1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * DAMON api 4 * 5 * Author: SeongJae Park <sj@kernel.org> 6 */ 7 8#ifndef _DAMON_H_ 9#define _DAMON_H_ 10 11#include <linux/memcontrol.h> 12#include <linux/mutex.h> 13#include <linux/time64.h> 14#include <linux/types.h> 15#include <linux/random.h> 16 17/* Minimal region size. Every damon_region is aligned by this. */ 18#define DAMON_MIN_REGION PAGE_SIZE 19/* Max priority score for DAMON-based operation schemes */ 20#define DAMOS_MAX_SCORE (99) 21 22/* Get a random number in [l, r) */ 23static inline unsigned long damon_rand(unsigned long l, unsigned long r) 24{ 25 return l + get_random_u32_below(r - l); 26} 27 28/** 29 * struct damon_addr_range - Represents an address region of [@start, @end). 30 * @start: Start address of the region (inclusive). 31 * @end: End address of the region (exclusive). 32 */ 33struct damon_addr_range { 34 unsigned long start; 35 unsigned long end; 36}; 37 38/** 39 * struct damon_region - Represents a monitoring target region. 40 * @ar: The address range of the region. 41 * @sampling_addr: Address of the sample for the next access check. 42 * @nr_accesses: Access frequency of this region. 43 * @nr_accesses_bp: @nr_accesses in basis point (0.01%) that updated for 44 * each sampling interval. 45 * @list: List head for siblings. 46 * @age: Age of this region. 47 * 48 * @nr_accesses is reset to zero for every &damon_attrs->aggr_interval and be 49 * increased for every &damon_attrs->sample_interval if an access to the region 50 * during the last sampling interval is found. The update of this field should 51 * not be done with direct access but with the helper function, 52 * damon_update_region_access_rate(). 53 * 54 * @nr_accesses_bp is another representation of @nr_accesses in basis point 55 * (1 in 10,000) that updated for every &damon_attrs->sample_interval in a 56 * manner similar to moving sum. By the algorithm, this value becomes 57 * @nr_accesses * 10000 for every &struct damon_attrs->aggr_interval. This can 58 * be used when the aggregation interval is too huge and therefore cannot wait 59 * for it before getting the access monitoring results. 60 * 61 * @age is initially zero, increased for each aggregation interval, and reset 62 * to zero again if the access frequency is significantly changed. If two 63 * regions are merged into a new region, both @nr_accesses and @age of the new 64 * region are set as region size-weighted average of those of the two regions. 65 */ 66struct damon_region { 67 struct damon_addr_range ar; 68 unsigned long sampling_addr; 69 unsigned int nr_accesses; 70 unsigned int nr_accesses_bp; 71 struct list_head list; 72 73 unsigned int age; 74/* private: Internal value for age calculation. */ 75 unsigned int last_nr_accesses; 76}; 77 78/** 79 * struct damon_target - Represents a monitoring target. 80 * @pid: The PID of the virtual address space to monitor. 81 * @nr_regions: Number of monitoring target regions of this target. 82 * @regions_list: Head of the monitoring target regions of this target. 83 * @list: List head for siblings. 84 * 85 * Each monitoring context could have multiple targets. For example, a context 86 * for virtual memory address spaces could have multiple target processes. The 87 * @pid should be set for appropriate &struct damon_operations including the 88 * virtual address spaces monitoring operations. 89 */ 90struct damon_target { 91 struct pid *pid; 92 unsigned int nr_regions; 93 struct list_head regions_list; 94 struct list_head list; 95}; 96 97/** 98 * enum damos_action - Represents an action of a Data Access Monitoring-based 99 * Operation Scheme. 100 * 101 * @DAMOS_WILLNEED: Call ``madvise()`` for the region with MADV_WILLNEED. 102 * @DAMOS_COLD: Call ``madvise()`` for the region with MADV_COLD. 103 * @DAMOS_PAGEOUT: Call ``madvise()`` for the region with MADV_PAGEOUT. 