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2224d848 SP |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Data Access Monitor | |
4 | * | |
5 | * Author: SeongJae Park <sjpark@amazon.de> | |
6 | */ | |
7 | ||
8 | #define pr_fmt(fmt) "damon: " fmt | |
9 | ||
10 | #include <linux/damon.h> | |
11 | #include <linux/delay.h> | |
12 | #include <linux/kthread.h> | |
ee801b7d | 13 | #include <linux/mm.h> |
2224d848 | 14 | #include <linux/slab.h> |
38683e00 | 15 | #include <linux/string.h> |
2224d848 | 16 | |
2fcb9362 SP |
17 | #define CREATE_TRACE_POINTS |
18 | #include <trace/events/damon.h> | |
19 | ||
17ccae8b SP |
20 | #ifdef CONFIG_DAMON_KUNIT_TEST |
21 | #undef DAMON_MIN_REGION | |
22 | #define DAMON_MIN_REGION 1 | |
23 | #endif | |
24 | ||
2224d848 SP |
25 | static DEFINE_MUTEX(damon_lock); |
26 | static int nr_running_ctxs; | |
8b9b0d33 | 27 | static bool running_exclusive_ctxs; |
2224d848 | 28 | |
9f7b053a SP |
29 | static DEFINE_MUTEX(damon_ops_lock); |
30 | static struct damon_operations damon_registered_ops[NR_DAMON_OPS]; | |
31 | ||
a1870944 DL |
32 | static struct kmem_cache *damon_region_cache __ro_after_init; |
33 | ||
9f7b053a | 34 | /* Should be called under damon_ops_lock with id smaller than NR_DAMON_OPS */ |
152e5617 | 35 | static bool __damon_is_registered_ops(enum damon_ops_id id) |
9f7b053a SP |
36 | { |
37 | struct damon_operations empty_ops = {}; | |
38 | ||
39 | if (!memcmp(&empty_ops, &damon_registered_ops[id], sizeof(empty_ops))) | |
40 | return false; | |
41 | return true; | |
42 | } | |
43 | ||
152e5617 SP |
44 | /** |
45 | * damon_is_registered_ops() - Check if a given damon_operations is registered. | |
46 | * @id: Id of the damon_operations to check if registered. | |
47 | * | |
48 | * Return: true if the ops is set, false otherwise. | |
49 | */ | |
50 | bool damon_is_registered_ops(enum damon_ops_id id) | |
51 | { | |
52 | bool registered; | |
53 | ||
54 | if (id >= NR_DAMON_OPS) | |
55 | return false; | |
56 | mutex_lock(&damon_ops_lock); | |
57 | registered = __damon_is_registered_ops(id); | |
58 | mutex_unlock(&damon_ops_lock); | |
59 | return registered; | |
60 | } | |
61 | ||
9f7b053a SP |
62 | /** |
63 | * damon_register_ops() - Register a monitoring operations set to DAMON. | |
64 | * @ops: monitoring operations set to register. | |
65 | * | |
66 | * This function registers a monitoring operations set of valid &struct | |
67 | * damon_operations->id so that others can find and use them later. | |
68 | * | |
69 | * Return: 0 on success, negative error code otherwise. | |
70 | */ | |
71 | int damon_register_ops(struct damon_operations *ops) | |
72 | { | |
73 | int err = 0; | |
74 | ||
75 | if (ops->id >= NR_DAMON_OPS) | |
76 | return -EINVAL; | |
77 | mutex_lock(&damon_ops_lock); | |
78 | /* Fail for already registered ops */ | |
152e5617 | 79 | if (__damon_is_registered_ops(ops->id)) { |
9f7b053a SP |
80 | err = -EINVAL; |
81 | goto out; | |
82 | } | |
83 | damon_registered_ops[ops->id] = *ops; | |
84 | out: | |
85 | mutex_unlock(&damon_ops_lock); | |
86 | return err; | |
87 | } | |
88 | ||
89 | /** | |
90 | * damon_select_ops() - Select a monitoring operations to use with the context. | |
91 | * @ctx: monitoring context to use the operations. | |
92 | * @id: id of the registered monitoring operations to select. | |
93 | * | |
94 | * This function finds registered monitoring operations set of @id and make | |
95 | * @ctx to use it. | |
96 | * | |
97 | * Return: 0 on success, negative error code otherwise. | |
98 | */ | |
99 | int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id) | |
100 | { | |
101 | int err = 0; | |
102 | ||
103 | if (id >= NR_DAMON_OPS) | |
