1177 	struct damos_sysfs_quota_goals *goals;
1178 	unsigned long ms;
1179 	unsigned long sz;
1180 	unsigned long reset_interval_ms;
1181 	unsigned long effective_sz;	/* Effective size quota in bytes */
1182 };
1183 
1184 static struct damon_sysfs_quotas *damon_sysfs_quotas_alloc(void)
1185 {
1186 	return kzalloc(sizeof(struct damon_sysfs_quotas), GFP_KERNEL);
1187 }
1188 
1189 static int damon_sysfs_quotas_add_dirs(struct damon_sysfs_quotas *quotas)
1190 {
1191 	struct damon_sysfs_weights *weights;
1192 	struct damos_sysfs_quota_goals *goals;
1193 	int err;
1194 
1195 	weights = damon_sysfs_weights_alloc(0, 0, 0);
1196 	if (!weights)
1197 		return -ENOMEM;
1198 
1199 	err = kobject_init_and_add(&weights->kobj, &damon_sysfs_weights_ktype,
1200 			&quotas->kobj, "weights");
1201 	if (err) {
1202 		kobject_put(&weights->kobj);
1203 		return err;
1204 	}
1205 	quotas->weights = weights;
1206 
1207 	goals = damos_sysfs_quota_goals_alloc();
1208 	if (!goals) {
1209 		kobject_put(&weights->kobj);
1210 		return -ENOMEM;
1211 	}
1212 	err = kobject_init_and_add(&goals->kobj,
1213 			&damos_sysfs_quota_goals_ktype, &quotas->kobj,
1214 			"goals");
1215 	if (err) {
1216 		kobject_put(&weights->kobj);
1217 		kobject_put(&goals->kobj);
1218 	} else {
1219 		quotas->goals = goals;
1220 	}
1221 
1222 	return err;
1223 }
1224 
1225 static void damon_sysfs_quotas_rm_dirs(struct damon_sysfs_quotas *quotas)
1226 {
1227 	kobject_put(&quotas->weights->kobj);
1228 	damos_sysfs_quota_goals_rm_dirs(quotas->goals);
1229 	kobject_put(&quotas->goals->kobj);
1230 }
1231 
1232 static ssize_t ms_show(struct kobject *kobj, struct kobj_attribute *attr,
1233 		char *buf)
1234 {
1235 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1236 			struct damon_sysfs_quotas, kobj);
1237 
1238 	return sysfs_emit(buf, "%lu\n", quotas->ms);
1239 }
1240 
1241 static ssize_t ms_store(struct kobject *kobj, struct kobj_attribute *attr,
1242 		const char *buf, size_t count)
1243 {
1244 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1245 			struct damon_sysfs_quotas, kobj);
1246 	int err = kstrtoul(buf, 0, &quotas->ms);
1247 
1248 	if (err)
1249 		return -EINVAL;
1250 	return count;
1251 }
1252 
1253 static ssize_t bytes_show(struct kobject *kobj, struct kobj_attribute *attr,
1254 		char *buf)
1255 {
1256 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1257 			struct damon_sysfs_quotas, kobj);
1258 
1259 	return sysfs_emit(buf, "%lu\n", quotas->sz);
1260 }
1261 
1262 static ssize_t bytes_store(struct kobject *kobj,
1263 		struct kobj_attribute *attr, const char *buf, size_t count)
1264 {
1265 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1266 			struct damon_sysfs_quotas, kobj);
1267 	int err = kstrtoul(buf, 0, &quotas->sz);
1268 
1269 	if (err)
1270 		return -EINVAL;
1271 	return count;
1272 }
1273 
1274 static ssize_t reset_interval_ms_show(struct kobject *kobj,
1275 		struct kobj_attribute *attr, char *buf)
1276 {
1277 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1278 			struct damon_sysfs_quotas, kobj);
1279 
1280 	return sysfs_emit(buf, "%lu\n", quotas->reset_interval_ms);
1281 }
1282 
1283 static ssize_t reset_interval_ms_store(struct kobject *kobj,
1284 		struct kobj_attribute *attr, const char *buf, size_t count)
1285 {
1286 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1287 			struct damon_sysfs_quotas, kobj);
1288 	int err = kstrtoul(buf, 0, &quotas->reset_interval_ms);
1289 
1290 	if (err)
1291 		return -EINVAL;
1292 	return count;
1293 }
1294 
1295 static ssize_t effective_bytes_show(struct kobject *kobj,
1296 		struct kobj_attribute *attr, char *buf)
1297 {
1298 	struct damon_sysfs_quotas *quotas = container_of(kobj,
1299 			struct damon_sysfs_quotas, kobj);
1300 
1301 	return sysfs_emit(buf, "%lu\n", quotas->effective_sz);
1302 }
1303 
1304 static void damon_sysfs_quotas_release(struct kobject *kobj)
1305 {
1306 	kfree(container_of(kobj, struct damon_sysfs_quotas, kobj));
1307 }
1308 
1309 static struct kobj_attribute damon_sysfs_quotas_ms_attr =
1310 		__ATTR_RW_MODE(ms, 0600);
1311 
1312 static struct kobj_attribute damon_sysfs_quotas_sz_attr =
1313 		__ATTR_RW_MODE(bytes, 0600);
1314 
1315 static struct kobj_attribute damon_sysfs_quotas_reset_interval_ms_attr =
1316 		__ATTR_RW_MODE(reset_interval_ms, 0600);
1317 
1318 static struct kobj_attribute damon_sysfs_quotas_effective_bytes_attr =
1319 		__ATTR_RO_MODE(effective_bytes, 0400);
1320 
1321 static struct attribute *damon_sysfs_quotas_attrs[] = {