104 * @DAMOS_HUGEPAGE: Call ``madvise()`` for the region with MADV_HUGEPAGE. 105 * @DAMOS_NOHUGEPAGE: Call ``madvise()`` for the region with MADV_NOHUGEPAGE. 106 * @DAMOS_LRU_PRIO: Prioritize the region on its LRU lists. 107 * @DAMOS_LRU_DEPRIO: Deprioritize the region on its LRU lists. 108 * @DAMOS_STAT: Do nothing but count the stat. 109 * @NR_DAMOS_ACTIONS: Total number of DAMOS actions 110 * 111 * The support of each action is up to running &struct damon_operations. 112 * &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR supports all actions except 113 * &enum DAMOS_LRU_PRIO and &enum DAMOS_LRU_DEPRIO. &enum DAMON_OPS_PADDR 114 * supports only &enum DAMOS_PAGEOUT, &enum DAMOS_LRU_PRIO, &enum 115 * DAMOS_LRU_DEPRIO, and &DAMOS_STAT. 116 */ 117enum damos_action { 118 DAMOS_WILLNEED, 119 DAMOS_COLD, 120 DAMOS_PAGEOUT, 121 DAMOS_HUGEPAGE, 122 DAMOS_NOHUGEPAGE, 123 DAMOS_LRU_PRIO, 124 DAMOS_LRU_DEPRIO, 125 DAMOS_STAT, /* Do nothing but only record the stat */ 126 NR_DAMOS_ACTIONS, 127}; 128 129/** 130 * enum damos_quota_goal_metric - Represents the metric to be used as the goal 131 * 132 * @DAMOS_QUOTA_USER_INPUT: User-input value. 133 * @DAMOS_QUOTA_SOME_MEM_PSI_US: System level some memory PSI in us. 134 * @NR_DAMOS_QUOTA_GOAL_METRICS: Number of DAMOS quota goal metrics. 135 * 136 * Metrics equal to larger than @NR_DAMOS_QUOTA_GOAL_METRICS are unsupported. 137 */ 138enum damos_quota_goal_metric { 139 DAMOS_QUOTA_USER_INPUT, 140 DAMOS_QUOTA_SOME_MEM_PSI_US, 141 NR_DAMOS_QUOTA_GOAL_METRICS, 142}; 143 144/** 145 * struct damos_quota_goal - DAMOS scheme quota auto-tuning goal. 146 * @metric: Metric to be used for representing the goal. 147 * @target_value: Target value of @metric to achieve with the tuning. 148 * @current_value: Current value of @metric. 149 * @last_psi_total: Last measured total PSI 150 * @list: List head for siblings. 151 * 152 * Data structure for getting the current score of the quota tuning goal. The 153 * score is calculated by how close @current_value and @target_value are. Then 154 * the score is entered to DAMON's internal feedback loop mechanism to get the 155 * auto-tuned quota. 156 * 157 * If @metric is DAMOS_QUOTA_USER_INPUT, @current_value should be manually 158 * entered by the user, probably inside the kdamond callbacks. Otherwise, 159 * DAMON sets @current_value with self-measured value of @metric. 160 */ 161struct damos_quota_goal { 162 enum damos_quota_goal_metric metric; 163 unsigned long target_value; 164 unsigned long current_value; 165 /* metric-dependent fields */ 166 union { 167 u64 last_psi_total; 168 }; 169 struct list_head list; 170}; 171 172/** 173 * struct damos_quota - Controls the aggressiveness of the given scheme. 174 * @reset_interval: Charge reset interval in milliseconds. 175 * @ms: Maximum milliseconds that the scheme can use. 176 * @sz: Maximum bytes of memory that the action can be applied. 177 * @goals: Head of quota tuning goals (&damos_quota_goal) list. 178 * @esz: Effective size quota in bytes. 179 * 180 * @weight_sz: Weight of the region's size for prioritization. 181 * @weight_nr_accesses: Weight of the region's nr_accesses for prioritization. 182 * @weight_age: Weight of the region's age for prioritization. 183 * 184 * To avoid consuming too much CPU time or IO resources for applying the 185 * &struct damos->action to large memory, DAMON allows users to set time and/or 186 * size quotas. The quotas can be set by writing non-zero values to &ms and 187 * &sz, respectively. If the time quota is set, DAMON tries to use only up to 188 * &ms milliseconds within &reset_interval for applying the action. If the 189 * size quota is set, DAMON tries to apply the action only up to &sz bytes 190 * within &reset_interval. 191 * 192 * Internally, the time quota is transformed to a size quota using estimated 193 * throughput of the scheme's action. DAMON then compares it against &sz and 194 * uses smaller one as the effective quota. 