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2224d848 SP |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* | |
3 | * DAMON api | |
4 | * | |
6ad59a38 | 5 | * Author: SeongJae Park <sj@kernel.org> |
2224d848 SP |
6 | */ |
7 | ||
8 | #ifndef _DAMON_H_ | |
9 | #define _DAMON_H_ | |
10 | ||
98def236 | 11 | #include <linux/memcontrol.h> |
2224d848 SP |
12 | #include <linux/mutex.h> |
13 | #include <linux/time64.h> | |
14 | #include <linux/types.h> | |
9b2a38d6 | 15 | #include <linux/random.h> |
2224d848 | 16 | |
b9a6ac4e SP |
17 | /* Minimal region size. Every damon_region is aligned by this. */ |
18 | #define DAMON_MIN_REGION PAGE_SIZE | |
38683e00 SP |
19 | /* Max priority score for DAMON-based operation schemes */ |
20 | #define DAMOS_MAX_SCORE (99) | |
b9a6ac4e | 21 | |
9b2a38d6 | 22 | /* Get a random number in [l, r) */ |
234d6873 XH |
23 | static inline unsigned long damon_rand(unsigned long l, unsigned long r) |
24 | { | |
8032bf12 | 25 | return l + get_random_u32_below(r - l); |
234d6873 | 26 | } |
9b2a38d6 | 27 | |
f23b8eee SP |
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. | |
ace30fb2 SP |
43 | * @nr_accesses_bp: @nr_accesses in basis point (0.01%) that updated for |
44 | * each sampling interval. | |
f23b8eee | 45 | * @list: List head for siblings. |
fda504fa SP |
46 | * @age: Age of this region. |
47 | * | |
d896073f SP |
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 | |
78fbfb15 SP |
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(). | |
d896073f | 53 | * |
80333828 | 54 | * @nr_accesses_bp is another representation of @nr_accesses in basis point |
ace30fb2 SP |
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. | |
80333828 | 60 | * |
fda504fa SP |
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. | |
f23b8eee SP |
65 | */ |
66 | struct damon_region { | |
67 | struct damon_addr_range ar; | |
68 | unsigned long sampling_addr; | |
69 | unsigned int nr_accesses; | |
80333828 | 70 | unsigned int nr_accesses_bp; |
f23b8eee | 71 | struct list_head list; |
fda504fa SP |
72 | |
73 | unsigned int age; | |
74 | /* private: Internal value for age calculation. */ | |
75 | unsigned int last_nr_accesses; | |
f23b8eee SP |
76 | }; |
77 | ||
78 | /** | |
79 | * struct damon_target - Represents a monitoring target. | |
1971bd63 | 80 | * @pid: The PID of the virtual address space to monitor. |
b9a6ac4e | 81 | * @nr_regions: Number of monitoring target regions of this target. |
f23b8eee SP |
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 | |
f7d911c3 SP |
87 | * @pid should be set for appropriate &struct damon_operations including the |
88 | * virtual address spaces monitoring operations. | |
f23b8eee SP |
89 | */ |
90 | struct damon_target { | |
1971bd63 | 91 | struct pid *pid; |
b9a6ac4e | 92 | unsigned int nr_regions; |
f23b8eee SP |
93 | struct list_head regions_list; |
94 | struct list_head list; | |
95 | }; | |
96 | ||
1f366e42 SP |
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. | |
8cdcc532 | 106 | * @DAMOS_LRU_PRIO: Prioritize the region on its LRU lists. |
99cdc2cd | 107 | * @DAMOS_LRU_DEPRIO: Deprioritize the region on its LRU lists. |
2f0b548c | 108 | * @DAMOS_STAT: Do nothing but count the stat. |
5257f36e | 109 | * @NR_DAMOS_ACTIONS: Total number of DAMOS actions |
fb6f026b SP |
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. | |
1f366e42 SP |
116 | */ |
117 | enum damos_action { | |
118 | DAMOS_WILLNEED, | |
119 | DAMOS_COLD, | |
120 | DAMOS_PAGEOUT, | |
121 | DAMOS_HUGEPAGE, | |
122 | DAMOS_NOHUGEPAGE, | |
8cdcc532 | 123 | DAMOS_LRU_PRIO, |
99cdc2cd | 124 | DAMOS_LRU_DEPRIO, |
2f0b548c | 125 | DAMOS_STAT, /* Do nothing but only record the stat */ |
5257f36e | 126 | NR_DAMOS_ACTIONS, |
1f366e42 SP |
127 | }; |
128 | ||
106e26fc SP |
129 | /** |
130 | * struct damos_quota_goal - DAMOS scheme quota auto-tuning goal. | |
131 | * @get_score: Function for getting current score of the goal. | |
132 | * @get_score_arg: Parameter for @get_score | |
133 | * | |
134 | * Data structure for getting the current score of the quota tuning goal. | |
135 | * Calling @get_score with @get_score_arg as the parameter should return the | |
136 | * current score. Then the score is entered to DAMON's internal feedback loop | |
137 | * mechanism to get the auto-tuned quota. The goal of the tuning is getting | |
