1 /* SPDX-License-Identifier: GPL-2.0 */
5 * Author: SeongJae Park <sjpark@amazon.de>
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>
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)
22 /* Get a random number in [l, r) */
23 static inline unsigned long damon_rand(unsigned long l, unsigned long r)
25 return l + get_random_u32_below(r - l);
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).
33 struct damon_addr_range {
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.
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().
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.
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.
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;
74 /* private: Internal value for age calculation. */
75 unsigned int last_nr_accesses;
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.
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.
92 unsigned int nr_regions;
93 struct list_head regions_list;
94 struct list_head list;
98 * enum damos_action - Represents an action of a Data Access Monitoring-based
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
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.
125 DAMOS_STAT, /* Do nothing but only record the stat */
130 * struct damos_quota - Controls the aggressiveness of the given scheme.
131 * @ms: Maximum milliseconds that the scheme can use.
132 * @sz: Maximum bytes of memory that the action can be applied.
133 * @reset_interval: Charge reset interval in milliseconds.
135 * @weight_sz: Weight of the region's size for prioritization.
136 * @weight_nr_accesses: Weight of the region's nr_accesses for prioritization.
137 * @weight_age: Weight of the region's age for prioritization.
139 * To avoid consuming too much CPU time or IO resources for applying the
140 * &struct damos->action to large memory, DAMON allows users to set time and/or
141 * size quotas. The quotas can be set by writing non-zero values to &ms and
142 * &sz, respectively. If the time quota is set, DAMON tries to use only up to
143 * &ms milliseconds within &reset_interval for applying the action. If the
144 * size quota is set, DAMON tries to apply the action only up to &sz bytes
145 * within &reset_interval.
147 * Internally, the time quota is transformed to a size quota using estimated
148 * throughput of the scheme's action. DAMON then compares it against &sz and
149 * uses smaller one as the effective quota.
151 * For selecting regions within the quota, DAMON prioritizes current scheme's
152 * target memory regions using the &struct damon_operations->get_scheme_score.
153 * You could customize the prioritization logic by setting &weight_sz,
154 * &weight_nr_accesses, and &weight_age, because monitoring operations are
155 * encouraged to respect those.
160 unsigned long reset_interval;
162 unsigned int weight_sz;
163 unsigned int weight_nr_accesses;
164 unsigned int weight_age;
167 /* For throughput estimation */
168 unsigned long total_charged_sz;
169 unsigned long total_charged_ns;
171 unsigned long esz; /* Effective size quota in bytes */
173 /* For charging the quota */
174 unsigned long charged_sz;
175 unsigned long charged_from;
176 struct damon_target *charge_target_from;
177 unsigned long charge_addr_from;
179 /* For prioritization */
180 unsigned long histogram[DAMOS_MAX_SCORE + 1];
181 unsigned int min_score;
185 * enum damos_wmark_metric - Represents the watermark metric.
187 * @DAMOS_WMARK_NONE: Ignore the watermarks of the given scheme.
188 * @DAMOS_WMARK_FREE_MEM_RATE: Free memory rate of the system in [0,1000].
189 * @NR_DAMOS_WMARK_METRICS: Total number of DAMOS watermark metrics
191 enum damos_wmark_metric {
193 DAMOS_WMARK_FREE_MEM_RATE,
194 NR_DAMOS_WMARK_METRICS,
198 * struct damos_watermarks - Controls when a given scheme should be activated.
199 * @metric: Metric for the watermarks.
200 * @interval: Watermarks check time interval in microseconds.
201 * @high: High watermark.
202 * @mid: Middle watermark.
203 * @low: Low watermark.
205 * If &metric is &DAMOS_WMARK_NONE, the scheme is always active. Being active
206 * means DAMON does monitoring and applying the action of the scheme to
207 * appropriate memory regions. Else, DAMON checks &metric of the system for at
208 * least every &interval microseconds and works as below.
210 * If &metric is higher than &high, the scheme is inactivated. If &metric is
211 * between &mid and &low, the scheme is activated. If &metric is lower than
212 * &low, the scheme is inactivated.
214 struct damos_watermarks {
215 enum damos_wmark_metric metric;
216 unsigned long interval;
226 * struct damos_stat - Statistics on a given scheme.
227 * @nr_tried: Total number of regions that the scheme is tried to be applied.
228 * @sz_tried: Total size of regions that the scheme is tried to be applied.
229 * @nr_applied: Total number of regions that the scheme is applied.
