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) */ damon_rand(unsigned long l,unsigned long r)23 static 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 */ 33 struct 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 */ 66 struct 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 */ 90 struct 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_MIGRATE_HOT: Migrate the regions prioritizing warmer regions. 109 * @DAMOS_MIGRATE_COLD: Migrate the regions prioritizing colder regions. 110 * @DAMOS_STAT: Do nothing but count the stat. 111 * @NR_DAMOS_ACTIONS: Total number of DAMOS actions 112 * 113 * The support of each action is up to running &struct damon_operations. 114 * &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR supports all actions except 115 * &enum DAMOS_LRU_PRIO and &enum DAMOS_LRU_DEPRIO. &enum DAMON_OPS_PADDR 116 * supports only &enum DAMOS_PAGEOUT, &enum DAMOS_LRU_PRIO, &enum 117 * DAMOS_LRU_DEPRIO, and &DAMOS_STAT. 118 */ 119 enum damos_action { 120 DAMOS_WILLNEED, 121 DAMOS_COLD, 122 DAMOS_PAGEOUT, 123 DAMOS_HUGEPAGE, 124 DAMOS_NOHUGEPAGE, 125 DAMOS_LRU_PRIO, 126 DAMOS_LRU_DEPRIO, 127 DAMOS_MIGRATE_HOT, 128 DAMOS_MIGRATE_COLD, 129 DAMOS_STAT, /* Do nothing but only record the stat */ 130 NR_DAMOS_ACTIONS, 131 }; 132 133 /** 134 * enum damos_quota_goal_metric - Represents the metric to be used as the goal 135 * 136 * @DAMOS_QUOTA_USER_INPUT: User-input value. 137 * @DAMOS_QUOTA_SOME_MEM_PSI_US: System level some memory PSI in us. 138 * @NR_DAMOS_QUOTA_GOAL_METRICS: Number of DAMOS quota goal metrics. 139 * 140 * Metrics equal to larger than @NR_DAMOS_QUOTA_GOAL_METRICS are unsupported. 141 */ 142 enum damos_quota_goal_metric { 143 DAMOS_QUOTA_USER_INPUT, 144 DAMOS_QUOTA_SOME_MEM_PSI_US, 145 NR_DAMOS_QUOTA_GOAL_METRICS, 146 }; 147 148 /** 149 * struct damos_quota_goal - DAMOS scheme quota auto-tuning goal. 150 * @metric: Metric to be used for representing the goal. 151 * @target_value: Target value of @metric to achieve with the tuning. 152 * @current_value: Current value of @metric. 153 * @last_psi_total: Last measured total PSI 154 * @list: List head for siblings. 155 * 156 * Data structure for getting the current score of the quota tuning goal. The 157 * score is calculated by how close @current_value and @target_value are. Then 158 * the score is entered to DAMON's internal feedback loop mechanism to get the 159 * auto-tuned quota. 160 * 161 * If @metric is DAMOS_QUOTA_USER_INPUT, @current_value should be manually 162 * entered by the user, probably inside the kdamond callbacks. Otherwise, 163 * DAMON sets @current_value with self-measured value of @metric. 164 */ 165 struct damos_quota_goal { 166 enum damos_quota_goal_metric metric; 167 unsigned long target_value; 168 unsigned long current_value; 169 /* metric-dependent fields */ 170 union { 171 u64 last_psi_total; 172 }; 173 struct list_head list; 174 }; 175 176 /** 177 * struct damos_quota - Controls the aggressiveness of the given scheme. 178 * @reset_interval: Charge reset interval in milliseconds. 179 * @ms: Maximum milliseconds that the scheme can use. 180 * @sz: Maximum bytes of memory that the action can be applied. 181 * @goals: Head of quota tuning goals (&damos_quota_goal) list. 182 * @esz: Effective size quota in bytes. 183 * 184 * @weight_sz: Weight of the region's size for prioritization. 185 * @weight_nr_accesses: Weight of the region's nr_accesses for prioritization. 186 * @weight_age: Weight of the region's age for prioritization. 187 * 188 * To avoid consuming too much CPU time or IO resources for applying the 189 * &struct damos->action to large memory, DAMON allows users to set time and/or 190 * size quotas. The quotas can be set by writing non-zero values to &ms and 191 * &sz, respectively. If the time quota is set, DAMON tries to use only up to 192 * &ms milliseconds within &reset_interval for applying the action. If the 193 * size quota is set, DAMON tries to apply the action only up to &sz bytes 194 * within &reset_interval. 