138 | * the feedback score value of 10,000. | |
139 | */ | |
140 | struct damos_quota_goal { | |
141 | unsigned long (*get_score)(void *arg); | |
142 | void *get_score_arg; | |
143 | }; | |
144 | ||
2b8a248d SP |
145 | /** |
146 | * struct damos_quota - Controls the aggressiveness of the given scheme. | |
4d791a0a | 147 | * @reset_interval: Charge reset interval in milliseconds. |
1cd24303 | 148 | * @ms: Maximum milliseconds that the scheme can use. |
2b8a248d | 149 | * @sz: Maximum bytes of memory that the action can be applied. |
106e26fc | 150 | * @goal: Quota auto-tuning goal. |
4d791a0a | 151 | * @esz: Effective size quota in bytes. |
2b8a248d | 152 | * |
38683e00 SP |
153 | * @weight_sz: Weight of the region's size for prioritization. |
154 | * @weight_nr_accesses: Weight of the region's nr_accesses for prioritization. | |
155 | * @weight_age: Weight of the region's age for prioritization. | |
156 | * | |
2b8a248d | 157 | * To avoid consuming too much CPU time or IO resources for applying the |
1cd24303 SP |
158 | * &struct damos->action to large memory, DAMON allows users to set time and/or |
159 | * size quotas. The quotas can be set by writing non-zero values to &ms and | |
160 | * &sz, respectively. If the time quota is set, DAMON tries to use only up to | |
161 | * &ms milliseconds within &reset_interval for applying the action. If the | |
162 | * size quota is set, DAMON tries to apply the action only up to &sz bytes | |
163 | * within &reset_interval. | |
164 | * | |
165 | * Internally, the time quota is transformed to a size quota using estimated | |
166 | * throughput of the scheme's action. DAMON then compares it against &sz and | |
167 | * uses smaller one as the effective quota. | |
38683e00 | 168 | * |
106e26fc SP |
169 | * If ->get_score field of @goal is set, DAMON calculates yet another size |
170 | * quota based on the goal using its internal feedback loop algorithm, for | |
171 | * every @reset_interval. Then, if the new size quota is smaller than the | |
172 | * effective quota, it uses the new size quota as the effective quota. | |
78f2f603 SP |
173 | * |
174 | * The resulting effective size quota in bytes is set to @esz. | |
4d791a0a SP |
175 | * |
176 | * For selecting regions within the quota, DAMON prioritizes current scheme's | |
177 | * target memory regions using the &struct damon_operations->get_scheme_score. | |
178 | * You could customize the prioritization logic by setting &weight_sz, | |
179 | * &weight_nr_accesses, and &weight_age, because monitoring operations are | |
180 | * encouraged to respect those. | |
2b8a248d SP |
181 | */ |
182 | struct damos_quota { | |
4d791a0a | 183 | unsigned long reset_interval; |
1cd24303 | 184 | unsigned long ms; |
2b8a248d | 185 | unsigned long sz; |
106e26fc | 186 | struct damos_quota_goal goal; |
4d791a0a | 187 | unsigned long esz; |
2b8a248d | 188 | |
38683e00 SP |
189 | unsigned int weight_sz; |
190 | unsigned int weight_nr_accesses; | |
191 | unsigned int weight_age; | |
192 | ||
1cd24303 SP |
193 | /* private: */ |
194 | /* For throughput estimation */ | |
195 | unsigned long total_charged_sz; | |
196 | unsigned long total_charged_ns; | |
197 | ||
1cd24303 | 198 | /* For charging the quota */ |
2b8a248d SP |
199 | unsigned long charged_sz; |
200 | unsigned long charged_from; | |
50585192 SP |
201 | struct damon_target *charge_target_from; |
202 | unsigned long charge_addr_from; | |
38683e00 SP |
203 | |
204 | /* For prioritization */ | |
205 | unsigned long histogram[DAMOS_MAX_SCORE + 1]; | |
206 | unsigned int min_score; | |
9294a037 SP |
207 | |
208 | /* For feedback loop */ | |
209 | unsigned long esz_bp; | |
2b8a248d SP |
210 | }; |
211 | ||
ee801b7d SP |
212 | /** |
213 | * enum damos_wmark_metric - Represents the watermark metric. | |
214 | * | |
215 | * @DAMOS_WMARK_NONE: Ignore the watermarks of the given scheme. | |
216 | * @DAMOS_WMARK_FREE_MEM_RATE: Free memory rate of the system in [0,1000]. | |
5257f36e | 217 | * @NR_DAMOS_WMARK_METRICS: Total number of DAMOS watermark metrics |
ee801b7d SP |
218 | */ |
219 | enum damos_wmark_metric { | |
220 | DAMOS_WMARK_NONE, | |
221 | DAMOS_WMARK_FREE_MEM_RATE, | |
5257f36e | 222 | NR_DAMOS_WMARK_METRICS, |
ee801b7d SP |
223 | }; |
224 | ||
225 | /** | |
226 | * struct damos_watermarks - Controls when a given scheme should be activated. | |