230 * @sz_applied: Total size of regions that the scheme is applied.
231 * @qt_exceeds: Total number of times the quota of the scheme has exceeded.
234 unsigned long nr_tried;
235 unsigned long sz_tried;
236 unsigned long nr_applied;
237 unsigned long sz_applied;
238 unsigned long qt_exceeds;
242 * enum damos_filter_type - Type of memory for &struct damos_filter
243 * @DAMOS_FILTER_TYPE_ANON: Anonymous pages.
244 * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages.
245 * @DAMOS_FILTER_TYPE_ADDR: Address range.
246 * @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target.
247 * @NR_DAMOS_FILTER_TYPES: Number of filter types.
249 * The anon pages type and memcg type filters are handled by underlying
250 * &struct damon_operations as a part of scheme action trying, and therefore
251 * accounted as 'tried'. In contrast, other types are handled by core layer
252 * before trying of the action and therefore not accounted as 'tried'.
254 * The support of the filters that handled by &struct damon_operations depend
255 * on the running &struct damon_operations.
256 * &enum DAMON_OPS_PADDR supports both anon pages type and memcg type filters,
257 * while &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR don't support any of
260 enum damos_filter_type {
261 DAMOS_FILTER_TYPE_ANON,
262 DAMOS_FILTER_TYPE_MEMCG,
263 DAMOS_FILTER_TYPE_ADDR,
264 DAMOS_FILTER_TYPE_TARGET,
265 NR_DAMOS_FILTER_TYPES,
269 * struct damos_filter - DAMOS action target memory filter.
270 * @type: Type of the page.
271 * @matching: If the matching page should filtered out or in.
272 * @memcg_id: Memcg id of the question if @type is DAMOS_FILTER_MEMCG.
273 * @addr_range: Address range if @type is DAMOS_FILTER_TYPE_ADDR.
274 * @target_idx: Index of the &struct damon_target of
275 * &damon_ctx->adaptive_targets if @type is
276 * DAMOS_FILTER_TYPE_TARGET.
277 * @list: List head for siblings.
279 * Before applying the &damos->action to a memory region, DAMOS checks if each
280 * page of the region matches to this and avoid applying the action if so.
281 * Support of each filter type depends on the running &struct damon_operations
282 * and the type. Refer to &enum damos_filter_type for more detai.
284 struct damos_filter {
285 enum damos_filter_type type;
288 unsigned short memcg_id;
289 struct damon_addr_range addr_range;
292 struct list_head list;
296 * struct damos_access_pattern - Target access pattern of the given scheme.
297 * @min_sz_region: Minimum size of target regions.
298 * @max_sz_region: Maximum size of target regions.
299 * @min_nr_accesses: Minimum ``->nr_accesses`` of target regions.
300 * @max_nr_accesses: Maximum ``->nr_accesses`` of target regions.
301 * @min_age_region: Minimum age of target regions.
302 * @max_age_region: Maximum age of target regions.
304 struct damos_access_pattern {
305 unsigned long min_sz_region;
306 unsigned long max_sz_region;
307 unsigned int min_nr_accesses;
308 unsigned int max_nr_accesses;
309 unsigned int min_age_region;
310 unsigned int max_age_region;
314 * struct damos - Represents a Data Access Monitoring-based Operation Scheme.
315 * @pattern: Access pattern of target regions.
316 * @action: &damo_action to be applied to the target regions.
317 * @apply_interval_us: The time between applying the @action.
318 * @quota: Control the aggressiveness of this scheme.
319 * @wmarks: Watermarks for automated (in)activation of this scheme.
320 * @filters: Additional set of &struct damos_filter for &action.
321 * @stat: Statistics of this scheme.
322 * @list: List head for siblings.
324 * For each @apply_interval_us, DAMON finds regions which fit in the
325 * &pattern and applies &action to those. To avoid consuming too much
326 * CPU time or IO resources for the &action, "a is used.
328 * If @apply_interval_us is zero, &damon_attrs->aggr_interval is used instead.
330 * To do the work only when needed, schemes can be activated for specific
331 * system situations using &wmarks. If all schemes that registered to the
332 * monitoring context are inactive, DAMON stops monitoring either, and just
333 * repeatedly checks the watermarks.
335 * Before applying the &action to a memory region, &struct damon_operations
336 * implementation could check pages of the region and skip &action to respect
339 * After applying the &action to each region, &stat_count and &stat_sz is
340 * updated to reflect the number of regions and total size of regions that the
341 * &action is applied.