195 * 196 * If @goals is not empt, DAMON calculates yet another size quota based on the 197 * goals using its internal feedback loop algorithm, for every @reset_interval. 198 * Then, if the new size quota is smaller than the effective quota, it uses the 199 * new size quota as the effective quota. 200 * 201 * The resulting effective size quota in bytes is set to @esz. 202 * 203 * For selecting regions within the quota, DAMON prioritizes current scheme's 204 * target memory regions using the &struct damon_operations->get_scheme_score. 205 * You could customize the prioritization logic by setting &weight_sz, 206 * &weight_nr_accesses, and &weight_age, because monitoring operations are 207 * encouraged to respect those. 208 */ 209struct damos_quota { 210 unsigned long reset_interval; 211 unsigned long ms; 212 unsigned long sz; 213 struct list_head goals; 214 unsigned long esz; 215 216 unsigned int weight_sz; 217 unsigned int weight_nr_accesses; 218 unsigned int weight_age; 219 220/* private: */ 221 /* For throughput estimation */ 222 unsigned long total_charged_sz; 223 unsigned long total_charged_ns; 224 225 /* For charging the quota */ 226 unsigned long charged_sz; 227 unsigned long charged_from; 228 struct damon_target *charge_target_from; 229 unsigned long charge_addr_from; 230 231 /* For prioritization */ 232 unsigned long histogram[DAMOS_MAX_SCORE + 1]; 233 unsigned int min_score; 234 235 /* For feedback loop */ 236 unsigned long esz_bp; 237}; 238 239/** 240 * enum damos_wmark_metric - Represents the watermark metric. 241 * 242 * @DAMOS_WMARK_NONE: Ignore the watermarks of the given scheme. 243 * @DAMOS_WMARK_FREE_MEM_RATE: Free memory rate of the system in [0,1000]. 244 * @NR_DAMOS_WMARK_METRICS: Total number of DAMOS watermark metrics 245 */ 246enum damos_wmark_metric { 247 DAMOS_WMARK_NONE, 248 DAMOS_WMARK_FREE_MEM_RATE, 249 NR_DAMOS_WMARK_METRICS, 250}; 251 252/** 253 * struct damos_watermarks - Controls when a given scheme should be activated. 254 * @metric: Metric for the watermarks. 255 * @interval: Watermarks check time interval in microseconds. 256 * @high: High watermark. 257 * @mid: Middle watermark. 258 * @low: Low watermark. 259 * 260 * If &metric is &DAMOS_WMARK_NONE, the scheme is always active. Being active 261 * means DAMON does monitoring and applying the action of the scheme to 262 * appropriate memory regions. Else, DAMON checks &metric of the system for at 263 * least every &interval microseconds and works as below. 264 * 265 * If &metric is higher than &high, the scheme is inactivated. If &metric is 266 * between &mid and &low, the scheme is activated. If &metric is lower than 267 * &low, the scheme is inactivated. 268 */ 269struct damos_watermarks { 270 enum damos_wmark_metric metric; 271 unsigned long interval; 272 unsigned long high; 273 unsigned long mid; 274 unsigned long low; 275 276/* private: */ 277 bool activated; 278}; 279 280/** 281 * struct damos_stat - Statistics on a given scheme. 282 * @nr_tried: Total number of regions that the scheme is tried to be applied. 283 * @sz_tried: Total size of regions that the scheme is tried to be applied. 284 * @nr_applied: Total number of regions that the scheme is applied. 285 * @sz_applied: Total size of regions that the scheme is applied. 286 * @qt_exceeds: Total number of times the quota of the scheme has exceeded. 287 */ 288struct damos_stat { 289 unsigned long nr_tried; 290 unsigned long sz_tried; 291 unsigned long nr_applied; 292 unsigned long sz_applied; 293 unsigned long qt_exceeds; 294}; 295 296/** 297 * enum damos_filter_type - Type of memory for &struct damos_filter 298 * @DAMOS_FILTER_TYPE_ANON: Anonymous pages. 299 * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages. 300 * @DAMOS_FILTER_TYPE_ADDR: Address range. 301 * @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target. 302 * @NR_DAMOS_FILTER_TYPES: Number of filter types. 