104 | return -EINVAL; | |
105 | ||
106 | mutex_lock(&damon_ops_lock); | |
152e5617 | 107 | if (!__damon_is_registered_ops(id)) |
9f7b053a SP |
108 | err = -EINVAL; |
109 | else | |
110 | ctx->ops = damon_registered_ops[id]; | |
111 | mutex_unlock(&damon_ops_lock); | |
112 | return err; | |
113 | } | |
114 | ||
f23b8eee SP |
115 | /* |
116 | * Construct a damon_region struct | |
117 | * | |
118 | * Returns the pointer to the new struct if success, or NULL otherwise | |
119 | */ | |
120 | struct damon_region *damon_new_region(unsigned long start, unsigned long end) | |
121 | { | |
122 | struct damon_region *region; | |
123 | ||
a1870944 | 124 | region = kmem_cache_alloc(damon_region_cache, GFP_KERNEL); |
f23b8eee SP |
125 | if (!region) |
126 | return NULL; | |
127 | ||
128 | region->ar.start = start; | |
129 | region->ar.end = end; | |
130 | region->nr_accesses = 0; | |
131 | INIT_LIST_HEAD(®ion->list); | |
132 | ||
fda504fa SP |
133 | region->age = 0; |
134 | region->last_nr_accesses = 0; | |
135 | ||
f23b8eee SP |
136 | return region; |
137 | } | |
138 | ||
f23b8eee SP |
139 | void damon_add_region(struct damon_region *r, struct damon_target *t) |
140 | { | |
141 | list_add_tail(&r->list, &t->regions_list); | |
b9a6ac4e | 142 | t->nr_regions++; |
f23b8eee SP |
143 | } |
144 | ||
b9a6ac4e | 145 | static void damon_del_region(struct damon_region *r, struct damon_target *t) |
f23b8eee SP |
146 | { |
147 | list_del(&r->list); | |
b9a6ac4e | 148 | t->nr_regions--; |
f23b8eee SP |
149 | } |
150 | ||
151 | static void damon_free_region(struct damon_region *r) | |
152 | { | |
a1870944 | 153 | kmem_cache_free(damon_region_cache, r); |
f23b8eee SP |
154 | } |
155 | ||
b9a6ac4e | 156 | void damon_destroy_region(struct damon_region *r, struct damon_target *t) |
f23b8eee | 157 | { |
b9a6ac4e | 158 | damon_del_region(r, t); |
f23b8eee SP |
159 | damon_free_region(r); |
160 | } | |
161 | ||
d0723bc0 SP |
162 | /* |
163 | * Check whether a region is intersecting an address range | |
164 | * | |
165 | * Returns true if it is. | |
166 | */ | |
167 | static bool damon_intersect(struct damon_region *r, | |
168 | struct damon_addr_range *re) | |
169 | { | |
170 | return !(r->ar.end <= re->start || re->end <= r->ar.start); | |
171 | } | |
172 | ||
9c950c22 SP |
173 | /* |
174 | * Fill holes in regions with new regions. | |
175 | */ | |
176 | static int damon_fill_regions_holes(struct damon_region *first, | |
177 | struct damon_region *last, struct damon_target *t) | |
178 | { | |
179 | struct damon_region *r = first; | |
180 | ||
181 | damon_for_each_region_from(r, t) { | |
182 | struct damon_region *next, *newr; | |
183 | ||
184 | if (r == last) | |
185 | break; | |
186 | next = damon_next_region(r); | |
187 | if (r->ar.end != next->ar.start) { | |
188 | newr = damon_new_region(r->ar.end, next->ar.start); | |
189 | if (!newr) | |
190 | return -ENOMEM; | |
191 | damon_insert_region(newr, r, next, t); | |
192 | } | |
193 | } | |
194 | return 0; | |
195 | } | |
196 | ||
d0723bc0 SP |
197 | /* |
198 | * damon_set_regions() - Set regions of a target for given address ranges. | |
199 | * @t: the given target. | |
200 | * @ranges: array of new monitoring target ranges. | |
201 | * @nr_ranges: length of @ranges. | |
202 | * | |
203 | * This function adds new regions to, or modify existing regions of a | |
204 | * monitoring target to fit in specific ranges. | |
205 | * | |
206 | * Return: 0 if success, or negative error code otherwise. | |
207 | */ | |
208 | int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, | |
209 | unsigned int nr_ranges) | |
210 | { | |
211 | struct damon_region *r, *next; | |
212 | unsigned int i; | |