195 * 196 * Internally, the time quota is transformed to a size quota using estimated 197 * throughput of the scheme's action. DAMON then compares it against &sz and 198 * uses smaller one as the effective quota. 199 * 200 * If @goals is not empt, DAMON calculates yet another size quota based on the 201 * goals using its internal feedback loop algorithm, for every @reset_interval. 202 * Then, if the new size quota is smaller than the effective quota, it uses the 203 * new size quota as the effective quota. 204 * 205 * The resulting effective size quota in bytes is set to @esz. 206 * 207 * For selecting regions within the quota, DAMON prioritizes current scheme's 208 * target memory regions using the &struct damon_operations->get_scheme_score. 209 * You could customize the prioritization logic by setting &weight_sz, 210 * &weight_nr_accesses, and &weight_age, because monitoring operations are 211 * encouraged to respect those. 212 */ 213 struct damos_quota { 214 unsigned long reset_interval; 215 unsigned long ms; 216 unsigned long sz; 217 struct list_head goals; 218 unsigned long esz; 219 220 unsigned int weight_sz; 221 unsigned int weight_nr_accesses; 222 unsigned int weight_age; 223 224 /* private: */ 225 /* For throughput estimation */ 226 unsigned long total_charged_sz; 227 unsigned long total_charged_ns; 228 229 /* For charging the quota */ 230 unsigned long charged_sz; 231 unsigned long charged_from; 232 struct damon_target *charge_target_from; 233 unsigned long charge_addr_from; 234 235 /* For prioritization */ 236 unsigned int min_score; 237 238 /* For feedback loop */ 239 unsigned long esz_bp; 240 }; 241 242 /** 243 * enum damos_wmark_metric - Represents the watermark metric. 244 * 245 * @DAMOS_WMARK_NONE: Ignore the watermarks of the given scheme. 246 * @DAMOS_WMARK_FREE_MEM_RATE: Free memory rate of the system in [0,1000]. 247 * @NR_DAMOS_WMARK_METRICS: Total number of DAMOS watermark metrics 248 */ 249 enum damos_wmark_metric { 250 DAMOS_WMARK_NONE, 251 DAMOS_WMARK_FREE_MEM_RATE, 252 NR_DAMOS_WMARK_METRICS, 253 }; 254 255 /** 256 * struct damos_watermarks - Controls when a given scheme should be activated. 257 * @metric: Metric for the watermarks. 258 * @interval: Watermarks check time interval in microseconds. 259 * @high: High watermark. 260 * @mid: Middle watermark. 261 * @low: Low watermark. 262 * 263 * If &metric is &DAMOS_WMARK_NONE, the scheme is always active. Being active 264 * means DAMON does monitoring and applying the action of the scheme to 265 * appropriate memory regions. Else, DAMON checks &metric of the system for at 266 * least every &interval microseconds and works as below. 267 * 268 * If &metric is higher than &high, the scheme is inactivated. If &metric is 269 * between &mid and &low, the scheme is activated. If &metric is lower than 270 * &low, the scheme is inactivated. 271 */ 272 struct damos_watermarks { 273 enum damos_wmark_metric metric; 274 unsigned long interval; 275 unsigned long high; 276 unsigned long mid; 277 unsigned long low; 278 279 /* private: */ 280 bool activated; 281 }; 282 283 /** 284 * struct damos_stat - Statistics on a given scheme. 285 * @nr_tried: Total number of regions that the scheme is tried to be applied. 286 * @sz_tried: Total size of regions that the scheme is tried to be applied. 287 * @nr_applied: Total number of regions that the scheme is applied. 288 * @sz_applied: Total size of regions that the scheme is applied. 289 * @qt_exceeds: Total number of times the quota of the scheme has exceeded. 290 */ 291 struct damos_stat { 292 unsigned long nr_tried; 293 unsigned long sz_tried; 294 unsigned long nr_applied; 295 unsigned long sz_applied; 296 unsigned long qt_exceeds; 297 }; 298 299 /** 300 * enum damos_filter_type - Type of memory for &struct damos_filter 301 * @DAMOS_FILTER_TYPE_ANON: Anonymous pages. 302 * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages. 303 * @DAMOS_FILTER_TYPE_YOUNG: Recently accessed pages. 304 * @DAMOS_FILTER_TYPE_ADDR: Address range. 305 * @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target. 306 * @NR_DAMOS_FILTER_TYPES: Number of filter types. 