303 * 304 * The anon pages type and memcg type filters are handled by underlying 305 * &struct damon_operations as a part of scheme action trying, and therefore 306 * accounted as 'tried'. In contrast, other types are handled by core layer 307 * before trying of the action and therefore not accounted as 'tried'. 308 * 309 * The support of the filters that handled by &struct damon_operations depend 310 * on the running &struct damon_operations. 311 * &enum DAMON_OPS_PADDR supports both anon pages type and memcg type filters, 312 * while &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR don't support any of 313 * the two types. 314 */ 315enum damos_filter_type { 316 DAMOS_FILTER_TYPE_ANON, 317 DAMOS_FILTER_TYPE_MEMCG, 318 DAMOS_FILTER_TYPE_ADDR, 319 DAMOS_FILTER_TYPE_TARGET, 320 NR_DAMOS_FILTER_TYPES, 321}; 322 323/** 324 * struct damos_filter - DAMOS action target memory filter. 325 * @type: Type of the page. 326 * @matching: If the matching page should filtered out or in. 327 * @memcg_id: Memcg id of the question if @type is DAMOS_FILTER_MEMCG. 328 * @addr_range: Address range if @type is DAMOS_FILTER_TYPE_ADDR. 329 * @target_idx: Index of the &struct damon_target of 330 * &damon_ctx->adaptive_targets if @type is 331 * DAMOS_FILTER_TYPE_TARGET. 332 * @list: List head for siblings. 333 * 334 * Before applying the &damos->action to a memory region, DAMOS checks if each 335 * page of the region matches to this and avoid applying the action if so. 336 * Support of each filter type depends on the running &struct damon_operations 337 * and the type. Refer to &enum damos_filter_type for more detai. 338 */ 339struct damos_filter { 340 enum damos_filter_type type; 341 bool matching; 342 union { 343 unsigned short memcg_id; 344 struct damon_addr_range addr_range; 345 int target_idx; 346 }; 347 struct list_head list; 348}; 349 350/** 351 * struct damos_access_pattern - Target access pattern of the given scheme. 352 * @min_sz_region: Minimum size of target regions. 353 * @max_sz_region: Maximum size of target regions. 354 * @min_nr_accesses: Minimum ``->nr_accesses`` of target regions. 355 * @max_nr_accesses: Maximum ``->nr_accesses`` of target regions. 356 * @min_age_region: Minimum age of target regions. 357 * @max_age_region: Maximum age of target regions. 358 */ 359struct damos_access_pattern { 360 unsigned long min_sz_region; 361 unsigned long max_sz_region; 362 unsigned int min_nr_accesses; 363 unsigned int max_nr_accesses; 364 unsigned int min_age_region; 365 unsigned int max_age_region; 366}; 367 368/** 369 * struct damos - Represents a Data Access Monitoring-based Operation Scheme. 370 * @pattern: Access pattern of target regions. 371 * @action: &damo_action to be applied to the target regions. 372 * @apply_interval_us: The time between applying the @action. 373 * @quota: Control the aggressiveness of this scheme. 374 * @wmarks: Watermarks for automated (in)activation of this scheme. 375 * @filters: Additional set of &struct damos_filter for &action. 376 * @stat: Statistics of this scheme. 377 * @list: List head for siblings. 378 * 379 * For each @apply_interval_us, DAMON finds regions which fit in the 380 * &pattern and applies &action to those. To avoid consuming too much 381 * CPU time or IO resources for the &action, "a is used. 382 * 383 * If @apply_interval_us is zero, &damon_attrs->aggr_interval is used instead. 384 * 385 * To do the work only when needed, schemes can be activated for specific 386 * system situations using &wmarks. If all schemes that registered to the 387 * monitoring context are inactive, DAMON stops monitoring either, and just 388 * repeatedly checks the watermarks. 389 * 390 * Before applying the &action to a memory region, &struct damon_operations 391 * implementation could check pages of the region and skip &action to respect 392 * &filters 393 * 394 * After applying the &action to each region, &stat_count and &stat_sz is 395 * updated to reflect the number of regions and total size of regions that the 396 * &action is applied. 