9c950c22 | 213 | int err; |
d0723bc0 SP |
214 | |
215 | /* Remove regions which are not in the new ranges */ | |
216 | damon_for_each_region_safe(r, next, t) { | |
217 | for (i = 0; i < nr_ranges; i++) { | |
218 | if (damon_intersect(r, &ranges[i])) | |
219 | break; | |
220 | } | |
221 | if (i == nr_ranges) | |
222 | damon_destroy_region(r, t); | |
223 | } | |
224 | ||
36001cba | 225 | r = damon_first_region(t); |
d0723bc0 SP |
226 | /* Add new regions or resize existing regions to fit in the ranges */ |
227 | for (i = 0; i < nr_ranges; i++) { | |
228 | struct damon_region *first = NULL, *last, *newr; | |
229 | struct damon_addr_range *range; | |
230 | ||
231 | range = &ranges[i]; | |
232 | /* Get the first/last regions intersecting with the range */ | |
36001cba | 233 | damon_for_each_region_from(r, t) { |
d0723bc0 SP |
234 | if (damon_intersect(r, range)) { |
235 | if (!first) | |
236 | first = r; | |
237 | last = r; | |
238 | } | |
239 | if (r->ar.start >= range->end) | |
240 | break; | |
241 | } | |
242 | if (!first) { | |
243 | /* no region intersects with this range */ | |
244 | newr = damon_new_region( | |
245 | ALIGN_DOWN(range->start, | |
246 | DAMON_MIN_REGION), | |
247 | ALIGN(range->end, DAMON_MIN_REGION)); | |
248 | if (!newr) | |
249 | return -ENOMEM; | |
250 | damon_insert_region(newr, damon_prev_region(r), r, t); | |
251 | } else { | |
252 | /* resize intersecting regions to fit in this range */ | |
253 | first->ar.start = ALIGN_DOWN(range->start, | |
254 | DAMON_MIN_REGION); | |
255 | last->ar.end = ALIGN(range->end, DAMON_MIN_REGION); | |
9c950c22 SP |
256 | |
257 | /* fill possible holes in the range */ | |
258 | err = damon_fill_regions_holes(first, last, t); | |
259 | if (err) | |
260 | return err; | |
d0723bc0 SP |
261 | } |
262 | } | |
263 | return 0; | |
264 | } | |
265 | ||
98def236 SP |
266 | struct damos_filter *damos_new_filter(enum damos_filter_type type, |
267 | bool matching) | |
268 | { | |
269 | struct damos_filter *filter; | |
270 | ||
271 | filter = kmalloc(sizeof(*filter), GFP_KERNEL); | |
272 | if (!filter) | |
273 | return NULL; | |
274 | filter->type = type; | |
275 | filter->matching = matching; | |
5f1fc67f | 276 | INIT_LIST_HEAD(&filter->list); |
98def236 SP |
277 | return filter; |
278 | } | |
279 | ||
280 | void damos_add_filter(struct damos *s, struct damos_filter *f) | |
281 | { | |
282 | list_add_tail(&f->list, &s->filters); | |
283 | } | |
284 | ||
285 | static void damos_del_filter(struct damos_filter *f) | |
286 | { | |
287 | list_del(&f->list); | |
288 | } | |
289 | ||
290 | static void damos_free_filter(struct damos_filter *f) | |
291 | { | |
292 | kfree(f); | |
293 | } | |
294 | ||
295 | void damos_destroy_filter(struct damos_filter *f) | |
296 | { | |
297 | damos_del_filter(f); | |
298 | damos_free_filter(f); | |
299 | } | |
300 | ||
70e0c1d1 SP |
301 | /* initialize private fields of damos_quota and return the pointer */ |
302 | static struct damos_quota *damos_quota_init_priv(struct damos_quota *quota) | |
303 | { | |
304 | quota->total_charged_sz = 0; | |
305 | quota->total_charged_ns = 0; | |
306 | quota->esz = 0; | |
307 | quota->charged_sz = 0; | |
308 | quota->charged_from = 0; | |
309 | quota->charge_target_from = NULL; | |
310 | quota->charge_addr_from = 0; | |
311 | return quota; | |
312 | } | |
313 | ||
f5a79d7c YD |
314 | struct damos *damon_new_scheme(struct damos_access_pattern *pattern, |
315 | enum damos_action action, struct damos_quota *quota, | |
316 | struct damos_watermarks *wmarks) | |
1f366e42 SP |
317 | { |
318 | struct damos *scheme; | |
319 | ||
320 | scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); | |