227 | * @metric: Metric for the watermarks. | |
228 | * @interval: Watermarks check time interval in microseconds. | |
229 | * @high: High watermark. | |
230 | * @mid: Middle watermark. | |
231 | * @low: Low watermark. | |
232 | * | |
233 | * If &metric is &DAMOS_WMARK_NONE, the scheme is always active. Being active | |
234 | * means DAMON does monitoring and applying the action of the scheme to | |
235 | * appropriate memory regions. Else, DAMON checks &metric of the system for at | |
236 | * least every &interval microseconds and works as below. | |
237 | * | |
238 | * If &metric is higher than &high, the scheme is inactivated. If &metric is | |
239 | * between &mid and &low, the scheme is activated. If &metric is lower than | |
240 | * &low, the scheme is inactivated. | |
241 | */ | |
242 | struct damos_watermarks { | |
243 | enum damos_wmark_metric metric; | |
244 | unsigned long interval; | |
245 | unsigned long high; | |
246 | unsigned long mid; | |
247 | unsigned long low; | |
248 | ||
249 | /* private: */ | |
250 | bool activated; | |
251 | }; | |
252 | ||
0e92c2ee SP |
253 | /** |
254 | * struct damos_stat - Statistics on a given scheme. | |
255 | * @nr_tried: Total number of regions that the scheme is tried to be applied. | |
256 | * @sz_tried: Total size of regions that the scheme is tried to be applied. | |
257 | * @nr_applied: Total number of regions that the scheme is applied. | |
258 | * @sz_applied: Total size of regions that the scheme is applied. | |
6268eac3 | 259 | * @qt_exceeds: Total number of times the quota of the scheme has exceeded. |
0e92c2ee SP |
260 | */ |
261 | struct damos_stat { | |
262 | unsigned long nr_tried; | |
263 | unsigned long sz_tried; | |
264 | unsigned long nr_applied; | |
265 | unsigned long sz_applied; | |
6268eac3 | 266 | unsigned long qt_exceeds; |
0e92c2ee SP |
267 | }; |
268 | ||
98def236 SP |
269 | /** |
270 | * enum damos_filter_type - Type of memory for &struct damos_filter | |
271 | * @DAMOS_FILTER_TYPE_ANON: Anonymous pages. | |
272 | * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages. | |
ab9bda00 | 273 | * @DAMOS_FILTER_TYPE_ADDR: Address range. |
17e7c724 | 274 | * @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target. |
98def236 | 275 | * @NR_DAMOS_FILTER_TYPES: Number of filter types. |
55901e89 | 276 | * |
ab9bda00 SP |
277 | * The anon pages type and memcg type filters are handled by underlying |
278 | * &struct damon_operations as a part of scheme action trying, and therefore | |
279 | * accounted as 'tried'. In contrast, other types are handled by core layer | |
280 | * before trying of the action and therefore not accounted as 'tried'. | |
281 | * | |
282 | * The support of the filters that handled by &struct damon_operations depend | |
283 | * on the running &struct damon_operations. | |
284 | * &enum DAMON_OPS_PADDR supports both anon pages type and memcg type filters, | |
285 | * while &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR don't support any of | |
286 | * the two types. | |
98def236 SP |
287 | */ |
288 | enum damos_filter_type { | |
289 | DAMOS_FILTER_TYPE_ANON, | |
290 | DAMOS_FILTER_TYPE_MEMCG, | |
ab9bda00 | 291 | DAMOS_FILTER_TYPE_ADDR, |
17e7c724 | 292 | DAMOS_FILTER_TYPE_TARGET, |
98def236 SP |
293 | NR_DAMOS_FILTER_TYPES, |
294 | }; | |
295 | ||
296 | /** | |
297 | * struct damos_filter - DAMOS action target memory filter. | |
298 | * @type: Type of the page. | |
299 | * @matching: If the matching page should filtered out or in. | |
300 | * @memcg_id: Memcg id of the question if @type is DAMOS_FILTER_MEMCG. | |
ab9bda00 | 301 | * @addr_range: Address range if @type is DAMOS_FILTER_TYPE_ADDR. |
17e7c724 SP |
302 | * @target_idx: Index of the &struct damon_target of |
303 | * &damon_ctx->adaptive_targets if @type is | |
304 | * DAMOS_FILTER_TYPE_TARGET. | |
98def236 SP |
305 | * @list: List head for siblings. |
306 | * | |
307 | * Before applying the &damos->action to a memory region, DAMOS checks if each | |
308 | * page of the region matches to this and avoid applying the action if so. | |
ab9bda00 SP |
309 | * Support of each filter type depends on the running &struct damon_operations |
310 | * and the type. Refer to &enum damos_filter_type for more detai. | |
98def236 SP |
311 | */ |
312 | struct damos_filter { | |