1322 	&damon_sysfs_quotas_ms_attr.attr,
1323 	&damon_sysfs_quotas_sz_attr.attr,
1324 	&damon_sysfs_quotas_reset_interval_ms_attr.attr,
1325 	&damon_sysfs_quotas_effective_bytes_attr.attr,
1326 	NULL,
1327 };
1328 ATTRIBUTE_GROUPS(damon_sysfs_quotas);
1329 
1330 static const struct kobj_type damon_sysfs_quotas_ktype = {
1331 	.release = damon_sysfs_quotas_release,
1332 	.sysfs_ops = &kobj_sysfs_ops,
1333 	.default_groups = damon_sysfs_quotas_groups,
1334 };
1335 
1336 /*
1337  * access_pattern directory
1338  */
1339 
1340 struct damon_sysfs_access_pattern {
1341 	struct kobject kobj;
1342 	struct damon_sysfs_ul_range *sz;
1343 	struct damon_sysfs_ul_range *nr_accesses;
1344 	struct damon_sysfs_ul_range *age;
1345 };
1346 
1347 static
1348 struct damon_sysfs_access_pattern *damon_sysfs_access_pattern_alloc(void)
1349 {
1350 	struct damon_sysfs_access_pattern *access_pattern =
1351 		kmalloc(sizeof(*access_pattern), GFP_KERNEL);
1352 
1353 	if (!access_pattern)
1354 		return NULL;
1355 	access_pattern->kobj = (struct kobject){};
1356 	return access_pattern;
1357 }
1358 
1359 static int damon_sysfs_access_pattern_add_range_dir(
1360 		struct damon_sysfs_access_pattern *access_pattern,
1361 		struct damon_sysfs_ul_range **range_dir_ptr,
1362 		char *name)
1363 {
1364 	struct damon_sysfs_ul_range *range = damon_sysfs_ul_range_alloc(0, 0);
1365 	int err;
1366 
1367 	if (!range)
1368 		return -ENOMEM;
1369 	err = kobject_init_and_add(&range->kobj, &damon_sysfs_ul_range_ktype,
1370 			&access_pattern->kobj, name);
1371 	if (err)
1372 		kobject_put(&range->kobj);
1373 	else
1374 		*range_dir_ptr = range;
1375 	return err;
1376 }
1377 
1378 static int damon_sysfs_access_pattern_add_dirs(
1379 		struct damon_sysfs_access_pattern *access_pattern)
1380 {
1381 	int err;
1382 
1383 	err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
1384 			&access_pattern->sz, "sz");
1385 	if (err)
1386 		goto put_sz_out;
1387 
1388 	err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
1389 			&access_pattern->nr_accesses, "nr_accesses");
1390 	if (err)
1391 		goto put_nr_accesses_sz_out;
1392 
1393 	err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
1394 			&access_pattern->age, "age");
1395 	if (err)
1396 		goto put_age_nr_accesses_sz_out;
1397 	return 0;
1398 
1399 put_age_nr_accesses_sz_out:
1400 	kobject_put(&access_pattern->age->kobj);
1401 	access_pattern->age = NULL;
1402 put_nr_accesses_sz_out:
1403 	kobject_put(&access_pattern->nr_accesses->kobj);
1404 	access_pattern->nr_accesses = NULL;
1405 put_sz_out:
1406 	kobject_put(&access_pattern->sz->kobj);
1407 	access_pattern->sz = NULL;
1408 	return err;
1409 }
1410 
1411 static void damon_sysfs_access_pattern_rm_dirs(
1412 		struct damon_sysfs_access_pattern *access_pattern)
1413 {
1414 	kobject_put(&access_pattern->sz->kobj);
1415 	kobject_put(&access_pattern->nr_accesses->kobj);
1416 	kobject_put(&access_pattern->age->kobj);
1417 }
1418 
1419 static void damon_sysfs_access_pattern_release(struct kobject *kobj)
1420 {
1421 	kfree(container_of(kobj, struct damon_sysfs_access_pattern, kobj));
1422 }
1423 
1424 static struct attribute *damon_sysfs_access_pattern_attrs[] = {
1425 	NULL,
1426 };
1427 ATTRIBUTE_GROUPS(damon_sysfs_access_pattern);
1428 
1429 static const struct kobj_type damon_sysfs_access_pattern_ktype = {
1430 	.release = damon_sysfs_access_pattern_release,
1431 	.sysfs_ops = &kobj_sysfs_ops,
1432 	.default_groups = damon_sysfs_access_pattern_groups,
1433 };
1434 
1435 /*
1436  * scheme directory
1437  */
1438 
1439 struct damon_sysfs_scheme {
1440 	struct kobject kobj;
1441 	enum damos_action action;
1442 	struct damon_sysfs_access_pattern *access_pattern;
1443 	unsigned long apply_interval_us;
1444 	struct damon_sysfs_quotas *quotas;
1445 	struct damon_sysfs_watermarks *watermarks;
1446 	struct damon_sysfs_scheme_filters *filters;
1447 	struct damon_sysfs_stats *stats;
1448 	struct damon_sysfs_scheme_regions *tried_regions;
1449 	int target_nid;
1450 };
1451 
1452 /* This should match with enum damos_action */
1453 static const char * const damon_sysfs_damos_action_strs[] = {
1454 	"willneed",
1455 	"cold",
1456 	"pageout",
1457 	"hugepage",
1458 	"nohugepage",
1459 	"lru_prio",
1460 	"lru_deprio",
1461 	"migrate_hot",
1462 	"migrate_cold",
1463 	"stat",
1464 };
1465 
1466 static struct damon_sysfs_scheme *damon_sysfs_scheme_alloc(
1467 		enum damos_action action, unsigned long apply_interval_us)
1468 {
1469 	struct damon_sysfs_scheme *scheme = kmalloc(sizeof(*scheme),