321 | if (!scheme) | |
322 | return NULL; | |
02f17037 | 323 | scheme->pattern = *pattern; |
1f366e42 | 324 | scheme->action = action; |
98def236 | 325 | INIT_LIST_HEAD(&scheme->filters); |
0e92c2ee | 326 | scheme->stat = (struct damos_stat){}; |
1f366e42 SP |
327 | INIT_LIST_HEAD(&scheme->list); |
328 | ||
70e0c1d1 | 329 | scheme->quota = *(damos_quota_init_priv(quota)); |
2b8a248d | 330 | |
02f17037 | 331 | scheme->wmarks = *wmarks; |
ee801b7d SP |
332 | scheme->wmarks.activated = true; |
333 | ||
1f366e42 SP |
334 | return scheme; |
335 | } | |
336 | ||
337 | void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) | |
338 | { | |
339 | list_add_tail(&s->list, &ctx->schemes); | |
340 | } | |
341 | ||
342 | static void damon_del_scheme(struct damos *s) | |
343 | { | |
344 | list_del(&s->list); | |
345 | } | |
346 | ||
347 | static void damon_free_scheme(struct damos *s) | |
348 | { | |
349 | kfree(s); | |
350 | } | |
351 | ||
352 | void damon_destroy_scheme(struct damos *s) | |
353 | { | |
98def236 SP |
354 | struct damos_filter *f, *next; |
355 | ||
356 | damos_for_each_filter_safe(f, next, s) | |
357 | damos_destroy_filter(f); | |
1f366e42 SP |
358 | damon_del_scheme(s); |
359 | damon_free_scheme(s); | |
360 | } | |
361 | ||
f23b8eee SP |
362 | /* |
363 | * Construct a damon_target struct | |
364 | * | |
365 | * Returns the pointer to the new struct if success, or NULL otherwise | |
366 | */ | |
1971bd63 | 367 | struct damon_target *damon_new_target(void) |
f23b8eee SP |
368 | { |
369 | struct damon_target *t; | |
370 | ||
371 | t = kmalloc(sizeof(*t), GFP_KERNEL); | |
372 | if (!t) | |
373 | return NULL; | |
374 | ||
1971bd63 | 375 | t->pid = NULL; |
b9a6ac4e | 376 | t->nr_regions = 0; |
f23b8eee | 377 | INIT_LIST_HEAD(&t->regions_list); |
b1f44cda | 378 | INIT_LIST_HEAD(&t->list); |
f23b8eee SP |
379 | |
380 | return t; | |
381 | } | |
382 | ||
383 | void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) | |
384 | { | |
b9a6ac4e | 385 | list_add_tail(&t->list, &ctx->adaptive_targets); |
f23b8eee SP |
386 | } |
387 | ||
b5ca3e83 XH |
388 | bool damon_targets_empty(struct damon_ctx *ctx) |
389 | { | |
390 | return list_empty(&ctx->adaptive_targets); | |
391 | } | |
392 | ||
f23b8eee SP |
393 | static void damon_del_target(struct damon_target *t) |
394 | { | |
395 | list_del(&t->list); | |
396 | } | |
397 | ||
398 | void damon_free_target(struct damon_target *t) | |
399 | { | |
400 | struct damon_region *r, *next; | |
401 | ||
402 | damon_for_each_region_safe(r, next, t) | |
403 | damon_free_region(r); | |
404 | kfree(t); | |
405 | } | |
406 | ||
407 | void damon_destroy_target(struct damon_target *t) | |
408 | { | |
409 | damon_del_target(t); | |
410 | damon_free_target(t); | |
411 | } | |
412 | ||
b9a6ac4e SP |
413 | unsigned int damon_nr_regions(struct damon_target *t) |
414 | { | |
415 | return t->nr_regions; | |
416 | } | |
417 | ||
2224d848 SP |
418 | struct damon_ctx *damon_new_ctx(void) |
419 | { | |
420 | struct damon_ctx *ctx; | |
421 | ||
422 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); | |
423 | if (!ctx) | |
424 | return NULL; | |
425 | ||
cbeaa77b SP |
426 | ctx->attrs.sample_interval = 5 * 1000; |
427 | ctx->attrs.aggr_interval = 100 * 1000; | |
428 | ctx->attrs.ops_update_interval = 60 * 1000 * 1000; | |
2224d848 SP |
429 | |
430 | ktime_get_coarse_ts64(&ctx->last_aggregation); | |
f7d911c3 | 431 | ctx->last_ops_update = ctx->last_aggregation; |
2224d848 SP |
432 | |
433 | mutex_init(&ctx->kdamond_lock); | |
434 | ||
cbeaa77b SP |
435 | ctx->attrs.min_nr_regions = 10; |
436 | ctx->attrs.max_nr_regions = 1000; | |
b9a6ac4e SP |
437 | |
438 | INIT_LIST_HEAD(&ctx->adaptive_targets); | |