307 * 308 * The anon pages type and memcg type filters are handled by underlying 309 * &struct damon_operations as a part of scheme action trying, and therefore 310 * accounted as 'tried'. In contrast, other types are handled by core layer 311 * before trying of the action and therefore not accounted as 'tried'. 312 * 313 * The support of the filters that handled by &struct damon_operations depend 314 * on the running &struct damon_operations. 315 * &enum DAMON_OPS_PADDR supports both anon pages type and memcg type filters, 316 * while &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR don't support any of 317 * the two types. 318 */ 319 enum damos_filter_type { 320 DAMOS_FILTER_TYPE_ANON, 321 DAMOS_FILTER_TYPE_MEMCG, 322 DAMOS_FILTER_TYPE_YOUNG, 323 DAMOS_FILTER_TYPE_ADDR, 324 DAMOS_FILTER_TYPE_TARGET, 325 NR_DAMOS_FILTER_TYPES, 326 }; 327 328 /** 329 * struct damos_filter - DAMOS action target memory filter. 330 * @type: Type of the page. 331 * @matching: If the matching page should filtered out or in. 332 * @memcg_id: Memcg id of the question if @type is DAMOS_FILTER_MEMCG. 333 * @addr_range: Address range if @type is DAMOS_FILTER_TYPE_ADDR. 334 * @target_idx: Index of the &struct damon_target of 335 * &damon_ctx->adaptive_targets if @type is 336 * DAMOS_FILTER_TYPE_TARGET. 337 * @list: List head for siblings. 338 * 339 * Before applying the &damos->action to a memory region, DAMOS checks if each 340 * page of the region matches to this and avoid applying the action if so. 341 * Support of each filter type depends on the running &struct damon_operations 342 * and the type. Refer to &enum damos_filter_type for more detai. 343 */ 344 struct damos_filter { 345 enum damos_filter_type type; 346 bool matching; 347 union { 348 unsigned short memcg_id; 349 struct damon_addr_range addr_range; 350 int target_idx; 351 }; 352 struct list_head list; 353 }; 354 355 /** 356 * struct damos_access_pattern - Target access pattern of the given scheme. 357 * @min_sz_region: Minimum size of target regions. 358 * @max_sz_region: Maximum size of target regions. 359 * @min_nr_accesses: Minimum ``->nr_accesses`` of target regions. 360 * @max_nr_accesses: Maximum ``->nr_accesses`` of target regions. 361 * @min_age_region: Minimum age of target regions. 362 * @max_age_region: Maximum age of target regions. 363 */ 364 struct damos_access_pattern { 365 unsigned long min_sz_region; 366 unsigned long max_sz_region; 367 unsigned int min_nr_accesses; 368 unsigned int max_nr_accesses; 369 unsigned int min_age_region; 370 unsigned int max_age_region; 371 }; 372 373 /** 374 * struct damos - Represents a Data Access Monitoring-based Operation Scheme. 375 * @pattern: Access pattern of target regions. 376 * @action: &damo_action to be applied to the target regions. 377 * @apply_interval_us: The time between applying the @action. 378 * @quota: Control the aggressiveness of this scheme. 379 * @wmarks: Watermarks for automated (in)activation of this scheme. 380 * @target_nid: Destination node if @action is "migrate_{hot,cold}". 381 * @filters: Additional set of &struct damos_filter for &action. 382 * @stat: Statistics of this scheme. 383 * @list: List head for siblings. 384 * 385 * For each @apply_interval_us, DAMON finds regions which fit in the 386 * &pattern and applies &action to those. To avoid consuming too much 387 * CPU time or IO resources for the &action, "a is used. 388 * 389 * If @apply_interval_us is zero, &damon_attrs->aggr_interval is used instead. 390 * 391 * To do the work only when needed, schemes can be activated for specific 392 * system situations using &wmarks. If all schemes that registered to the 393 * monitoring context are inactive, DAMON stops monitoring either, and just 394 * repeatedly checks the watermarks. 395 * 396 * @target_nid is used to set the migration target node for migrate_hot or 397 * migrate_cold actions, which means it's only meaningful when @action is either 398 * "migrate_hot" or "migrate_cold". 399 * 400 * Before applying the &action to a memory region, &struct damon_operations 401 * implementation could check pages of the region and skip &action to respect 402 * &filters 403 * 404 * After applying the &action to each region, &stat_count and &stat_sz is 405 * updated to reflect the number of regions and total size of regions that the 406 * &action is applied. 