1470 				GFP_KERNEL);
1471 
1472 	if (!scheme)
1473 		return NULL;
1474 	scheme->kobj = (struct kobject){};
1475 	scheme->action = action;
1476 	scheme->apply_interval_us = apply_interval_us;
1477 	scheme->target_nid = NUMA_NO_NODE;
1478 	return scheme;
1479 }
1480 
1481 static int damon_sysfs_scheme_set_access_pattern(
1482 		struct damon_sysfs_scheme *scheme)
1483 {
1484 	struct damon_sysfs_access_pattern *access_pattern;
1485 	int err;
1486 
1487 	access_pattern = damon_sysfs_access_pattern_alloc();
1488 	if (!access_pattern)
1489 		return -ENOMEM;
1490 	err = kobject_init_and_add(&access_pattern->kobj,
1491 			&damon_sysfs_access_pattern_ktype, &scheme->kobj,
1492 			"access_pattern");
1493 	if (err)
1494 		goto out;
1495 	err = damon_sysfs_access_pattern_add_dirs(access_pattern);
1496 	if (err)
1497 		goto out;
1498 	scheme->access_pattern = access_pattern;
1499 	return 0;
1500 
1501 out:
1502 	kobject_put(&access_pattern->kobj);
1503 	return err;
1504 }
1505 
1506 static int damon_sysfs_scheme_set_quotas(struct damon_sysfs_scheme *scheme)
1507 {
1508 	struct damon_sysfs_quotas *quotas = damon_sysfs_quotas_alloc();
1509 	int err;
1510 
1511 	if (!quotas)
1512 		return -ENOMEM;
1513 	err = kobject_init_and_add(&quotas->kobj, &damon_sysfs_quotas_ktype,
1514 			&scheme->kobj, "quotas");
1515 	if (err)
1516 		goto out;
1517 	err = damon_sysfs_quotas_add_dirs(quotas);
1518 	if (err)
1519 		goto out;
1520 	scheme->quotas = quotas;
1521 	return 0;
1522 
1523 out:
1524 	kobject_put(&quotas->kobj);
1525 	return err;
1526 }
1527 
1528 static int damon_sysfs_scheme_set_watermarks(struct damon_sysfs_scheme *scheme)
1529 {
1530 	struct damon_sysfs_watermarks *watermarks =
1531 		damon_sysfs_watermarks_alloc(DAMOS_WMARK_NONE, 0, 0, 0, 0);
1532 	int err;
1533 
1534 	if (!watermarks)
1535 		return -ENOMEM;
1536 	err = kobject_init_and_add(&watermarks->kobj,
1537 			&damon_sysfs_watermarks_ktype, &scheme->kobj,
1538 			"watermarks");
1539 	if (err)
1540 		kobject_put(&watermarks->kobj);
1541 	else
1542 		scheme->watermarks = watermarks;
1543 	return err;
1544 }
1545 
1546 static int damon_sysfs_scheme_set_filters(struct damon_sysfs_scheme *scheme)
1547 {
1548 	struct damon_sysfs_scheme_filters *filters =
1549 		damon_sysfs_scheme_filters_alloc();
1550 	int err;
1551 
1552 	if (!filters)
1553 		return -ENOMEM;
1554 	err = kobject_init_and_add(&filters->kobj,
1555 			&damon_sysfs_scheme_filters_ktype, &scheme->kobj,
1556 			"filters");
1557 	if (err)
1558 		kobject_put(&filters->kobj);
1559 	else
1560 		scheme->filters = filters;
1561 	return err;
1562 }
1563 
1564 static int damon_sysfs_scheme_set_stats(struct damon_sysfs_scheme *scheme)
1565 {
1566 	struct damon_sysfs_stats *stats = damon_sysfs_stats_alloc();
1567 	int err;
1568 
1569 	if (!stats)
1570 		return -ENOMEM;
1571 	err = kobject_init_and_add(&stats->kobj, &damon_sysfs_stats_ktype,
1572 			&scheme->kobj, "stats");
1573 	if (err)
1574 		kobject_put(&stats->kobj);
1575 	else
1576 		scheme->stats = stats;
1577 	return err;
1578 }
1579 
1580 static int damon_sysfs_scheme_set_tried_regions(
1581 		struct damon_sysfs_scheme *scheme)
1582 {
1583 	struct damon_sysfs_scheme_regions *tried_regions =
1584 		damon_sysfs_scheme_regions_alloc();
1585 	int err;
1586 
1587 	if (!tried_regions)
1588 		return -ENOMEM;
1589 	err = kobject_init_and_add(&tried_regions->kobj,
1590 			&damon_sysfs_scheme_regions_ktype, &scheme->kobj,
1591 			"tried_regions");
1592 	if (err)
1593 		kobject_put(&tried_regions->kobj);
1594 	else
1595 		scheme->tried_regions = tried_regions;
1596 	return err;
1597 }
1598 
1599 static int damon_sysfs_scheme_add_dirs(struct damon_sysfs_scheme *scheme)
1600 {
1601 	int err;
1602 
1603 	err = damon_sysfs_scheme_set_access_pattern(scheme);
1604 	if (err)
1605 		return err;
1606 	err = damon_sysfs_scheme_set_quotas(scheme);
1607 	if (err)
1608 		goto put_access_pattern_out;
1609 	err = damon_sysfs_scheme_set_watermarks(scheme);
1610 	if (err)
1611 		goto put_quotas_access_pattern_out;
1612 	err = damon_sysfs_scheme_set_filters(scheme);
1613 	if (err)
1614 		goto put_watermarks_quotas_access_pattern_out;
1615 	err = damon_sysfs_scheme_set_stats(scheme);
1616 	if (err)
1617 		goto put_filters_watermarks_quotas_access_pattern_out;
1618 	err = damon_sysfs_scheme_set_tried_regions(scheme);
1619 	if (err)
1620 		goto put_tried_regions_out;
1621 	return 0;
1622 
1623 put_tried_regions_out:
1624 	kobject_put(&scheme->tried_regions->kobj);