344 struct damos_access_pattern pattern;
345 enum damos_action action;
346 unsigned long apply_interval_us;
347 /* private: internal use only */
349 * number of sample intervals that should be passed before applying
352 unsigned long next_apply_sis;
354 struct damos_quota quota;
355 struct damos_watermarks wmarks;
356 struct list_head filters;
357 struct damos_stat stat;
358 struct list_head list;
362 * enum damon_ops_id - Identifier for each monitoring operations implementation
364 * @DAMON_OPS_VADDR: Monitoring operations for virtual address spaces
365 * @DAMON_OPS_FVADDR: Monitoring operations for only fixed ranges of virtual
367 * @DAMON_OPS_PADDR: Monitoring operations for the physical address space
368 * @NR_DAMON_OPS: Number of monitoring operations implementations
380 * struct damon_operations - Monitoring operations for given use cases.
382 * @id: Identifier of this operations set.
383 * @init: Initialize operations-related data structures.
384 * @update: Update operations-related data structures.
385 * @prepare_access_checks: Prepare next access check of target regions.
386 * @check_accesses: Check the accesses to target regions.
387 * @reset_aggregated: Reset aggregated accesses monitoring results.
388 * @get_scheme_score: Get the score of a region for a scheme.
389 * @apply_scheme: Apply a DAMON-based operation scheme.
390 * @target_valid: Determine if the target is valid.
391 * @cleanup: Clean up the context.
393 * DAMON can be extended for various address spaces and usages. For this,
394 * users should register the low level operations for their target address
395 * space and usecase via the &damon_ctx.ops. Then, the monitoring thread
396 * (&damon_ctx.kdamond) calls @init and @prepare_access_checks before starting
397 * the monitoring, @update after each &damon_attrs.ops_update_interval, and
398 * @check_accesses, @target_valid and @prepare_access_checks after each
399 * &damon_attrs.sample_interval. Finally, @reset_aggregated is called after
400 * each &damon_attrs.aggr_interval.
402 * Each &struct damon_operations instance having valid @id can be registered
403 * via damon_register_ops() and selected by damon_select_ops() later.
404 * @init should initialize operations-related data structures. For example,
405 * this could be used to construct proper monitoring target regions and link
406 * those to @damon_ctx.adaptive_targets.
407 * @update should update the operations-related data structures. For example,
408 * this could be used to update monitoring target regions for current status.
409 * @prepare_access_checks should manipulate the monitoring regions to be
410 * prepared for the next access check.
411 * @check_accesses should check the accesses to each region that made after the
412 * last preparation and update the number of observed accesses of each region.
413 * It should also return max number of observed accesses that made as a result
414 * of its update. The value will be used for regions adjustment threshold.
415 * @reset_aggregated should reset the access monitoring results that aggregated
416 * by @check_accesses.
417 * @get_scheme_score should return the priority score of a region for a scheme
418 * as an integer in [0, &DAMOS_MAX_SCORE].
419 * @apply_scheme is called from @kdamond when a region for user provided
420 * DAMON-based operation scheme is found. It should apply the scheme's action
421 * to the region and return bytes of the region that the action is successfully
423 * @target_valid should check whether the target is still valid for the
425 * @cleanup is called from @kdamond just before its termination.
427 struct damon_operations {
428 enum damon_ops_id id;
429 void (*init)(struct damon_ctx *context);
430 void (*update)(struct damon_ctx *context);
431 void (*prepare_access_checks)(struct damon_ctx *context);
432 unsigned int (*check_accesses)(struct damon_ctx *context);
433 void (*reset_aggregated)(struct damon_ctx *context);
434 int (*get_scheme_score)(struct damon_ctx *context,
435 struct damon_target *t, struct damon_region *r,
436 struct damos *scheme);
437 unsigned long (*apply_scheme)(struct damon_ctx *context,
438 struct damon_target *t, struct damon_region *r,
439 struct damos *scheme);
440 bool (*target_valid)(struct damon_target *t);
441 void (*cleanup)(struct damon_ctx *context);
445 * struct damon_callback - Monitoring events notification callbacks.
447 * @before_start: Called before starting the monitoring.
448 * @after_wmarks_check: Called after each schemes' watermarks check.
449 * @after_sampling: Called after each sampling.
450 * @after_aggregation: Called after each aggregation.
451 * @before_damos_apply: Called before applying DAMOS action.
452 * @before_terminate: Called before terminating the monitoring.
453 * @private: User private data.