313 | enum damos_filter_type type; | |
314 | bool matching; | |
315 | union { | |
316 | unsigned short memcg_id; | |
ab9bda00 | 317 | struct damon_addr_range addr_range; |
17e7c724 | 318 | int target_idx; |
98def236 SP |
319 | }; |
320 | struct list_head list; | |
321 | }; | |
322 | ||
1f366e42 | 323 | /** |
f5a79d7c | 324 | * struct damos_access_pattern - Target access pattern of the given scheme. |
1f366e42 SP |
325 | * @min_sz_region: Minimum size of target regions. |
326 | * @max_sz_region: Maximum size of target regions. | |
327 | * @min_nr_accesses: Minimum ``->nr_accesses`` of target regions. | |
328 | * @max_nr_accesses: Maximum ``->nr_accesses`` of target regions. | |
329 | * @min_age_region: Minimum age of target regions. | |
330 | * @max_age_region: Maximum age of target regions. | |
f5a79d7c YD |
331 | */ |
332 | struct damos_access_pattern { | |
333 | unsigned long min_sz_region; | |
334 | unsigned long max_sz_region; | |
335 | unsigned int min_nr_accesses; | |
336 | unsigned int max_nr_accesses; | |
337 | unsigned int min_age_region; | |
338 | unsigned int max_age_region; | |
339 | }; | |
340 | ||
341 | /** | |
342 | * struct damos - Represents a Data Access Monitoring-based Operation Scheme. | |
343 | * @pattern: Access pattern of target regions. | |
1f366e42 | 344 | * @action: &damo_action to be applied to the target regions. |
42f994b7 | 345 | * @apply_interval_us: The time between applying the @action. |
2b8a248d | 346 | * @quota: Control the aggressiveness of this scheme. |
ee801b7d | 347 | * @wmarks: Watermarks for automated (in)activation of this scheme. |
98def236 | 348 | * @filters: Additional set of &struct damos_filter for &action. |
0e92c2ee | 349 | * @stat: Statistics of this scheme. |
1f366e42 SP |
350 | * @list: List head for siblings. |
351 | * | |
42f994b7 | 352 | * For each @apply_interval_us, DAMON finds regions which fit in the |
f5a79d7c YD |
353 | * &pattern and applies &action to those. To avoid consuming too much |
354 | * CPU time or IO resources for the &action, "a is used. | |
2b8a248d | 355 | * |
42f994b7 SP |
356 | * If @apply_interval_us is zero, &damon_attrs->aggr_interval is used instead. |
357 | * | |
ee801b7d SP |
358 | * To do the work only when needed, schemes can be activated for specific |
359 | * system situations using &wmarks. If all schemes that registered to the | |
360 | * monitoring context are inactive, DAMON stops monitoring either, and just | |
361 | * repeatedly checks the watermarks. | |
362 | * | |
98def236 SP |
363 | * Before applying the &action to a memory region, &struct damon_operations |
364 | * implementation could check pages of the region and skip &action to respect | |
365 | * &filters | |
366 | * | |
2b8a248d SP |
367 | * After applying the &action to each region, &stat_count and &stat_sz is |
368 | * updated to reflect the number of regions and total size of regions that the | |
369 | * &action is applied. | |
1f366e42 SP |
370 | */ |
371 | struct damos { | |
f5a79d7c | 372 | struct damos_access_pattern pattern; |
1f366e42 | 373 | enum damos_action action; |
42f994b7 SP |
374 | unsigned long apply_interval_us; |
375 | /* private: internal use only */ | |
376 | /* | |
377 | * number of sample intervals that should be passed before applying | |
378 | * @action | |
379 | */ | |
380 | unsigned long next_apply_sis; | |
381 | /* public: */ | |
2b8a248d | 382 | struct damos_quota quota; |
ee801b7d | 383 | struct damos_watermarks wmarks; |
98def236 | 384 | struct list_head filters; |
0e92c2ee | 385 | struct damos_stat stat; |
1f366e42 SP |
386 | struct list_head list; |
387 | }; | |
388 | ||
9f7b053a SP |
389 | /** |
390 | * enum damon_ops_id - Identifier for each monitoring operations implementation | |
391 | * | |
392 | * @DAMON_OPS_VADDR: Monitoring operations for virtual address spaces | |
de6d0154 SP |
393 | * @DAMON_OPS_FVADDR: Monitoring operations for only fixed ranges of virtual |
394 | * address spaces | |
9f7b053a | 395 | * @DAMON_OPS_PADDR: Monitoring operations for the physical address space |
d4a157f5 | 396 | * @NR_DAMON_OPS: Number of monitoring operations implementations |
9f7b053a SP |
397 | */ |
398 | enum damon_ops_id { | |
399 | DAMON_OPS_VADDR, | |
de6d0154 | 400 | DAMON_OPS_FVADDR, |
9f7b053a SP |
401 | DAMON_OPS_PADDR, |
402 | NR_DAMON_OPS, | |
403 | }; | |
404 | ||