407 */ 408 struct damos { 409 struct damos_access_pattern pattern; 410 enum damos_action action; 411 unsigned long apply_interval_us; 412 /* private: internal use only */ 413 /* 414 * number of sample intervals that should be passed before applying 415 * @action 416 */ 417 unsigned long next_apply_sis; 418 /* public: */ 419 struct damos_quota quota; 420 struct damos_watermarks wmarks; 421 union { 422 int target_nid; 423 }; 424 struct list_head filters; 425 struct damos_stat stat; 426 struct list_head list; 427 }; 428 429 /** 430 * enum damon_ops_id - Identifier for each monitoring operations implementation 431 * 432 * @DAMON_OPS_VADDR: Monitoring operations for virtual address spaces 433 * @DAMON_OPS_FVADDR: Monitoring operations for only fixed ranges of virtual 434 * address spaces 435 * @DAMON_OPS_PADDR: Monitoring operations for the physical address space 436 * @NR_DAMON_OPS: Number of monitoring operations implementations 437 */ 438 enum damon_ops_id { 439 DAMON_OPS_VADDR, 440 DAMON_OPS_FVADDR, 441 DAMON_OPS_PADDR, 442 NR_DAMON_OPS, 443 }; 444 445 struct damon_ctx; 446 447 /** 448 * struct damon_operations - Monitoring operations for given use cases. 449 * 450 * @id: Identifier of this operations set. 451 * @init: Initialize operations-related data structures. 452 * @update: Update operations-related data structures. 453 * @prepare_access_checks: Prepare next access check of target regions. 454 * @check_accesses: Check the accesses to target regions. 455 * @reset_aggregated: Reset aggregated accesses monitoring results. 456 * @get_scheme_score: Get the score of a region for a scheme. 457 * @apply_scheme: Apply a DAMON-based operation scheme. 458 * @target_valid: Determine if the target is valid. 459 * @cleanup: Clean up the context. 460 * 461 * DAMON can be extended for various address spaces and usages. For this, 462 * users should register the low level operations for their target address 463 * space and usecase via the &damon_ctx.ops. Then, the monitoring thread 464 * (&damon_ctx.kdamond) calls @init and @prepare_access_checks before starting 465 * the monitoring, @update after each &damon_attrs.ops_update_interval, and 466 * @check_accesses, @target_valid and @prepare_access_checks after each 467 * &damon_attrs.sample_interval. Finally, @reset_aggregated is called after 468 * each &damon_attrs.aggr_interval. 469 * 470 * Each &struct damon_operations instance having valid @id can be registered 471 * via damon_register_ops() and selected by damon_select_ops() later. 472 * @init should initialize operations-related data structures. For example, 473 * this could be used to construct proper monitoring target regions and link 474 * those to @damon_ctx.adaptive_targets. 475 * @update should update the operations-related data structures. For example, 476 * this could be used to update monitoring target regions for current status. 477 * @prepare_access_checks should manipulate the monitoring regions to be 478 * prepared for the next access check. 479 * @check_accesses should check the accesses to each region that made after the 480 * last preparation and update the number of observed accesses of each region. 481 * It should also return max number of observed accesses that made as a result 482 * of its update. The value will be used for regions adjustment threshold. 483 * @reset_aggregated should reset the access monitoring results that aggregated 484 * by @check_accesses. 485 * @get_scheme_score should return the priority score of a region for a scheme 486 * as an integer in [0, &DAMOS_MAX_SCORE]. 487 * @apply_scheme is called from @kdamond when a region for user provided 488 * DAMON-based operation scheme is found. It should apply the scheme's action 489 * to the region and return bytes of the region that the action is successfully 490 * applied. 491 * @target_valid should check whether the target is still valid for the 492 * monitoring. 493 * @cleanup is called from @kdamond just before its termination. 