397 */ 398struct damos { 399 struct damos_access_pattern pattern; 400 enum damos_action action; 401 unsigned long apply_interval_us; 402/* private: internal use only */ 403 /* 404 * number of sample intervals that should be passed before applying 405 * @action 406 */ 407 unsigned long next_apply_sis; 408/* public: */ 409 struct damos_quota quota; 410 struct damos_watermarks wmarks; 411 struct list_head filters; 412 struct damos_stat stat; 413 struct list_head list; 414}; 415 416/** 417 * enum damon_ops_id - Identifier for each monitoring operations implementation 418 * 419 * @DAMON_OPS_VADDR: Monitoring operations for virtual address spaces 420 * @DAMON_OPS_FVADDR: Monitoring operations for only fixed ranges of virtual 421 * address spaces 422 * @DAMON_OPS_PADDR: Monitoring operations for the physical address space 423 * @NR_DAMON_OPS: Number of monitoring operations implementations 424 */ 425enum damon_ops_id { 426 DAMON_OPS_VADDR, 427 DAMON_OPS_FVADDR, 428 DAMON_OPS_PADDR, 429 NR_DAMON_OPS, 430}; 431 432struct damon_ctx; 433 434/** 435 * struct damon_operations - Monitoring operations for given use cases. 436 * 437 * @id: Identifier of this operations set. 438 * @init: Initialize operations-related data structures. 439 * @update: Update operations-related data structures. 440 * @prepare_access_checks: Prepare next access check of target regions. 441 * @check_accesses: Check the accesses to target regions. 442 * @reset_aggregated: Reset aggregated accesses monitoring results. 443 * @get_scheme_score: Get the score of a region for a scheme. 444 * @apply_scheme: Apply a DAMON-based operation scheme. 445 * @target_valid: Determine if the target is valid. 446 * @cleanup: Clean up the context. 447 * 448 * DAMON can be extended for various address spaces and usages. For this, 449 * users should register the low level operations for their target address 450 * space and usecase via the &damon_ctx.ops. Then, the monitoring thread 451 * (&damon_ctx.kdamond) calls @init and @prepare_access_checks before starting 452 * the monitoring, @update after each &damon_attrs.ops_update_interval, and 453 * @check_accesses, @target_valid and @prepare_access_checks after each 454 * &damon_attrs.sample_interval. Finally, @reset_aggregated is called after 455 * each &damon_attrs.aggr_interval. 456 * 457 * Each &struct damon_operations instance having valid @id can be registered 458 * via damon_register_ops() and selected by damon_select_ops() later. 459 * @init should initialize operations-related data structures. For example, 460 * this could be used to construct proper monitoring target regions and link 461 * those to @damon_ctx.adaptive_targets. 462 * @update should update the operations-related data structures. For example, 463 * this could be used to update monitoring target regions for current status. 464 * @prepare_access_checks should manipulate the monitoring regions to be 465 * prepared for the next access check. 466 * @check_accesses should check the accesses to each region that made after the 467 * last preparation and update the number of observed accesses of each region. 468 * It should also return max number of observed accesses that made as a result 469 * of its update. The value will be used for regions adjustment threshold. 470 * @reset_aggregated should reset the access monitoring results that aggregated 471 * by @check_accesses. 472 * @get_scheme_score should return the priority score of a region for a scheme 473 * as an integer in [0, &DAMOS_MAX_SCORE]. 474 * @apply_scheme is called from @kdamond when a region for user provided 475 * DAMON-based operation scheme is found. It should apply the scheme's action 476 * to the region and return bytes of the region that the action is successfully 477 * applied. 