1625 	scheme->tried_regions = NULL;
1626 put_filters_watermarks_quotas_access_pattern_out:
1627 	kobject_put(&scheme->filters->kobj);
1628 	scheme->filters = NULL;
1629 put_watermarks_quotas_access_pattern_out:
1630 	kobject_put(&scheme->watermarks->kobj);
1631 	scheme->watermarks = NULL;
1632 put_quotas_access_pattern_out:
1633 	kobject_put(&scheme->quotas->kobj);
1634 	scheme->quotas = NULL;
1635 put_access_pattern_out:
1636 	kobject_put(&scheme->access_pattern->kobj);
1637 	scheme->access_pattern = NULL;
1638 	return err;
1639 }
1640 
1641 static void damon_sysfs_scheme_rm_dirs(struct damon_sysfs_scheme *scheme)
1642 {
1643 	damon_sysfs_access_pattern_rm_dirs(scheme->access_pattern);
1644 	kobject_put(&scheme->access_pattern->kobj);
1645 	damon_sysfs_quotas_rm_dirs(scheme->quotas);
1646 	kobject_put(&scheme->quotas->kobj);
1647 	kobject_put(&scheme->watermarks->kobj);
1648 	damon_sysfs_scheme_filters_rm_dirs(scheme->filters);
1649 	kobject_put(&scheme->filters->kobj);
1650 	kobject_put(&scheme->stats->kobj);
1651 	damon_sysfs_scheme_regions_rm_dirs(scheme->tried_regions);
1652 	kobject_put(&scheme->tried_regions->kobj);
1653 }
1654 
1655 static ssize_t action_show(struct kobject *kobj, struct kobj_attribute *attr,
1656 		char *buf)
1657 {
1658 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1659 			struct damon_sysfs_scheme, kobj);
1660 
1661 	return sysfs_emit(buf, "%s\n",
1662 			damon_sysfs_damos_action_strs[scheme->action]);
1663 }
1664 
1665 static ssize_t action_store(struct kobject *kobj, struct kobj_attribute *attr,
1666 		const char *buf, size_t count)
1667 {
1668 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1669 			struct damon_sysfs_scheme, kobj);
1670 	enum damos_action action;
1671 
1672 	for (action = 0; action < NR_DAMOS_ACTIONS; action++) {
1673 		if (sysfs_streq(buf, damon_sysfs_damos_action_strs[action])) {
1674 			scheme->action = action;
1675 			return count;
1676 		}
1677 	}
1678 	return -EINVAL;
1679 }
1680 
1681 static ssize_t apply_interval_us_show(struct kobject *kobj,
1682 		struct kobj_attribute *attr, char *buf)
1683 {
1684 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1685 			struct damon_sysfs_scheme, kobj);
1686 
1687 	return sysfs_emit(buf, "%lu\n", scheme->apply_interval_us);
1688 }
1689 
1690 static ssize_t apply_interval_us_store(struct kobject *kobj,
1691 		struct kobj_attribute *attr, const char *buf, size_t count)
1692 {
1693 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1694 			struct damon_sysfs_scheme, kobj);
1695 	int err = kstrtoul(buf, 0, &scheme->apply_interval_us);
1696 
1697 	return err ? err : count;
1698 }
1699 
1700 static ssize_t target_nid_show(struct kobject *kobj,
1701 		struct kobj_attribute *attr, char *buf)
1702 {
1703 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1704 			struct damon_sysfs_scheme, kobj);
1705 
1706 	return sysfs_emit(buf, "%d\n", scheme->target_nid);
1707 }
1708 
1709 static ssize_t target_nid_store(struct kobject *kobj,
1710 		struct kobj_attribute *attr, const char *buf, size_t count)
1711 {
1712 	struct damon_sysfs_scheme *scheme = container_of(kobj,
1713 			struct damon_sysfs_scheme, kobj);
1714 	int err = 0;
1715 
1716 	/* TODO: error handling for target_nid range. */
1717 	err = kstrtoint(buf, 0, &scheme->target_nid);
1718 
1719 	return err ? err : count;
1720 }
1721 
1722 static void damon_sysfs_scheme_release(struct kobject *kobj)
1723 {
1724 	kfree(container_of(kobj, struct damon_sysfs_scheme, kobj));
1725 }
1726 
1727 static struct kobj_attribute damon_sysfs_scheme_action_attr =
1728 		__ATTR_RW_MODE(action, 0600);
1729 
1730 static struct kobj_attribute damon_sysfs_scheme_apply_interval_us_attr =
1731 		__ATTR_RW_MODE(apply_interval_us, 0600);
1732 
1733 static struct kobj_attribute damon_sysfs_scheme_target_nid_attr =
1734 		__ATTR_RW_MODE(target_nid, 0600);
1735 
1736 static struct attribute *damon_sysfs_scheme_attrs[] = {
1737 	&damon_sysfs_scheme_action_attr.attr,
1738 	&damon_sysfs_scheme_apply_interval_us_attr.attr,
1739 	&damon_sysfs_scheme_target_nid_attr.attr,
1740 	NULL,
1741 };
1742 ATTRIBUTE_GROUPS(damon_sysfs_scheme);
1743 
1744 static const struct kobj_type damon_sysfs_scheme_ktype = {
1745 	.release = damon_sysfs_scheme_release,
1746 	.sysfs_ops = &kobj_sysfs_ops,
1747 	.default_groups = damon_sysfs_scheme_groups,
1748 };
1749 
1750 /*
1751  * schemes directory
1752  */
1753 
1754 struct damon_sysfs_schemes *damon_sysfs_schemes_alloc(void)
1755 {
1756 	return kzalloc(sizeof(struct damon_sysfs_schemes), GFP_KERNEL);