2224d848 SP |
405 | struct damon_ctx; |
406 | ||
407 | /** | |
f7d911c3 | 408 | * struct damon_operations - Monitoring operations for given use cases. |
2224d848 | 409 | * |
9f7b053a | 410 | * @id: Identifier of this operations set. |
f7d911c3 SP |
411 | * @init: Initialize operations-related data structures. |
412 | * @update: Update operations-related data structures. | |
2224d848 SP |
413 | * @prepare_access_checks: Prepare next access check of target regions. |
414 | * @check_accesses: Check the accesses to target regions. | |
415 | * @reset_aggregated: Reset aggregated accesses monitoring results. | |
38683e00 | 416 | * @get_scheme_score: Get the score of a region for a scheme. |
1f366e42 | 417 | * @apply_scheme: Apply a DAMON-based operation scheme. |
2224d848 SP |
418 | * @target_valid: Determine if the target is valid. |
419 | * @cleanup: Clean up the context. | |
420 | * | |
421 | * DAMON can be extended for various address spaces and usages. For this, | |
f7d911c3 SP |
422 | * users should register the low level operations for their target address |
423 | * space and usecase via the &damon_ctx.ops. Then, the monitoring thread | |
2224d848 | 424 | * (&damon_ctx.kdamond) calls @init and @prepare_access_checks before starting |
6b3f013b | 425 | * the monitoring, @update after each &damon_attrs.ops_update_interval, and |
2224d848 | 426 | * @check_accesses, @target_valid and @prepare_access_checks after each |
6b3f013b SP |
427 | * &damon_attrs.sample_interval. Finally, @reset_aggregated is called after |
428 | * each &damon_attrs.aggr_interval. | |
2224d848 | 429 | * |
9f7b053a SP |
430 | * Each &struct damon_operations instance having valid @id can be registered |
431 | * via damon_register_ops() and selected by damon_select_ops() later. | |
f7d911c3 | 432 | * @init should initialize operations-related data structures. For example, |
2224d848 | 433 | * this could be used to construct proper monitoring target regions and link |
f23b8eee | 434 | * those to @damon_ctx.adaptive_targets. |
f7d911c3 | 435 | * @update should update the operations-related data structures. For example, |
2224d848 SP |
436 | * this could be used to update monitoring target regions for current status. |
437 | * @prepare_access_checks should manipulate the monitoring regions to be | |
438 | * prepared for the next access check. | |
439 | * @check_accesses should check the accesses to each region that made after the | |
440 | * last preparation and update the number of observed accesses of each region. | |
b9a6ac4e SP |
441 | * It should also return max number of observed accesses that made as a result |
442 | * of its update. The value will be used for regions adjustment threshold. | |
2224d848 SP |
443 | * @reset_aggregated should reset the access monitoring results that aggregated |
444 | * by @check_accesses. | |
38683e00 SP |
445 | * @get_scheme_score should return the priority score of a region for a scheme |
446 | * as an integer in [0, &DAMOS_MAX_SCORE]. | |
1f366e42 SP |
447 | * @apply_scheme is called from @kdamond when a region for user provided |
448 | * DAMON-based operation scheme is found. It should apply the scheme's action | |
0e92c2ee SP |
449 | * to the region and return bytes of the region that the action is successfully |
450 | * applied. | |
2224d848 SP |
451 | * @target_valid should check whether the target is still valid for the |
452 | * monitoring. | |
453 | * @cleanup is called from @kdamond just before its termination. | |
454 | */ | |
f7d911c3 | 455 | struct damon_operations { |
9f7b053a | 456 | enum damon_ops_id id; |
2224d848 SP |
457 | void (*init)(struct damon_ctx *context); |
458 | void (*update)(struct damon_ctx *context); | |
459 | void (*prepare_access_checks)(struct damon_ctx *context); | |
b9a6ac4e | 460 | unsigned int (*check_accesses)(struct damon_ctx *context); |
2224d848 | 461 | void (*reset_aggregated)(struct damon_ctx *context); |
38683e00 SP |
462 | int (*get_scheme_score)(struct damon_ctx *context, |
463 | struct damon_target *t, struct damon_region *r, | |
464 | struct damos *scheme); | |
0e92c2ee SP |
465 | unsigned long (*apply_scheme)(struct damon_ctx *context, |
466 | struct damon_target *t, struct damon_region *r, | |
467 | struct damos *scheme); | |
16bc1b0f | 468 | bool (*target_valid)(struct damon_target *t); |
2224d848 SP |