478 * @target_valid should check whether the target is still valid for the 479 * monitoring. 480 * @cleanup is called from @kdamond just before its termination. 481 */ 482struct damon_operations { 483 enum damon_ops_id id; 484 void (*init)(struct damon_ctx *context); 485 void (*update)(struct damon_ctx *context); 486 void (*prepare_access_checks)(struct damon_ctx *context); 487 unsigned int (*check_accesses)(struct damon_ctx *context); 488 void (*reset_aggregated)(struct damon_ctx *context); 489 int (*get_scheme_score)(struct damon_ctx *context, 490 struct damon_target *t, struct damon_region *r, 491 struct damos *scheme); 492 unsigned long (*apply_scheme)(struct damon_ctx *context, 493 struct damon_target *t, struct damon_region *r, 494 struct damos *scheme); 495 bool (*target_valid)(struct damon_target *t); 496 void (*cleanup)(struct damon_ctx *context); 497}; 498 499/** 500 * struct damon_callback - Monitoring events notification callbacks. 501 * 502 * @before_start: Called before starting the monitoring. 503 * @after_wmarks_check: Called after each schemes' watermarks check. 504 * @after_sampling: Called after each sampling. 505 * @after_aggregation: Called after each aggregation. 506 * @before_damos_apply: Called before applying DAMOS action. 507 * @before_terminate: Called before terminating the monitoring. 508 * @private: User private data. 509 * 510 * The monitoring thread (&damon_ctx.kdamond) calls @before_start and 511 * @before_terminate just before starting and finishing the monitoring, 512 * respectively. Therefore, those are good places for installing and cleaning 513 * @private. 514 * 515 * The monitoring thread calls @after_wmarks_check after each DAMON-based 516 * operation schemes' watermarks check. If users need to make changes to the 517 * attributes of the monitoring context while it's deactivated due to the 518 * watermarks, this is the good place to do. 519 * 520 * The monitoring thread calls @after_sampling and @after_aggregation for each 521 * of the sampling intervals and aggregation intervals, respectively. 522 * Therefore, users can safely access the monitoring results without additional 523 * protection. For the reason, users are recommended to use these callback for 524 * the accesses to the results. 525 * 526 * If any callback returns non-zero, monitoring stops. 527 */ 528struct damon_callback { 529 void *private; 530 531 int (*before_start)(struct damon_ctx *context); 532 int (*after_wmarks_check)(struct damon_ctx *context); 533 int (*after_sampling)(struct damon_ctx *context); 534 int (*after_aggregation)(struct damon_ctx *context); 535 int (*before_damos_apply)(struct damon_ctx *context, 536 struct damon_target *target, 537 struct damon_region *region, 538 struct damos *scheme); 539 void (*before_terminate)(struct damon_ctx *context); 540}; 541 542/** 543 * struct damon_attrs - Monitoring attributes for accuracy/overhead control. 544 * 545 * @sample_interval: The time between access samplings. 546 * @aggr_interval: The time between monitor results aggregations. 547 * @ops_update_interval: The time between monitoring operations updates. 548 * @min_nr_regions: The minimum number of adaptive monitoring 549 * regions. 550 * @max_nr_regions: The maximum number of adaptive monitoring 551 * regions. 552 * 553 * For each @sample_interval, DAMON checks whether each region is accessed or 554 * not during the last @sample_interval. If such access is found, DAMON 555 * aggregates the information by increasing &damon_region->nr_accesses for 556 * @aggr_interval time. For each @aggr_interval, the count is reset. DAMON 557 * also checks whether the target memory regions need update (e.g., by 558 * ``mmap()`` calls from the application, in case of virtual memory monitoring) 559 * and applies the changes for each @ops_update_interval. All time intervals 560 * are in micro-seconds. Please refer to &struct damon_operations and &struct 561 * damon_callback for more detail. 