1757 }
1758 
1759 void damon_sysfs_schemes_rm_dirs(struct damon_sysfs_schemes *schemes)
1760 {
1761 	struct damon_sysfs_scheme **schemes_arr = schemes->schemes_arr;
1762 	int i;
1763 
1764 	for (i = 0; i < schemes->nr; i++) {
1765 		damon_sysfs_scheme_rm_dirs(schemes_arr[i]);
1766 		kobject_put(&schemes_arr[i]->kobj);
1767 	}
1768 	schemes->nr = 0;
1769 	kfree(schemes_arr);
1770 	schemes->schemes_arr = NULL;
1771 }
1772 
1773 static int damon_sysfs_schemes_add_dirs(struct damon_sysfs_schemes *schemes,
1774 		int nr_schemes)
1775 {
1776 	struct damon_sysfs_scheme **schemes_arr, *scheme;
1777 	int err, i;
1778 
1779 	damon_sysfs_schemes_rm_dirs(schemes);
1780 	if (!nr_schemes)
1781 		return 0;
1782 
1783 	schemes_arr = kmalloc_array(nr_schemes, sizeof(*schemes_arr),
1784 			GFP_KERNEL | __GFP_NOWARN);
1785 	if (!schemes_arr)
1786 		return -ENOMEM;
1787 	schemes->schemes_arr = schemes_arr;
1788 
1789 	for (i = 0; i < nr_schemes; i++) {
1790 		/*
1791 		 * apply_interval_us as 0 means same to aggregation interval
1792 		 * (same to before-apply_interval behavior)
1793 		 */
1794 		scheme = damon_sysfs_scheme_alloc(DAMOS_STAT, 0);
1795 		if (!scheme) {
1796 			damon_sysfs_schemes_rm_dirs(schemes);
1797 			return -ENOMEM;
1798 		}
1799 
1800 		err = kobject_init_and_add(&scheme->kobj,
1801 				&damon_sysfs_scheme_ktype, &schemes->kobj,
1802 				"%d", i);
1803 		if (err)
1804 			goto out;
1805 		err = damon_sysfs_scheme_add_dirs(scheme);
1806 		if (err)
1807 			goto out;
1808 
1809 		schemes_arr[i] = scheme;
1810 		schemes->nr++;
1811 	}
1812 	return 0;
1813 
1814 out:
1815 	damon_sysfs_schemes_rm_dirs(schemes);
1816 	kobject_put(&scheme->kobj);
1817 	return err;
1818 }
1819 
1820 static ssize_t nr_schemes_show(struct kobject *kobj,
1821 		struct kobj_attribute *attr, char *buf)
1822 {
1823 	struct damon_sysfs_schemes *schemes = container_of(kobj,
1824 			struct damon_sysfs_schemes, kobj);
1825 
1826 	return sysfs_emit(buf, "%d\n", schemes->nr);
1827 }
1828 
1829 static ssize_t nr_schemes_store(struct kobject *kobj,
1830 		struct kobj_attribute *attr, const char *buf, size_t count)
1831 {
1832 	struct damon_sysfs_schemes *schemes;
1833 	int nr, err = kstrtoint(buf, 0, &nr);
1834 
1835 	if (err)
1836 		return err;
1837 	if (nr < 0)
1838 		return -EINVAL;
1839 
1840 	schemes = container_of(kobj, struct damon_sysfs_schemes, kobj);
1841 
1842 	if (!mutex_trylock(&damon_sysfs_lock))
1843 		return -EBUSY;
1844 	err = damon_sysfs_schemes_add_dirs(schemes, nr);
1845 	mutex_unlock(&damon_sysfs_lock);
1846 	if (err)
1847 		return err;
1848 	return count;
1849 }
1850 
1851 static void damon_sysfs_schemes_release(struct kobject *kobj)
1852 {
1853 	kfree(container_of(kobj, struct damon_sysfs_schemes, kobj));
1854 }
1855 
1856 static struct kobj_attribute damon_sysfs_schemes_nr_attr =
1857 		__ATTR_RW_MODE(nr_schemes, 0600);
1858 
1859 static struct attribute *damon_sysfs_schemes_attrs[] = {
1860 	&damon_sysfs_schemes_nr_attr.attr,
1861 	NULL,
1862 };
1863 ATTRIBUTE_GROUPS(damon_sysfs_schemes);
1864 
1865 const struct kobj_type damon_sysfs_schemes_ktype = {
1866 	.release = damon_sysfs_schemes_release,
1867 	.sysfs_ops = &kobj_sysfs_ops,
1868 	.default_groups = damon_sysfs_schemes_groups,
1869 };
1870 
1871 static bool damon_sysfs_memcg_path_eq(struct mem_cgroup *memcg,
1872 		char *memcg_path_buf, char *path)
1873 {
1874 #ifdef CONFIG_MEMCG
1875 	cgroup_path(memcg->css.cgroup, memcg_path_buf, PATH_MAX);
1876 	if (sysfs_streq(memcg_path_buf, path))
1877 		return true;
1878 #endif /* CONFIG_MEMCG */
1879 	return false;
1880 }
1881 
1882 static int damon_sysfs_memcg_path_to_id(char *memcg_path, unsigned short *id)
1883 {
1884 	struct mem_cgroup *memcg;
1885 	char *path;
1886 	bool found = false;
1887 
1888 	if (!memcg_path)
1889 		return -EINVAL;
1890 
1891 	path = kmalloc(sizeof(*path) * PATH_MAX, GFP_KERNEL);
1892 	if (!path)
1893 		return -ENOMEM;
1894 
1895 	for (memcg = mem_cgroup_iter(NULL, NULL, NULL); memcg;
1896 			memcg = mem_cgroup_iter(NULL, memcg, NULL)) {
1897 		/* skip removed memcg */
1898 		if (!mem_cgroup_id(memcg))
1899 			continue;
1900 		if (damon_sysfs_memcg_path_eq(memcg, path, memcg_path)) {
1901 			*id = mem_cgroup_id(memcg);
1902 			found = true;
1903 			break;
1904 		}
1905 	}
1906 
1907 	kfree(path);
1908 	return found ? 0 : -EINVAL;
1909 }
1910 
1911 static int damon_sysfs_add_scheme_filters(struct damos *scheme,
1912 		struct damon_sysfs_scheme_filters *sysfs_filters)
1913 {