494 */ 495 struct damon_operations { 496 enum damon_ops_id id; 497 void (*init)(struct damon_ctx *context); 498 void (*update)(struct damon_ctx *context); 499 void (*prepare_access_checks)(struct damon_ctx *context); 500 unsigned int (*check_accesses)(struct damon_ctx *context); 501 void (*reset_aggregated)(struct damon_ctx *context); 502 int (*get_scheme_score)(struct damon_ctx *context, 503 struct damon_target *t, struct damon_region *r, 504 struct damos *scheme); 505 unsigned long (*apply_scheme)(struct damon_ctx *context, 506 struct damon_target *t, struct damon_region *r, 507 struct damos *scheme); 508 bool (*target_valid)(struct damon_target *t); 509 void (*cleanup)(struct damon_ctx *context); 510 }; 511 512 /** 513 * struct damon_callback - Monitoring events notification callbacks. 514 * 515 * @before_start: Called before starting the monitoring. 516 * @after_wmarks_check: Called after each schemes' watermarks check. 517 * @after_sampling: Called after each sampling. 518 * @after_aggregation: Called after each aggregation. 519 * @before_damos_apply: Called before applying DAMOS action. 520 * @before_terminate: Called before terminating the monitoring. 521 * @private: User private data. 522 * 523 * The monitoring thread (&damon_ctx.kdamond) calls @before_start and 524 * @before_terminate just before starting and finishing the monitoring, 525 * respectively. Therefore, those are good places for installing and cleaning 526 * @private. 527 * 528 * The monitoring thread calls @after_wmarks_check after each DAMON-based 529 * operation schemes' watermarks check. If users need to make changes to the 530 * attributes of the monitoring context while it's deactivated due to the 531 * watermarks, this is the good place to do. 532 * 533 * The monitoring thread calls @after_sampling and @after_aggregation for each 534 * of the sampling intervals and aggregation intervals, respectively. 535 * Therefore, users can safely access the monitoring results without additional 536 * protection. For the reason, users are recommended to use these callback for 537 * the accesses to the results. 538 * 539 * If any callback returns non-zero, monitoring stops. 540 */ 541 struct damon_callback { 542 void *private; 543 544 int (*before_start)(struct damon_ctx *context); 545 int (*after_wmarks_check)(struct damon_ctx *context); 546 int (*after_sampling)(struct damon_ctx *context); 547 int (*after_aggregation)(struct damon_ctx *context); 548 int (*before_damos_apply)(struct damon_ctx *context, 549 struct damon_target *target, 550 struct damon_region *region, 551 struct damos *scheme); 552 void (*before_terminate)(struct damon_ctx *context); 553 }; 554 555 /** 556 * struct damon_attrs - Monitoring attributes for accuracy/overhead control. 557 * 558 * @sample_interval: The time between access samplings. 559 * @aggr_interval: The time between monitor results aggregations. 560 * @ops_update_interval: The time between monitoring operations updates. 561 * @min_nr_regions: The minimum number of adaptive monitoring 562 * regions. 563 * @max_nr_regions: The maximum number of adaptive monitoring 564 * regions. 565 * 566 * For each @sample_interval, DAMON checks whether each region is accessed or 567 * not during the last @sample_interval. If such access is found, DAMON 568 * aggregates the information by increasing &damon_region->nr_accesses for 569 * @aggr_interval time. For each @aggr_interval, the count is reset. DAMON 570 * also checks whether the target memory regions need update (e.g., by 571 * ``mmap()`` calls from the application, in case of virtual memory monitoring) 572 * and applies the changes for each @ops_update_interval. All time intervals 573 * are in micro-seconds. Please refer to &struct damon_operations and &struct 574 * damon_callback for more detail. 575 */ 576 struct damon_attrs { 577 unsigned long sample_interval; 578 unsigned long aggr_interval; 579 unsigned long ops_update_interval; 580 unsigned long min_nr_regions; 581 unsigned long max_nr_regions; 582 }; 583 584 /** 585 * struct damon_ctx - Represents a context for each monitoring. This is the 586 * main interface that allows users to set the attributes and get the results 587 * of the monitoring. 