562 */ 563struct damon_attrs { 564 unsigned long sample_interval; 565 unsigned long aggr_interval; 566 unsigned long ops_update_interval; 567 unsigned long min_nr_regions; 568 unsigned long max_nr_regions; 569}; 570 571/** 572 * struct damon_ctx - Represents a context for each monitoring. This is the 573 * main interface that allows users to set the attributes and get the results 574 * of the monitoring. 575 * 576 * @attrs: Monitoring attributes for accuracy/overhead control. 577 * @kdamond: Kernel thread who does the monitoring. 578 * @kdamond_lock: Mutex for the synchronizations with @kdamond. 579 * 580 * For each monitoring context, one kernel thread for the monitoring is 581 * created. The pointer to the thread is stored in @kdamond. 582 * 583 * Once started, the monitoring thread runs until explicitly required to be 584 * terminated or every monitoring target is invalid. The validity of the 585 * targets is checked via the &damon_operations.target_valid of @ops. The 586 * termination can also be explicitly requested by calling damon_stop(). 587 * The thread sets @kdamond to NULL when it terminates. Therefore, users can 588 * know whether the monitoring is ongoing or terminated by reading @kdamond. 589 * Reads and writes to @kdamond from outside of the monitoring thread must 590 * be protected by @kdamond_lock. 591 * 592 * Note that the monitoring thread protects only @kdamond via @kdamond_lock. 593 * Accesses to other fields must be protected by themselves. 594 * 595 * @ops: Set of monitoring operations for given use cases. 596 * @callback: Set of callbacks for monitoring events notifications. 597 * 598 * @adaptive_targets: Head of monitoring targets (&damon_target) list. 599 * @schemes: Head of schemes (&damos) list. 600 */ 601struct damon_ctx { 602 struct damon_attrs attrs; 603 604/* private: internal use only */ 605 /* number of sample intervals that passed since this context started */ 606 unsigned long passed_sample_intervals; 607 /* 608 * number of sample intervals that should be passed before next 609 * aggregation 610 */ 611 unsigned long next_aggregation_sis; 612 /* 613 * number of sample intervals that should be passed before next ops 614 * update 615 */ 616 unsigned long next_ops_update_sis; 617 /* for waiting until the execution of the kdamond_fn is started */ 618 struct completion kdamond_started; 619 620/* public: */ 621 struct task_struct *kdamond; 622 struct mutex kdamond_lock; 623 624 struct damon_operations ops; 625 struct damon_callback callback; 626 627 struct list_head adaptive_targets; 628 struct list_head schemes; 629}; 630 631static inline struct damon_region *damon_next_region(struct damon_region *r) 632{ 633 return container_of(r->list.next, struct damon_region, list); 634} 635 636static inline struct damon_region *damon_prev_region(struct damon_region *r) 637{ 638 return container_of(r->list.prev, struct damon_region, list); 639} 640 641static inline struct damon_region *damon_last_region(struct damon_target *t) 642{ 643 return list_last_entry(&t->regions_list, struct damon_region, list); 644} 645 646static inline struct damon_region *damon_first_region(struct damon_target *t) 647{ 648 return list_first_entry(&t->regions_list, struct damon_region, list); 649} 650 651static inline unsigned long damon_sz_region(struct damon_region *r) 652{ 653 return r->ar.end - r->ar.start; 654} 655 656 657#define damon_for_each_region(r, t) \ 658 list_for_each_entry(r, &t->regions_list, list) 659 660#define damon_for_each_region_from(r, t) \ 661 list_for_each_entry_from(r, &t->regions_list, list) 662 663#define damon_for_each_region_safe(r, next, t) \ 664 list_for_each_entry_safe(r, next, &t->regions_list, list) 665 666#define damon_for_each_target(t, ctx) \ 667 list_for_each_entry(t, &(ctx)->adaptive_targets, list) 668 669#define