1914 	int i;
1915 
1916 	for (i = 0; i < sysfs_filters->nr; i++) {
1917 		struct damon_sysfs_scheme_filter *sysfs_filter =
1918 			sysfs_filters->filters_arr[i];
1919 		struct damos_filter *filter =
1920 			damos_new_filter(sysfs_filter->type,
1921 					sysfs_filter->matching);
1922 		int err;
1923 
1924 		if (!filter)
1925 			return -ENOMEM;
1926 		if (filter->type == DAMOS_FILTER_TYPE_MEMCG) {
1927 			err = damon_sysfs_memcg_path_to_id(
1928 					sysfs_filter->memcg_path,
1929 					&filter->memcg_id);
1930 			if (err) {
1931 				damos_destroy_filter(filter);
1932 				return err;
1933 			}
1934 		} else if (filter->type == DAMOS_FILTER_TYPE_ADDR) {
1935 			if (sysfs_filter->addr_range.end <
1936 					sysfs_filter->addr_range.start) {
1937 				damos_destroy_filter(filter);
1938 				return -EINVAL;
1939 			}
1940 			filter->addr_range = sysfs_filter->addr_range;
1941 		} else if (filter->type == DAMOS_FILTER_TYPE_TARGET) {
1942 			filter->target_idx = sysfs_filter->target_idx;
1943 		}
1944 
1945 		damos_add_filter(scheme, filter);
1946 	}
1947 	return 0;
1948 }
1949 
1950 static int damos_sysfs_add_quota_score(
1951 		struct damos_sysfs_quota_goals *sysfs_goals,
1952 		struct damos_quota *quota)
1953 {
1954 	struct damos_quota_goal *goal;
1955 	int i;
1956 
1957 	for (i = 0; i < sysfs_goals->nr; i++) {
1958 		struct damos_sysfs_quota_goal *sysfs_goal =
1959 			sysfs_goals->goals_arr[i];
1960 
1961 		if (!sysfs_goal->target_value)
1962 			continue;
1963 
1964 		goal = damos_new_quota_goal(sysfs_goal->metric,
1965 				sysfs_goal->target_value);
1966 		if (!goal)
1967 			return -ENOMEM;
1968 		if (sysfs_goal->metric == DAMOS_QUOTA_USER_INPUT)
1969 			goal->current_value = sysfs_goal->current_value;
1970 		damos_add_quota_goal(quota, goal);
1971 	}
1972 	return 0;
1973 }
1974 
1975 int damos_sysfs_set_quota_scores(struct damon_sysfs_schemes *sysfs_schemes,
1976 		struct damon_ctx *ctx)
1977 {
1978 	struct damos *scheme;
1979 	struct damos_quota quota = {};
1980 	int i = 0;
1981 
1982 	INIT_LIST_HEAD(&quota.goals);
1983 	damon_for_each_scheme(scheme, ctx) {
1984 		struct damon_sysfs_scheme *sysfs_scheme;
1985 		struct damos_quota_goal *g, *g_next;
1986 		int err;
1987 
1988 		/* user could have removed the scheme sysfs dir */
1989 		if (i >= sysfs_schemes->nr)
1990 			break;
1991 
1992 		sysfs_scheme = sysfs_schemes->schemes_arr[i];
1993 		err = damos_sysfs_add_quota_score(sysfs_scheme->quotas->goals,
1994 				&quota);
1995 		if (err) {
1996 			damos_for_each_quota_goal_safe(g, g_next, &quota)
1997 				damos_destroy_quota_goal(g);
1998 			return err;
1999 		}
2000 		err = damos_commit_quota_goals(&scheme->quota, &quota);
2001 		damos_for_each_quota_goal_safe(g, g_next, &quota)
2002 			damos_destroy_quota_goal(g);
2003 		if (err)
2004 			return err;
2005 		i++;
2006 	}
2007 	return 0;
2008 }
2009 
2010 void damos_sysfs_update_effective_quotas(
2011 		struct damon_sysfs_schemes *sysfs_schemes,
2012 		struct damon_ctx *ctx)
2013 {
2014 	struct damos *scheme;
2015 	int schemes_idx = 0;
2016 
2017 	damon_for_each_scheme(scheme, ctx) {
2018 		struct damon_sysfs_quotas *sysfs_quotas;
2019 
2020 		/* user could have removed the scheme sysfs dir */
2021 		if (schemes_idx >= sysfs_schemes->nr)
2022 			break;
2023 
2024 		sysfs_quotas =
2025 			sysfs_schemes->schemes_arr[schemes_idx++]->quotas;
2026 		sysfs_quotas->effective_sz = scheme->quota.esz;
2027 	}
2028 }
2029 
2030 static struct damos *damon_sysfs_mk_scheme(
2031 		struct damon_sysfs_scheme *sysfs_scheme)
2032 {
2033 	struct damon_sysfs_access_pattern *access_pattern =
2034 		sysfs_scheme->access_pattern;
2035 	struct damon_sysfs_quotas *sysfs_quotas = sysfs_scheme->quotas;
2036 	struct damon_sysfs_weights *sysfs_weights = sysfs_quotas->weights;
2037 	struct damon_sysfs_watermarks *sysfs_wmarks = sysfs_scheme->watermarks;
2038 	struct damon_sysfs_scheme_filters *sysfs_filters =
2039 		sysfs_scheme->filters;
2040 	struct damos *scheme;
2041 	int err;
2042 
2043 	struct damos_access_pattern pattern = {
2044 		.min_sz_region = access_pattern->sz->min,
2045 		.max_sz_region = access_pattern->sz->max,
2046 		.min_nr_accesses = access_pattern->nr_accesses->min,
2047 		.max_nr_accesses = access_pattern->nr_accesses->max,
2048 		.min_age_region = access_pattern->age->min,
2049 		.max_age_region = access_pattern->age->max,
2050 	};
2051 	struct damos_quota quota = {
2052 		.ms = sysfs_quotas->ms,
2053 		.sz = sysfs_quotas->sz,
2054 		.reset_interval = sysfs_quotas->reset_interval_ms,