455 * The monitoring thread (&damon_ctx.kdamond) calls @before_start and
456 * @before_terminate just before starting and finishing the monitoring,
457 * respectively. Therefore, those are good places for installing and cleaning
460 * The monitoring thread calls @after_wmarks_check after each DAMON-based
461 * operation schemes' watermarks check. If users need to make changes to the
462 * attributes of the monitoring context while it's deactivated due to the
463 * watermarks, this is the good place to do.
465 * The monitoring thread calls @after_sampling and @after_aggregation for each
466 * of the sampling intervals and aggregation intervals, respectively.
467 * Therefore, users can safely access the monitoring results without additional
468 * protection. For the reason, users are recommended to use these callback for
469 * the accesses to the results.
471 * If any callback returns non-zero, monitoring stops.
473 struct damon_callback {
476 int (*before_start)(struct damon_ctx *context);
477 int (*after_wmarks_check)(struct damon_ctx *context);
478 int (*after_sampling)(struct damon_ctx *context);
479 int (*after_aggregation)(struct damon_ctx *context);
480 int (*before_damos_apply)(struct damon_ctx *context,
481 struct damon_target *target,
482 struct damon_region *region,
483 struct damos *scheme);
484 void (*before_terminate)(struct damon_ctx *context);
488 * struct damon_attrs - Monitoring attributes for accuracy/overhead control.
490 * @sample_interval: The time between access samplings.
491 * @aggr_interval: The time between monitor results aggregations.
492 * @ops_update_interval: The time between monitoring operations updates.
493 * @min_nr_regions: The minimum number of adaptive monitoring
495 * @max_nr_regions: The maximum number of adaptive monitoring
498 * For each @sample_interval, DAMON checks whether each region is accessed or
499 * not during the last @sample_interval. If such access is found, DAMON
500 * aggregates the information by increasing &damon_region->nr_accesses for
501 * @aggr_interval time. For each @aggr_interval, the count is reset. DAMON
502 * also checks whether the target memory regions need update (e.g., by
503 * ``mmap()`` calls from the application, in case of virtual memory monitoring)
504 * and applies the changes for each @ops_update_interval. All time intervals
505 * are in micro-seconds. Please refer to &struct damon_operations and &struct
506 * damon_callback for more detail.
509 unsigned long sample_interval;
510 unsigned long aggr_interval;
511 unsigned long ops_update_interval;
512 unsigned long min_nr_regions;
513 unsigned long max_nr_regions;
517 * struct damon_ctx - Represents a context for each monitoring. This is the
518 * main interface that allows users to set the attributes and get the results
521 * @attrs: Monitoring attributes for accuracy/overhead control.
522 * @kdamond: Kernel thread who does the monitoring.
523 * @kdamond_lock: Mutex for the synchronizations with @kdamond.
525 * For each monitoring context, one kernel thread for the monitoring is
526 * created. The pointer to the thread is stored in @kdamond.
528 * Once started, the monitoring thread runs until explicitly required to be
529 * terminated or every monitoring target is invalid. The validity of the
530 * targets is checked via the &damon_operations.target_valid of @ops. The
531 * termination can also be explicitly requested by calling damon_stop().
532 * The thread sets @kdamond to NULL when it terminates. Therefore, users can
533 * know whether the monitoring is ongoing or terminated by reading @kdamond.
534 * Reads and writes to @kdamond from outside of the monitoring thread must
535 * be protected by @kdamond_lock.
537 * Note that the monitoring thread protects only @kdamond via @kdamond_lock.
538 * Accesses to other fields must be protected by themselves.
540 * @ops: Set of monitoring operations for given use cases.
541 * @callback: Set of callbacks for monitoring events notifications.
543 * @adaptive_targets: Head of monitoring targets (&damon_target) list.
544 * @schemes: Head of schemes (&damos) list.