damon_for_each_target_safe(t, next, ctx) \ 670 list_for_each_entry_safe(t, next, &(ctx)->adaptive_targets, list) 671 672#define damon_for_each_scheme(s, ctx) \ 673 list_for_each_entry(s, &(ctx)->schemes, list) 674 675#define damon_for_each_scheme_safe(s, next, ctx) \ 676 list_for_each_entry_safe(s, next, &(ctx)->schemes, list) 677 678#define damos_for_each_quota_goal(goal, quota) \ 679 list_for_each_entry(goal, "a->goals, list) 680 681#define damos_for_each_quota_goal_safe(goal, next, quota) \ 682 list_for_each_entry_safe(goal, next, &(quota)->goals, list) 683 684#define damos_for_each_filter(f, scheme) \ 685 list_for_each_entry(f, &(scheme)->filters, list) 686 687#define damos_for_each_filter_safe(f, next, scheme) \ 688 list_for_each_entry_safe(f, next, &(scheme)->filters, list) 689 690#ifdef CONFIG_DAMON 691 692struct damon_region *damon_new_region(unsigned long start, unsigned long end); 693 694/* 695 * Add a region between two other regions 696 */ 697static inline void damon_insert_region(struct damon_region *r, 698 struct damon_region *prev, struct damon_region *next, 699 struct damon_target *t) 700{ 701 __list_add(&r->list, &prev->list, &next->list); 702 t->nr_regions++; 703} 704 705void damon_add_region(struct damon_region *r, struct damon_target *t); 706void damon_destroy_region(struct damon_region *r, struct damon_target *t); 707int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, 708 unsigned int nr_ranges); 709void damon_update_region_access_rate(struct damon_region *r, bool accessed, 710 struct damon_attrs *attrs); 711 712struct damos_filter *damos_new_filter(enum damos_filter_type type, 713 bool matching); 714void damos_add_filter(struct damos *s, struct damos_filter *f); 715void damos_destroy_filter(struct damos_filter *f); 716 717struct damos_quota_goal *damos_new_quota_goal( 718 enum damos_quota_goal_metric metric, 719 unsigned long target_value); 720void damos_add_quota_goal(struct damos_quota *q, struct damos_quota_goal *g); 721void damos_destroy_quota_goal(struct damos_quota_goal *goal); 722 723struct damos *damon_new_scheme(struct damos_access_pattern *pattern, 724 enum damos_action action, 725 unsigned long apply_interval_us, 726 struct damos_quota *quota, 727 struct damos_watermarks *wmarks); 728void damon_add_scheme(struct damon_ctx *ctx, struct damos *s); 729void damon_destroy_scheme(struct damos *s); 730 731struct damon_target *damon_new_target(void); 732void damon_add_target(struct damon_ctx *ctx, struct damon_target *t); 733bool damon_targets_empty(struct damon_ctx *ctx); 734void damon_free_target(struct damon_target *t); 735void damon_destroy_target(struct damon_target *t); 736unsigned int damon_nr_regions(struct damon_target *t); 737 738struct damon_ctx *damon_new_ctx(void); 739void damon_destroy_ctx(struct damon_ctx *ctx); 740int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs); 741void damon_set_schemes(struct damon_ctx *ctx, 742 struct damos **schemes, ssize_t nr_schemes); 743int damon_nr_running_ctxs(void); 744bool damon_is_registered_ops(enum damon_ops_id id); 745int damon_register_ops(struct damon_operations *ops); 746int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id); 747 748static inline bool damon_target_has_pid(const struct damon_ctx *ctx) 749{ 750 return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR; 751} 752 753static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs) 754{ 755 /* {aggr,sample}_interval are unsigned long, hence could overflow */ 756 return min(attrs->aggr_interval / attrs->sample_interval, 757 (unsigned long)UINT_MAX); 758} 759 760 761int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive); 762int damon_stop(struct damon_ctx **ctxs, int nr_ctxs); 763 764int damon_set_region_biggest_system_ram_default(struct damon_target *t, 765 unsigned long *start, unsigned long *end); 766 767#endif /* CONFIG_DAMON */ 768 769#endif /* _DAMON_H */ 770