469 | void (*cleanup)(struct damon_ctx *context); |
470 | }; | |
471 | ||
d2f272b3 SP |
472 | /** |
473 | * struct damon_callback - Monitoring events notification callbacks. | |
2224d848 SP |
474 | * |
475 | * @before_start: Called before starting the monitoring. | |
6e74d2bf | 476 | * @after_wmarks_check: Called after each schemes' watermarks check. |
2224d848 SP |
477 | * @after_sampling: Called after each sampling. |
478 | * @after_aggregation: Called after each aggregation. | |
44467bbb | 479 | * @before_damos_apply: Called before applying DAMOS action. |
2224d848 SP |
480 | * @before_terminate: Called before terminating the monitoring. |
481 | * @private: User private data. | |
482 | * | |
483 | * The monitoring thread (&damon_ctx.kdamond) calls @before_start and | |
484 | * @before_terminate just before starting and finishing the monitoring, | |
485 | * respectively. Therefore, those are good places for installing and cleaning | |
486 | * @private. | |
487 | * | |
6e74d2bf SP |
488 | * The monitoring thread calls @after_wmarks_check after each DAMON-based |
489 | * operation schemes' watermarks check. If users need to make changes to the | |
490 | * attributes of the monitoring context while it's deactivated due to the | |
491 | * watermarks, this is the good place to do. | |
492 | * | |
2224d848 SP |
493 | * The monitoring thread calls @after_sampling and @after_aggregation for each |
494 | * of the sampling intervals and aggregation intervals, respectively. | |
495 | * Therefore, users can safely access the monitoring results without additional | |
496 | * protection. For the reason, users are recommended to use these callback for | |
497 | * the accesses to the results. | |
498 | * | |
499 | * If any callback returns non-zero, monitoring stops. | |
500 | */ | |
501 | struct damon_callback { | |
502 | void *private; | |
503 | ||
504 | int (*before_start)(struct damon_ctx *context); | |
6e74d2bf | 505 | int (*after_wmarks_check)(struct damon_ctx *context); |
2224d848 SP |
506 | int (*after_sampling)(struct damon_ctx *context); |
507 | int (*after_aggregation)(struct damon_ctx *context); | |
44467bbb SP |
508 | int (*before_damos_apply)(struct damon_ctx *context, |
509 | struct damon_target *target, | |
510 | struct damon_region *region, | |
511 | struct damos *scheme); | |
658f9ae7 | 512 | void (*before_terminate)(struct damon_ctx *context); |
2224d848 SP |
513 | }; |
514 | ||
515 | /** | |
cbeaa77b | 516 | * struct damon_attrs - Monitoring attributes for accuracy/overhead control. |
2224d848 SP |
517 | * |
518 | * @sample_interval: The time between access samplings. | |
519 | * @aggr_interval: The time between monitor results aggregations. | |
f7d911c3 | 520 | * @ops_update_interval: The time between monitoring operations updates. |
cbeaa77b SP |
521 | * @min_nr_regions: The minimum number of adaptive monitoring |
522 | * regions. | |
523 | * @max_nr_regions: The maximum number of adaptive monitoring | |
524 | * regions. | |
2224d848 SP |
525 | * |
526 | * For each @sample_interval, DAMON checks whether each region is accessed or | |
d896073f SP |
527 | * not during the last @sample_interval. If such access is found, DAMON |
528 | * aggregates the information by increasing &damon_region->nr_accesses for | |
529 | * @aggr_interval time. For each @aggr_interval, the count is reset. DAMON | |
530 | * also checks whether the target memory regions need update (e.g., by | |
531 | * ``mmap()`` calls from the application, in case of virtual memory monitoring) | |
532 | * and applies the changes for each @ops_update_interval. All time intervals | |
533 | * are in micro-seconds. Please refer to &struct damon_operations and &struct | |
534 | * damon_callback for more detail. | |
cbeaa77b SP |
535 | */ |
536 | struct damon_attrs { | |
537 | unsigned long sample_interval; | |
538 | unsigned long aggr_interval; | |
539 | unsigned long ops_update_interval; | |
540 | unsigned long min_nr_regions; | |
541 | unsigned long max_nr_regions; | |
542 | }; | |
543 | ||
544 | /** | |
545 | * struct damon_ctx - Represents a context for each monitoring. This is the | |
546 | * main interface that allows users to set the attributes and get the results | |
547 | * of the monitoring. | |
2224d848 | 548 | * |
cbeaa77b | 549 | * @attrs: Monitoring attributes for accuracy/overhead control. |