1f366e42 | 439 | INIT_LIST_HEAD(&ctx->schemes); |
2224d848 SP |
440 | |
441 | return ctx; | |
442 | } | |
443 | ||
f23b8eee | 444 | static void damon_destroy_targets(struct damon_ctx *ctx) |
2224d848 | 445 | { |
f23b8eee SP |
446 | struct damon_target *t, *next_t; |
447 | ||
f7d911c3 SP |
448 | if (ctx->ops.cleanup) { |
449 | ctx->ops.cleanup(ctx); | |
f23b8eee SP |
450 | return; |
451 | } | |
452 | ||
453 | damon_for_each_target_safe(t, next_t, ctx) | |
454 | damon_destroy_target(t); | |
455 | } | |
456 | ||
457 | void damon_destroy_ctx(struct damon_ctx *ctx) | |
458 | { | |
1f366e42 SP |
459 | struct damos *s, *next_s; |
460 | ||
f23b8eee | 461 | damon_destroy_targets(ctx); |
1f366e42 SP |
462 | |
463 | damon_for_each_scheme_safe(s, next_s, ctx) | |
464 | damon_destroy_scheme(s); | |
465 | ||
2224d848 SP |
466 | kfree(ctx); |
467 | } | |
468 | ||
2f5bef5a SP |
469 | static unsigned int damon_age_for_new_attrs(unsigned int age, |
470 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
471 | { | |
472 | return age * old_attrs->aggr_interval / new_attrs->aggr_interval; | |
473 | } | |
474 | ||
475 | /* convert access ratio in bp (per 10,000) to nr_accesses */ | |
476 | static unsigned int damon_accesses_bp_to_nr_accesses( | |
477 | unsigned int accesses_bp, struct damon_attrs *attrs) | |
478 | { | |
479 | unsigned int max_nr_accesses = | |
480 | attrs->aggr_interval / attrs->sample_interval; | |
481 | ||
482 | return accesses_bp * max_nr_accesses / 10000; | |
483 | } | |
484 | ||
485 | /* convert nr_accesses to access ratio in bp (per 10,000) */ | |
486 | static unsigned int damon_nr_accesses_to_accesses_bp( | |
487 | unsigned int nr_accesses, struct damon_attrs *attrs) | |
488 | { | |
489 | unsigned int max_nr_accesses = | |
490 | attrs->aggr_interval / attrs->sample_interval; | |
491 | ||
492 | return nr_accesses * 10000 / max_nr_accesses; | |
493 | } | |
494 | ||
495 | static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses, | |
496 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
497 | { | |
498 | return damon_accesses_bp_to_nr_accesses( | |
499 | damon_nr_accesses_to_accesses_bp( | |
500 | nr_accesses, old_attrs), | |
501 | new_attrs); | |
502 | } | |
503 | ||
504 | static void damon_update_monitoring_result(struct damon_region *r, | |
505 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
506 | { | |
507 | r->nr_accesses = damon_nr_accesses_for_new_attrs(r->nr_accesses, | |
508 | old_attrs, new_attrs); | |
509 | r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs); | |
510 | } | |
511 | ||
512 | /* | |
513 | * region->nr_accesses is the number of sampling intervals in the last | |
514 | * aggregation interval that access to the region has found, and region->age is | |
515 | * the number of aggregation intervals that its access pattern has maintained. | |
516 | * For the reason, the real meaning of the two fields depend on current | |
517 | * sampling interval and aggregation interval. This function updates | |
518 | * ->nr_accesses and ->age of given damon_ctx's regions for new damon_attrs. | |
519 | */ | |
520 | static void damon_update_monitoring_results(struct damon_ctx *ctx, | |
521 | struct damon_attrs *new_attrs) | |
522 | { | |
523 | struct damon_attrs *old_attrs = &ctx->attrs; | |
524 | struct damon_target *t; | |
525 | struct damon_region *r; | |
526 | ||
527 | /* if any interval is zero, simply forgive conversion */ | |
528 | if (!old_attrs->sample_interval || !old_attrs->aggr_interval || | |
529 | !new_attrs->sample_interval || | |
530 | !new_attrs->aggr_interval) | |
531 | return; | |
532 | ||
533 | damon_for_each_target(t, ctx) | |
534 | damon_for_each_region(r, t) | |