2055 		.weight_sz = sysfs_weights->sz,
2056 		.weight_nr_accesses = sysfs_weights->nr_accesses,
2057 		.weight_age = sysfs_weights->age,
2058 	};
2059 	struct damos_watermarks wmarks = {
2060 		.metric = sysfs_wmarks->metric,
2061 		.interval = sysfs_wmarks->interval_us,
2062 		.high = sysfs_wmarks->high,
2063 		.mid = sysfs_wmarks->mid,
2064 		.low = sysfs_wmarks->low,
2065 	};
2066 
2067 	scheme = damon_new_scheme(&pattern, sysfs_scheme->action,
2068 			sysfs_scheme->apply_interval_us, &quota, &wmarks,
2069 			sysfs_scheme->target_nid);
2070 	if (!scheme)
2071 		return NULL;
2072 
2073 	err = damos_sysfs_add_quota_score(sysfs_quotas->goals, &scheme->quota);
2074 	if (err) {
2075 		damon_destroy_scheme(scheme);
2076 		return NULL;
2077 	}
2078 
2079 	err = damon_sysfs_add_scheme_filters(scheme, sysfs_filters);
2080 	if (err) {
2081 		damon_destroy_scheme(scheme);
2082 		return NULL;
2083 	}
2084 	return scheme;
2085 }
2086 
2087 int damon_sysfs_add_schemes(struct damon_ctx *ctx,
2088 		struct damon_sysfs_schemes *sysfs_schemes)
2089 {
2090 	int i;
2091 
2092 	for (i = 0; i < sysfs_schemes->nr; i++) {
2093 		struct damos *scheme, *next;
2094 
2095 		scheme = damon_sysfs_mk_scheme(sysfs_schemes->schemes_arr[i]);
2096 		if (!scheme) {
2097 			damon_for_each_scheme_safe(scheme, next, ctx)
2098 				damon_destroy_scheme(scheme);
2099 			return -ENOMEM;
2100 		}
2101 		damon_add_scheme(ctx, scheme);
2102 	}
2103 	return 0;
2104 }
2105 
2106 void damon_sysfs_schemes_update_stats(
2107 		struct damon_sysfs_schemes *sysfs_schemes,
2108 		struct damon_ctx *ctx)
2109 {
2110 	struct damos *scheme;
2111 	int schemes_idx = 0;
2112 
2113 	damon_for_each_scheme(scheme, ctx) {
2114 		struct damon_sysfs_stats *sysfs_stats;
2115 
2116 		/* user could have removed the scheme sysfs dir */
2117 		if (schemes_idx >= sysfs_schemes->nr)
2118 			break;
2119 
2120 		sysfs_stats = sysfs_schemes->schemes_arr[schemes_idx++]->stats;
2121 		sysfs_stats->nr_tried = scheme->stat.nr_tried;
2122 		sysfs_stats->sz_tried = scheme->stat.sz_tried;
2123 		sysfs_stats->nr_applied = scheme->stat.nr_applied;
2124 		sysfs_stats->sz_applied = scheme->stat.sz_applied;
2125 		sysfs_stats->qt_exceeds = scheme->stat.qt_exceeds;
2126 	}
2127 }
2128 
2129 /*
2130  * damon_sysfs_schemes that need to update its schemes regions dir.  Protected
2131  * by damon_sysfs_lock
2132  */
2133 static struct damon_sysfs_schemes *damon_sysfs_schemes_for_damos_callback;
2134 static int damon_sysfs_schemes_region_idx;
2135 static bool damos_regions_upd_total_bytes_only;
2136 
2137 /*
2138  * DAMON callback that called before damos apply.  While this callback is
2139  * registered, damon_sysfs_lock should be held to ensure the regions
2140  * directories exist.
2141  */
2142 static int damon_sysfs_before_damos_apply(struct damon_ctx *ctx,
2143 		struct damon_target *t, struct damon_region *r,
2144 		struct damos *s)
2145 {
2146 	struct damos *scheme;
2147 	struct damon_sysfs_scheme_regions *sysfs_regions;
2148 	struct damon_sysfs_scheme_region *region;
2149 	struct damon_sysfs_schemes *sysfs_schemes =
2150 		damon_sysfs_schemes_for_damos_callback;
2151 	int schemes_idx = 0;
2152 
2153 	damon_for_each_scheme(scheme, ctx) {
2154 		if (scheme == s)
2155 			break;
2156 		schemes_idx++;
2157 	}
2158 
2159 	/* user could have removed the scheme sysfs dir */
2160 	if (schemes_idx >= sysfs_schemes->nr)
2161 		return 0;
2162 
2163 	sysfs_regions = sysfs_schemes->schemes_arr[schemes_idx]->tried_regions;
2164 	if (sysfs_regions->upd_status == DAMOS_TRIED_REGIONS_UPD_FINISHED)
2165 		return 0;
2166 	if (sysfs_regions->upd_status == DAMOS_TRIED_REGIONS_UPD_IDLE)
2167 		sysfs_regions->upd_status = DAMOS_TRIED_REGIONS_UPD_STARTED;
2168 	sysfs_regions->total_bytes += r->ar.end - r->ar.start;
2169 	if (damos_regions_upd_total_bytes_only)
2170 		return 0;
2171 
2172 	region = damon_sysfs_scheme_region_alloc(r);
2173 	if (!region)
2174 		return 0;
2175 	list_add_tail(&region->list, &sysfs_regions->regions_list);
2176 	sysfs_regions->nr_regions++;
2177 	if (kobject_init_and_add(&region->kobj,
2178 				&damon_sysfs_scheme_region_ktype,
2179 				&sysfs_regions->kobj, "%d",
2180 				damon_sysfs_schemes_region_idx++)) {
2181 		kobject_put(&region->kobj);
2182 	}
2183 	return 0;
2184 }
2185 
2186 /*
2187  * DAMON callback that called after each accesses sampling.  While this
2188  * callback is registered, damon_sysfs_lock should be held to ensure the
2189  * regions directories exist.