588 * 589 * @attrs: Monitoring attributes for accuracy/overhead control. 590 * @kdamond: Kernel thread who does the monitoring. 591 * @kdamond_lock: Mutex for the synchronizations with @kdamond. 592 * 593 * For each monitoring context, one kernel thread for the monitoring is 594 * created. The pointer to the thread is stored in @kdamond. 595 * 596 * Once started, the monitoring thread runs until explicitly required to be 597 * terminated or every monitoring target is invalid. The validity of the 598 * targets is checked via the &damon_operations.target_valid of @ops. The 599 * termination can also be explicitly requested by calling damon_stop(). 600 * The thread sets @kdamond to NULL when it terminates. Therefore, users can 601 * know whether the monitoring is ongoing or terminated by reading @kdamond. 602 * Reads and writes to @kdamond from outside of the monitoring thread must 603 * be protected by @kdamond_lock. 604 * 605 * Note that the monitoring thread protects only @kdamond via @kdamond_lock. 606 * Accesses to other fields must be protected by themselves. 607 * 608 * @ops: Set of monitoring operations for given use cases. 609 * @callback: Set of callbacks for monitoring events notifications. 610 * 611 * @adaptive_targets: Head of monitoring targets (&damon_target) list. 612 * @schemes: Head of schemes (&damos) list. 613 */ 614 struct damon_ctx { 615 struct damon_attrs attrs; 616 617 /* private: internal use only */ 618 /* number of sample intervals that passed since this context started */ 619 unsigned long passed_sample_intervals; 620 /* 621 * number of sample intervals that should be passed before next 622 * aggregation 623 */ 624 unsigned long next_aggregation_sis; 625 /* 626 * number of sample intervals that should be passed before next ops 627 * update 628 */ 629 unsigned long next_ops_update_sis; 630 /* for waiting until the execution of the kdamond_fn is started */ 631 struct completion kdamond_started; 632 /* for scheme quotas prioritization */ 633 unsigned long *regions_score_histogram; 634 635 /* public: */ 636 struct task_struct *kdamond; 637 struct mutex kdamond_lock; 638 639 struct damon_operations ops; 640 struct damon_callback callback; 641 642 struct list_head adaptive_targets; 643 struct list_head schemes; 644 }; 645 damon_next_region(struct damon_region * r)646 static inline struct damon_region *damon_next_region(struct damon_region *r) 647 { 648 return container_of(r->list.next, struct damon_region, list); 649 } 650 damon_prev_region(struct damon_region * r)651 static inline struct damon_region *damon_prev_region(struct damon_region *r) 652 { 653 return container_of(r->list.prev, struct damon_region, list); 654 } 655 damon_last_region(struct damon_target * t)656 static inline struct damon_region *damon_last_region(struct damon_target *t) 657 { 658 return list_last_entry(&t->regions_list, struct damon_region, list); 659 } 660 damon_first_region(struct damon_target * t)661 static inline struct damon_region *damon_first_region(struct damon_target *t) 662 { 663 return list_first_entry(&t->regions_list, struct damon_region, list); 664 } 665 damon_sz_region(struct damon_region * r)666 static inline unsigned long damon_sz_region(struct damon_region *r) 667 { 668 return r->ar.end - r->ar.start; 669 } 670 671 672 #define damon_for_each_region(r, t) \ 673 list_for_each_entry(r, &t->regions_list, list) 674 675 #define damon_for_each_region_from(r, t) \ 676 list_for_each_entry_from(r, &t->regions_list, list) 677 678 #define damon_for_each_region_safe(r, next, t) \ 679 list_for_each_entry_safe(r, next, &t->regions_list, list) 680 681 #define damon_for_each_target(t, ctx) \ 682 list_for_each_entry(t, &(ctx)->adaptive_targets, list) 683 684 #define damon_for_each_target_safe(t, next, ctx) \ 685 list_for_each_entry_safe(t, next, &(ctx)->adaptive_targets, list) 686 687 #define damon_for_each_scheme(s, ctx) \ 688 list_for_each_entry(s, &(ctx)->schemes, list) 689 690 #define