mm/damon/sysfs-schemes.c

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