547 struct damon_attrs attrs;
549 /* private: internal use only */
550 /* number of sample intervals that passed since this context started */
551 unsigned long passed_sample_intervals;
553 * number of sample intervals that should be passed before next
556 unsigned long next_aggregation_sis;
558 * number of sample intervals that should be passed before next ops
561 unsigned long next_ops_update_sis;
562 /* for waiting until the execution of the kdamond_fn is started */
563 struct completion kdamond_started;
566 struct task_struct *kdamond;
567 struct mutex kdamond_lock;
569 struct damon_operations ops;
570 struct damon_callback callback;
572 struct list_head adaptive_targets;
573 struct list_head schemes;
576 static inline struct damon_region *damon_next_region(struct damon_region *r)
578 return container_of(r->list.next, struct damon_region, list);
581 static inline struct damon_region *damon_prev_region(struct damon_region *r)
583 return container_of(r->list.prev, struct damon_region, list);
586 static inline struct damon_region *damon_last_region(struct damon_target *t)
588 return list_last_entry(&t->regions_list, struct damon_region, list);
591 static inline struct damon_region *damon_first_region(struct damon_target *t)
593 return list_first_entry(&t->regions_list, struct damon_region, list);
596 static inline unsigned long damon_sz_region(struct damon_region *r)
598 return r->ar.end - r->ar.start;
602 #define damon_for_each_region(r, t) \
603 list_for_each_entry(r, &t->regions_list, list)
605 #define damon_for_each_region_from(r, t) \
606 list_for_each_entry_from(r, &t->regions_list, list)
608 #define damon_for_each_region_safe(r, next, t) \
609 list_for_each_entry_safe(r, next, &t->regions_list, list)
611 #define damon_for_each_target(t, ctx) \
612 list_for_each_entry(t, &(ctx)->adaptive_targets, list)
614 #define damon_for_each_target_safe(t, next, ctx) \
615 list_for_each_entry_safe(t, next, &(ctx)->adaptive_targets, list)
617 #define damon_for_each_scheme(s, ctx) \
618 list_for_each_entry(s, &(ctx)->schemes, list)
620 #define damon_for_each_scheme_safe(s, next, ctx) \
621 list_for_each_entry_safe(s, next, &(ctx)->schemes, list)
623 #define damos_for_each_filter(f, scheme) \
624 list_for_each_entry(f, &(scheme)->filters, list)
626 #define damos_for_each_filter_safe(f, next, scheme) \
627 list_for_each_entry_safe(f, next, &(scheme)->filters, list)
631 struct damon_region *damon_new_region(unsigned long start, unsigned long end);
634 * Add a region between two other regions
636 static inline void damon_insert_region(struct damon_region *r,
637 struct damon_region *prev, struct damon_region *next,
638 struct damon_target *t)
640 __list_add(&r->list, &prev->list, &next->list);
644 void damon_add_region(struct damon_region *r, struct damon_target *t);
645 void damon_destroy_region(struct damon_region *r, struct damon_target *t);
646 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
647 unsigned int nr_ranges);
648 void damon_update_region_access_rate(struct damon_region *r, bool accessed,
649 struct damon_attrs *attrs);
651 struct damos_filter *damos_new_filter(enum damos_filter_type type,
653 void damos_add_filter(struct damos *s, struct damos_filter *f);
654 void damos_destroy_filter(struct damos_filter *f);
656 struct damos *damon_new_scheme(struct damos_access_pattern *pattern,
657 enum damos_action action,
658 unsigned long apply_interval_us,
659 struct damos_quota *quota,
660 struct damos_watermarks *wmarks);
661 void damon_add_scheme(struct damon_ctx *ctx, struct damos *s);
662 void damon_destroy_scheme(struct damos *s);
664 struct damon_target *damon_new_target(void);
665 void damon_add_target(struct damon_ctx *ctx, struct damon_target *t);
666 bool damon_targets_empty(struct damon_ctx *ctx);
667 void damon_free_target(struct damon_target *t);
668 void damon_destroy_target(struct damon_target *t);
669 unsigned int damon_nr_regions(struct damon_target *t);
671 struct damon_ctx *damon_new_ctx(void);
672 void damon_destroy_ctx(struct damon_ctx *ctx);
673 int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs);
674 void damon_set_schemes(struct damon_ctx *ctx,
675 struct damos **schemes, ssize_t nr_schemes);
676 int damon_nr_running_ctxs(void);
677 bool damon_is_registered_ops(enum damon_ops_id id);
678 int damon_register_ops(struct damon_operations *ops);
679 int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id);
681 static inline bool damon_target_has_pid(const struct damon_ctx *ctx)
683 return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR;
686 static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs)
688 /* {aggr,sample}_interval are unsigned long, hence could overflow */
689 return min(attrs->aggr_interval / attrs->sample_interval,
690 (unsigned long)UINT_MAX);
694 int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive);
695 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
697 int damon_set_region_biggest_system_ram_default(struct damon_target *t,
698 unsigned long *start, unsigned long *end);
700 #endif /* CONFIG_DAMON */
702 #endif /* _DAMON_H */