2190  */
2191 void damos_sysfs_mark_finished_regions_updates(struct damon_ctx *ctx)
2192 {
2193 	struct damon_sysfs_schemes *sysfs_schemes =
2194 		damon_sysfs_schemes_for_damos_callback;
2195 	struct damon_sysfs_scheme_regions *sysfs_regions;
2196 	int i;
2197 
2198 	for (i = 0; i < sysfs_schemes->nr; i++) {
2199 		sysfs_regions = sysfs_schemes->schemes_arr[i]->tried_regions;
2200 		if (sysfs_regions->upd_status ==
2201 				DAMOS_TRIED_REGIONS_UPD_STARTED ||
2202 				time_after(jiffies,
2203 					sysfs_regions->upd_timeout_jiffies))
2204 			sysfs_regions->upd_status =
2205 				DAMOS_TRIED_REGIONS_UPD_FINISHED;
2206 	}
2207 }
2208 
2209 /* Called from damon_sysfs_cmd_request_callback under damon_sysfs_lock */
2210 int damon_sysfs_schemes_clear_regions(
2211 		struct damon_sysfs_schemes *sysfs_schemes,
2212 		struct damon_ctx *ctx)
2213 {
2214 	struct damos *scheme;
2215 	int schemes_idx = 0;
2216 
2217 	damon_for_each_scheme(scheme, ctx) {
2218 		struct damon_sysfs_scheme *sysfs_scheme;
2219 
2220 		/* user could have removed the scheme sysfs dir */
2221 		if (schemes_idx >= sysfs_schemes->nr)
2222 			break;
2223 
2224 		sysfs_scheme = sysfs_schemes->schemes_arr[schemes_idx++];
2225 		damon_sysfs_scheme_regions_rm_dirs(
2226 				sysfs_scheme->tried_regions);
2227 		sysfs_scheme->tried_regions->total_bytes = 0;
2228 	}
2229 	return 0;
2230 }
2231 
2232 static struct damos *damos_sysfs_nth_scheme(int n, struct damon_ctx *ctx)
2233 {
2234 	struct damos *scheme;
2235 	int i = 0;
2236 
2237 	damon_for_each_scheme(scheme, ctx) {
2238 		if (i == n)
2239 			return scheme;
2240 		i++;
2241 	}
2242 	return NULL;
2243 }
2244 
2245 static void damos_tried_regions_init_upd_status(
2246 		struct damon_sysfs_schemes *sysfs_schemes,
2247 		struct damon_ctx *ctx)
2248 {
2249 	int i;
2250 	struct damos *scheme;
2251 	struct damon_sysfs_scheme_regions *sysfs_regions;
2252 
2253 	for (i = 0; i < sysfs_schemes->nr; i++) {
2254 		sysfs_regions = sysfs_schemes->schemes_arr[i]->tried_regions;
2255 		scheme = damos_sysfs_nth_scheme(i, ctx);
2256 		if (!scheme) {
2257 			sysfs_regions->upd_status =
2258 				DAMOS_TRIED_REGIONS_UPD_FINISHED;
2259 			continue;
2260 		}
2261 		sysfs_regions->upd_status = DAMOS_TRIED_REGIONS_UPD_IDLE;
2262 		sysfs_regions->upd_timeout_jiffies = jiffies +
2263 			2 * usecs_to_jiffies(scheme->apply_interval_us ?
2264 					scheme->apply_interval_us :
2265 					ctx->attrs.aggr_interval);
2266 	}
2267 }
2268 
2269 /* Called from damon_sysfs_cmd_request_callback under damon_sysfs_lock */
2270 int damon_sysfs_schemes_update_regions_start(
2271 		struct damon_sysfs_schemes *sysfs_schemes,
2272 		struct damon_ctx *ctx, bool total_bytes_only)
2273 {
2274 	damon_sysfs_schemes_clear_regions(sysfs_schemes, ctx);
2275 	damon_sysfs_schemes_for_damos_callback = sysfs_schemes;
2276 	damos_tried_regions_init_upd_status(sysfs_schemes, ctx);
2277 	damos_regions_upd_total_bytes_only = total_bytes_only;
2278 	ctx->callback.before_damos_apply = damon_sysfs_before_damos_apply;
2279 	return 0;
2280 }
2281 
2282 bool damos_sysfs_regions_upd_done(void)
2283 {
2284 	struct damon_sysfs_schemes *sysfs_schemes =
2285 		damon_sysfs_schemes_for_damos_callback;
2286 	struct damon_sysfs_scheme_regions *sysfs_regions;
2287 	int i;
2288 
2289 	for (i = 0; i < sysfs_schemes->nr; i++) {
2290 		sysfs_regions = sysfs_schemes->schemes_arr[i]->tried_regions;
2291 		if (sysfs_regions->upd_status !=
2292 				DAMOS_TRIED_REGIONS_UPD_FINISHED)
2293 			return false;
2294 	}
2295 	return true;
2296 }
2297 
2298 /*
2299  * Called from damon_sysfs_cmd_request_callback under damon_sysfs_lock.  Caller
2300  * should unlock damon_sysfs_lock which held before
2301  * damon_sysfs_schemes_update_regions_start()
2302  */
2303 int damon_sysfs_schemes_update_regions_stop(struct damon_ctx *ctx)
2304 {
2305 	damon_sysfs_schemes_for_damos_callback = NULL;
2306 	ctx->callback.before_damos_apply = NULL;
2307 	damon_sysfs_schemes_region_idx = 0;
2308 	return 0;
2309 }
2310