2224d848 | 550 | * @kdamond: Kernel thread who does the monitoring. |
2224d848 SP |
551 | * @kdamond_lock: Mutex for the synchronizations with @kdamond. |
552 | * | |
553 | * For each monitoring context, one kernel thread for the monitoring is | |
554 | * created. The pointer to the thread is stored in @kdamond. | |
555 | * | |
556 | * Once started, the monitoring thread runs until explicitly required to be | |
557 | * terminated or every monitoring target is invalid. The validity of the | |
f7d911c3 | 558 | * targets is checked via the &damon_operations.target_valid of @ops. The |
bcc728eb CZ |
559 | * termination can also be explicitly requested by calling damon_stop(). |
560 | * The thread sets @kdamond to NULL when it terminates. Therefore, users can | |
561 | * know whether the monitoring is ongoing or terminated by reading @kdamond. | |
562 | * Reads and writes to @kdamond from outside of the monitoring thread must | |
563 | * be protected by @kdamond_lock. | |
564 | * | |
565 | * Note that the monitoring thread protects only @kdamond via @kdamond_lock. | |
566 | * Accesses to other fields must be protected by themselves. | |
2224d848 | 567 | * |
f7d911c3 | 568 | * @ops: Set of monitoring operations for given use cases. |
2224d848 SP |
569 | * @callback: Set of callbacks for monitoring events notifications. |
570 | * | |
b9a6ac4e | 571 | * @adaptive_targets: Head of monitoring targets (&damon_target) list. |
1f366e42 | 572 | * @schemes: Head of schemes (&damos) list. |
2224d848 SP |
573 | */ |
574 | struct damon_ctx { | |
cbeaa77b | 575 | struct damon_attrs attrs; |
2224d848 SP |
576 | |
577 | /* private: internal use only */ | |
4472edf6 SP |
578 | /* number of sample intervals that passed since this context started */ |
579 | unsigned long passed_sample_intervals; | |
580 | /* | |
581 | * number of sample intervals that should be passed before next | |
582 | * aggregation | |
583 | */ | |
584 | unsigned long next_aggregation_sis; | |
585 | /* | |
586 | * number of sample intervals that should be passed before next ops | |
587 | * update | |
588 | */ | |
589 | unsigned long next_ops_update_sis; | |
6376a824 SP |
590 | /* for waiting until the execution of the kdamond_fn is started */ |
591 | struct completion kdamond_started; | |
2224d848 SP |
592 | |
593 | /* public: */ | |
594 | struct task_struct *kdamond; | |
2224d848 SP |
595 | struct mutex kdamond_lock; |
596 | ||
f7d911c3 | 597 | struct damon_operations ops; |
2224d848 SP |
598 | struct damon_callback callback; |
599 | ||
b9a6ac4e | 600 | struct list_head adaptive_targets; |
1f366e42 | 601 | struct list_head schemes; |
2224d848 SP |
602 | }; |
603 | ||
88f86dcf SP |
604 | static inline struct damon_region *damon_next_region(struct damon_region *r) |
605 | { | |
606 | return container_of(r->list.next, struct damon_region, list); | |
607 | } | |
f23b8eee | 608 | |
88f86dcf SP |
609 | static inline struct damon_region *damon_prev_region(struct damon_region *r) |
610 | { | |
611 | return container_of(r->list.prev, struct damon_region, list); | |
612 | } | |
f23b8eee | 613 | |
88f86dcf SP |
614 | static inline struct damon_region *damon_last_region(struct damon_target *t) |
615 | { | |
616 | return list_last_entry(&t->regions_list, struct damon_region, list); | |
617 | } | |
50585192 | 618 | |
36001cba KX |
619 | static inline struct damon_region *damon_first_region(struct damon_target *t) |
620 | { | |
621 | return list_first_entry(&t->regions_list, struct damon_region, list); | |
622 | } | |
623 | ||
652e0446 XH |
624 | static inline unsigned long damon_sz_region(struct damon_region *r) |
625 | { | |
626 | return r->ar.end - r->ar.start; | |
627 | } | |
628 | ||
629 | ||
f23b8eee SP |
630 | #define damon_for_each_region(r, t) \ |
631 | list_for_each_entry(r, &t->regions_list, list) | |
632 | ||
36001cba KX |
633 | #define damon_for_each_region_from(r, t) \ |
634 | list_for_each_entry_from(r, &t->regions_list, list) | |
635 | ||
f23b8eee SP |
636 | #define damon_for_each_region_safe(r, next, t) \ |
637 | list_for_each_entry_safe(r, next, &t->regions_list, list) | |
638 | ||
639 | #define damon_for_each_target(t, ctx) \ | |
b9a6ac4e | 640 | list_for_each_entry(t, &(ctx)->adaptive_targets, list) |
f23b8eee SP |
641 | |
642 | #define damon_for_each_target_safe(t, next, ctx) \ | |