damon_for_each_scheme_safe(s, next, ctx) \ 691 list_for_each_entry_safe(s, next, &(ctx)->schemes, list) 692 693 #define damos_for_each_quota_goal(goal, quota) \ 694 list_for_each_entry(goal, "a->goals, list) 695 696 #define damos_for_each_quota_goal_safe(goal, next, quota) \ 697 list_for_each_entry_safe(goal, next, &(quota)->goals, list) 698 699 #define damos_for_each_filter(f, scheme) \ 700 list_for_each_entry(f, &(scheme)->filters, list) 701 702 #define damos_for_each_filter_safe(f, next, scheme) \ 703 list_for_each_entry_safe(f, next, &(scheme)->filters, list) 704 705 #ifdef CONFIG_DAMON 706 707 struct damon_region *damon_new_region(unsigned long start, unsigned long end); 708 709 /* 710 * Add a region between two other regions 711 */ damon_insert_region(struct damon_region * r,struct damon_region * prev,struct damon_region * next,struct damon_target * t)712 static inline void damon_insert_region(struct damon_region *r, 713 struct damon_region *prev, struct damon_region *next, 714 struct damon_target *t) 715 { 716 __list_add(&r->list, &prev->list, &next->list); 717 t->nr_regions++; 718 } 719 720 void damon_add_region(struct damon_region *r, struct damon_target *t); 721 void damon_destroy_region(struct damon_region *r, struct damon_target *t); 722 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, 723 unsigned int nr_ranges); 724 void damon_update_region_access_rate(struct damon_region *r, bool accessed, 725 struct damon_attrs *attrs); 726 727 struct damos_filter *damos_new_filter(enum damos_filter_type type, 728 bool matching); 729 void damos_add_filter(struct damos *s, struct damos_filter *f); 730 void damos_destroy_filter(struct damos_filter *f); 731 732 struct damos_quota_goal *damos_new_quota_goal( 733 enum damos_quota_goal_metric metric, 734 unsigned long target_value); 735 void damos_add_quota_goal(struct damos_quota *q, struct damos_quota_goal *g); 736 void damos_destroy_quota_goal(struct damos_quota_goal *goal); 737 738 struct damos *damon_new_scheme(struct damos_access_pattern *pattern, 739 enum damos_action action, 740 unsigned long apply_interval_us, 741 struct damos_quota *quota, 742 struct damos_watermarks *wmarks, 743 int target_nid); 744 void damon_add_scheme(struct damon_ctx *ctx, struct damos *s); 745 void damon_destroy_scheme(struct damos *s); 746 int damos_commit_quota_goals(struct damos_quota *dst, struct damos_quota *src); 747 748 struct damon_target *damon_new_target(void); 749 void damon_add_target(struct damon_ctx *ctx, struct damon_target *t); 750 bool damon_targets_empty(struct damon_ctx *ctx); 751 void damon_free_target(struct damon_target *t); 752 void damon_destroy_target(struct damon_target *t); 753 unsigned int damon_nr_regions(struct damon_target *t); 754 755 struct damon_ctx *damon_new_ctx(void); 756 void damon_destroy_ctx(struct damon_ctx *ctx); 757 int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs); 758 void damon_set_schemes(struct damon_ctx *ctx, 759 struct damos **schemes, ssize_t nr_schemes); 760 int damon_commit_ctx(struct damon_ctx *old_ctx, struct damon_ctx *new_ctx); 761 int damon_nr_running_ctxs(void); 762 bool damon_is_registered_ops(enum damon_ops_id id); 763 int damon_register_ops(struct damon_operations *ops); 764 int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id); 765 damon_target_has_pid(const struct damon_ctx * ctx)766 static inline bool damon_target_has_pid(const struct damon_ctx *ctx) 767 { 768 return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR; 769 } 770 damon_max_nr_accesses(const struct damon_attrs * attrs)771 static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs) 772 { 773 /* {aggr,sample}_interval are unsigned long, hence could overflow */ 774 return min(attrs->aggr_interval / attrs->sample_interval, 775 (unsigned long)UINT_MAX); 776 } 777 778 779 int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive); 780 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs); 781 782 int damon_set_region_biggest_system_ram_default(struct damon_target *t, 783 unsigned long *start, unsigned long *end); 784 785 #endif /* CONFIG_DAMON */ 786 787 #endif /* _DAMON_H */ 788