535 | damon_update_monitoring_result( | |
536 | r, old_attrs, new_attrs); | |
537 | } | |
538 | ||
2224d848 SP |
539 | /** |
540 | * damon_set_attrs() - Set attributes for the monitoring. | |
541 | * @ctx: monitoring context | |
bead3b00 | 542 | * @attrs: monitoring attributes |
2224d848 SP |
543 | * |
544 | * This function should not be called while the kdamond is running. | |
545 | * Every time interval is in micro-seconds. | |
546 | * | |
547 | * Return: 0 on success, negative error code otherwise. | |
548 | */ | |
bead3b00 | 549 | int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs) |
2224d848 | 550 | { |
bead3b00 | 551 | if (attrs->min_nr_regions < 3) |
b9a6ac4e | 552 | return -EINVAL; |
bead3b00 | 553 | if (attrs->min_nr_regions > attrs->max_nr_regions) |
b9a6ac4e | 554 | return -EINVAL; |
5ff6e2ff KW |
555 | if (attrs->sample_interval > attrs->aggr_interval) |
556 | return -EINVAL; | |
b9a6ac4e | 557 | |
2f5bef5a | 558 | damon_update_monitoring_results(ctx, attrs); |
bead3b00 | 559 | ctx->attrs = *attrs; |
2224d848 SP |
560 | return 0; |
561 | } | |
562 | ||
1f366e42 SP |
563 | /** |
564 | * damon_set_schemes() - Set data access monitoring based operation schemes. | |
565 | * @ctx: monitoring context | |
566 | * @schemes: array of the schemes | |
567 | * @nr_schemes: number of entries in @schemes | |
568 | * | |
569 | * This function should not be called while the kdamond of the context is | |
570 | * running. | |
1f366e42 | 571 | */ |
cc713520 | 572 | void damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, |
1f366e42 SP |
573 | ssize_t nr_schemes) |
574 | { | |
575 | struct damos *s, *next; | |
576 | ssize_t i; | |
577 | ||
578 | damon_for_each_scheme_safe(s, next, ctx) | |
579 | damon_destroy_scheme(s); | |
580 | for (i = 0; i < nr_schemes; i++) | |
581 | damon_add_scheme(ctx, schemes[i]); | |
1f366e42 SP |
582 | } |
583 | ||
4bc05954 SP |
584 | /** |
585 | * damon_nr_running_ctxs() - Return number of currently running contexts. | |
586 | */ | |
587 | int damon_nr_running_ctxs(void) | |
588 | { | |
589 | int nr_ctxs; | |
590 | ||
591 | mutex_lock(&damon_lock); | |
592 | nr_ctxs = nr_running_ctxs; | |
593 | mutex_unlock(&damon_lock); | |
594 | ||
595 | return nr_ctxs; | |
596 | } | |
597 | ||
b9a6ac4e SP |
598 | /* Returns the size upper limit for each monitoring region */ |
599 | static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) | |
600 | { | |
601 | struct damon_target *t; | |
602 | struct damon_region *r; | |
603 | unsigned long sz = 0; | |
604 | ||
605 | damon_for_each_target(t, ctx) { | |
606 | damon_for_each_region(r, t) | |
ab63f63f | 607 | sz += damon_sz_region(r); |
b9a6ac4e SP |
608 | } |
609 | ||
cbeaa77b SP |
610 | if (ctx->attrs.min_nr_regions) |
611 | sz /= ctx->attrs.min_nr_regions; | |
b9a6ac4e SP |
612 | if (sz < DAMON_MIN_REGION) |
613 | sz = DAMON_MIN_REGION; | |
614 | ||
615 | return sz; | |
616 | } | |
617 | ||
2224d848 SP |
618 | static int kdamond_fn(void *data); |
619 | ||
620 | /* | |
621 | * __damon_start() - Starts monitoring with given context. | |
622 | * @ctx: monitoring context | |
623 | * | |
624 | * This function should be called while damon_lock is hold. | |
625 | * | |
626 | * Return: 0 on success, negative error code otherwise. | |
627 | */ | |
628 | static int __damon_start(struct damon_ctx *ctx) | |
629 | { | |
630 | int err = -EBUSY; | |
631 | ||
632 | mutex_lock(&ctx->kdamond_lock); | |
633 | if (!ctx->kdamond) { | |
634 | err = 0; | |
2224d848 SP |
635 | ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", |
636 | nr_running_ctxs); | |
637 | if (IS_ERR(ctx->kdamond)) { | |
638 | err = PTR_ERR(ctx->kdamond); | |