b9a6ac4e | 643 | list_for_each_entry_safe(t, next, &(ctx)->adaptive_targets, list) |
f23b8eee | 644 | |
1f366e42 SP |
645 | #define damon_for_each_scheme(s, ctx) \ |
646 | list_for_each_entry(s, &(ctx)->schemes, list) | |
647 | ||
648 | #define damon_for_each_scheme_safe(s, next, ctx) \ | |
649 | list_for_each_entry_safe(s, next, &(ctx)->schemes, list) | |
650 | ||
98def236 SP |
651 | #define damos_for_each_filter(f, scheme) \ |
652 | list_for_each_entry(f, &(scheme)->filters, list) | |
653 | ||
654 | #define damos_for_each_filter_safe(f, next, scheme) \ | |
655 | list_for_each_entry_safe(f, next, &(scheme)->filters, list) | |
656 | ||
2224d848 SP |
657 | #ifdef CONFIG_DAMON |
658 | ||
f23b8eee | 659 | struct damon_region *damon_new_region(unsigned long start, unsigned long end); |
2cd4b8e1 GJ |
660 | |
661 | /* | |
662 | * Add a region between two other regions | |
663 | */ | |
664 | static inline void damon_insert_region(struct damon_region *r, | |
b9a6ac4e | 665 | struct damon_region *prev, struct damon_region *next, |
2cd4b8e1 GJ |
666 | struct damon_target *t) |
667 | { | |
668 | __list_add(&r->list, &prev->list, &next->list); | |
669 | t->nr_regions++; | |
670 | } | |
671 | ||
f23b8eee | 672 | void damon_add_region(struct damon_region *r, struct damon_target *t); |
b9a6ac4e | 673 | void damon_destroy_region(struct damon_region *r, struct damon_target *t); |
d0723bc0 SP |
674 | int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, |
675 | unsigned int nr_ranges); | |
ace30fb2 SP |
676 | void damon_update_region_access_rate(struct damon_region *r, bool accessed, |
677 | struct damon_attrs *attrs); | |
f23b8eee | 678 | |
98def236 SP |
679 | struct damos_filter *damos_new_filter(enum damos_filter_type type, |
680 | bool matching); | |
681 | void damos_add_filter(struct damos *s, struct damos_filter *f); | |
682 | void damos_destroy_filter(struct damos_filter *f); | |
683 | ||
f5a79d7c | 684 | struct damos *damon_new_scheme(struct damos_access_pattern *pattern, |
42f994b7 SP |
685 | enum damos_action action, |
686 | unsigned long apply_interval_us, | |
687 | struct damos_quota *quota, | |
f5a79d7c | 688 | struct damos_watermarks *wmarks); |
1f366e42 SP |
689 | void damon_add_scheme(struct damon_ctx *ctx, struct damos *s); |
690 | void damon_destroy_scheme(struct damos *s); | |
691 | ||
1971bd63 | 692 | struct damon_target *damon_new_target(void); |
f23b8eee | 693 | void damon_add_target(struct damon_ctx *ctx, struct damon_target *t); |
b5ca3e83 | 694 | bool damon_targets_empty(struct damon_ctx *ctx); |
f23b8eee SP |
695 | void damon_free_target(struct damon_target *t); |
696 | void damon_destroy_target(struct damon_target *t); | |
b9a6ac4e | 697 | unsigned int damon_nr_regions(struct damon_target *t); |
f23b8eee | 698 | |
2224d848 SP |
699 | struct damon_ctx *damon_new_ctx(void); |
700 | void damon_destroy_ctx(struct damon_ctx *ctx); | |
bead3b00 | 701 | int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs); |
cc713520 | 702 | void damon_set_schemes(struct damon_ctx *ctx, |
1f366e42 | 703 | struct damos **schemes, ssize_t nr_schemes); |
4bc05954 | 704 | int damon_nr_running_ctxs(void); |
152e5617 | 705 | bool damon_is_registered_ops(enum damon_ops_id id); |
9f7b053a SP |
706 | int damon_register_ops(struct damon_operations *ops); |
707 | int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id); | |
2224d848 | 708 | |
c9e124e0 SP |
709 | static inline bool damon_target_has_pid(const struct damon_ctx *ctx) |
710 | { | |
711 | return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR; | |
712 | } | |
713 | ||
35f5d941 SP |
714 | static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs) |
715 | { | |
716 | /* {aggr,sample}_interval are unsigned long, hence could overflow */ | |
717 | return min(attrs->aggr_interval / attrs->sample_interval, | |
718 | (unsigned long)UINT_MAX); | |
719 | } | |
720 | ||
c9e124e0 | 721 | |
8b9b0d33 | 722 | int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive); |
2224d848 SP |
723 | int damon_stop(struct damon_ctx **ctxs, int nr_ctxs); |
724 | ||
233f0b31 KX |
725 | int damon_set_region_biggest_system_ram_default(struct damon_target *t, |
726 | unsigned long *start, unsigned long *end); | |
0d83b2d8 | 727 | |
2224d848 SP |
728 | #endif /* CONFIG_DAMON */ |
729 | ||
730 | #endif /* _DAMON_H */ |