7ec1992b | 639 | ctx->kdamond = NULL; |
2224d848 SP |
640 | } |
641 | } | |
642 | mutex_unlock(&ctx->kdamond_lock); | |
643 | ||
644 | return err; | |
645 | } | |
646 | ||
647 | /** | |
648 | * damon_start() - Starts the monitorings for a given group of contexts. | |
649 | * @ctxs: an array of the pointers for contexts to start monitoring | |
650 | * @nr_ctxs: size of @ctxs | |
8b9b0d33 | 651 | * @exclusive: exclusiveness of this contexts group |
2224d848 SP |
652 | * |
653 | * This function starts a group of monitoring threads for a group of monitoring | |
654 | * contexts. One thread per each context is created and run in parallel. The | |
8b9b0d33 SP |
655 | * caller should handle synchronization between the threads by itself. If |
656 | * @exclusive is true and a group of threads that created by other | |
657 | * 'damon_start()' call is currently running, this function does nothing but | |
658 | * returns -EBUSY. | |
2224d848 SP |
659 | * |
660 | * Return: 0 on success, negative error code otherwise. | |
661 | */ | |
8b9b0d33 | 662 | int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive) |
2224d848 SP |
663 | { |
664 | int i; | |
665 | int err = 0; | |
666 | ||
667 | mutex_lock(&damon_lock); | |
8b9b0d33 SP |
668 | if ((exclusive && nr_running_ctxs) || |
669 | (!exclusive && running_exclusive_ctxs)) { | |
2224d848 SP |
670 | mutex_unlock(&damon_lock); |
671 | return -EBUSY; | |
672 | } | |
673 | ||
674 | for (i = 0; i < nr_ctxs; i++) { | |
675 | err = __damon_start(ctxs[i]); | |
676 | if (err) | |
677 | break; | |
678 | nr_running_ctxs++; | |
679 | } | |
8b9b0d33 SP |
680 | if (exclusive && nr_running_ctxs) |
681 | running_exclusive_ctxs = true; | |
2224d848 SP |
682 | mutex_unlock(&damon_lock); |
683 | ||
684 | return err; | |
685 | } | |
686 | ||
687 | /* | |
8b9b0d33 | 688 | * __damon_stop() - Stops monitoring of a given context. |
2224d848 SP |
689 | * @ctx: monitoring context |
690 | * | |
691 | * Return: 0 on success, negative error code otherwise. | |
692 | */ | |
693 | static int __damon_stop(struct damon_ctx *ctx) | |
694 | { | |
0f91d133 CD |
695 | struct task_struct *tsk; |
696 | ||
2224d848 | 697 | mutex_lock(&ctx->kdamond_lock); |
0f91d133 CD |
698 | tsk = ctx->kdamond; |
699 | if (tsk) { | |
700 | get_task_struct(tsk); | |
2224d848 | 701 | mutex_unlock(&ctx->kdamond_lock); |
0f91d133 CD |
702 | kthread_stop(tsk); |
703 | put_task_struct(tsk); | |
2224d848 SP |
704 | return 0; |
705 | } | |
706 | mutex_unlock(&ctx->kdamond_lock); | |
707 | ||
708 | return -EPERM; | |
709 | } | |
710 | ||
711 | /** | |
712 | * damon_stop() - Stops the monitorings for a given group of contexts. | |
713 | * @ctxs: an array of the pointers for contexts to stop monitoring | |
714 | * @nr_ctxs: size of @ctxs | |
715 | * | |
716 | * Return: 0 on success, negative error code otherwise. | |
717 | */ | |
718 | int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) | |
719 | { | |
720 | int i, err = 0; | |
721 | ||
722 | for (i = 0; i < nr_ctxs; i++) { | |
723 | /* nr_running_ctxs is decremented in kdamond_fn */ | |
724 | err = __damon_stop(ctxs[i]); | |
725 | if (err) | |
8b9b0d33 | 726 | break; |
2224d848 | 727 | } |
2224d848 SP |
728 | return err; |
729 | } | |
730 | ||
731 | /* | |
732 | * damon_check_reset_time_interval() - Check if a time interval is elapsed. | |
733 | * @baseline: the time to check whether the interval has elapsed since | |
734 | * @interval: the time interval (microseconds) | |
735 | * | |
736 | * See whether the given time interval has passed since the given baseline | |
737 | * time. If so, it also updates the baseline to current time for next check. | |
738 | * | |
739 | * Return: true if the time interval has passed, or false otherwise. | |
740 | */ | |
741 | static bool damon_check_reset_time_interval(struct timespec64 *baseline, | |
742 | unsigned long interval) | |
743 | { | |
744 | struct timespec64 now; | |
745 | ||
746 | ktime_get_coarse_ts64(&now); | |
747 | if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) < | |
748 | interval * 1000) | |
749 | return false; | |
750 | *baseline = now; | |
751 | return true; | |
752 | } | |
753 | ||
754 | /* | |
755 | * Check whether it is time to flush the aggregated information | |
756 | */ | |
757 | static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) | |
758 | { | |
759 | return damon_check_reset_time_interval(&ctx->last_aggregation, | |
cbeaa77b | 760 | ctx->attrs.aggr_interval); |
2224d848 SP |
761 | } |
762 | ||
f23b8eee SP |
763 | /* |
764 | * Reset the aggregated monitoring results ('nr_accesses' of each region). | |
765 | */ | |
766 | static void kdamond_reset_aggregated(struct damon_ctx *c) | |
767 | { | |
768 | struct damon_target *t; | |
76fd0285 | 769 | unsigned int ti = 0; /* target's index */ |
f23b8eee SP |
770 | |
771 | damon_for_each_target(t, c) { | |
772 | struct damon_region *r; | |
773 | ||
2fcb9362 | 774 | damon_for_each_region(r, t) { |
76fd0285 | 775 | trace_damon_aggregated(t, ti, r, damon_nr_regions(t)); |
fda504fa | 776 | r->last_nr_accesses = r->nr_accesses; |
f23b8eee | 777 | r->nr_accesses = 0; |
2fcb9362 | 778 | } |
76fd0285 | 779 | ti++; |
f23b8eee SP |
780 | } |
781 | } | |
782 | ||
4ed98243 KX |
783 | static void damon_split_region_at(struct damon_target *t, |
784 | struct damon_region *r, unsigned long sz_r); | |
2b8a248d | 785 | |
38683e00 SP |
786 | static bool __damos_valid_target(struct damon_region *r, struct damos *s) |
787 | { | |
788 | unsigned long sz; | |
789 | ||
ab63f63f | 790 | sz = damon_sz_region(r); |
f5a79d7c YD |
791 | return s->pattern.min_sz_region <= sz && |
792 | sz <= s->pattern.max_sz_region && | |
793 | s->pattern.min_nr_accesses <= r->nr_accesses && | |
794 | r->nr_accesses <= s->pattern.max_nr_accesses && | |
795 | s->pattern.min_age_region <= r->age && | |
796 | r->age <= s->pattern.max_age_region; | |
38683e00 SP |
797 | } |
798 | ||
799 | static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, | |
800 | struct damon_region *r, struct damos *s) | |
801 | { | |
802 | bool ret = __damos_valid_target(r, s); | |
803 | ||
f7d911c3 | 804 | if (!ret || !s->quota.esz || !c->ops.get_scheme_score) |
38683e00 SP |
805 | return ret; |
806 | ||
f7d911c3 | 807 | return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; |
38683e00 SP |
808 | } |
809 | ||
2ea34989 SP |
810 | /* |
811 | * damos_skip_charged_region() - Check if the given region or starting part of | |
812 | * it is already charged for the DAMOS quota. | |
813 | * @t: The target of the region. | |
814 | * @rp: The pointer to the region. | |
815 | * @s: The scheme to be applied. | |
816 | * | |
817 | * If a quota of a scheme has exceeded in a quota charge window, the scheme's | |
818 | * action would applied to only a part of the target access pattern fulfilling | |
819 | * regions. To avoid applying the scheme action to only already applied | |
820 | * regions, DAMON skips applying the scheme action to the regions that charged | |
821 | * in the previous charge window. | |
822 | * | |
823 | * This function checks if a given region should be skipped or not for the | |
824 | * reason. If only the starting part of the region has previously charged, | |
825 | * this function splits the region into two so that the second one covers the | |
826 | * area that not charged in the previous charge widnow and saves the second | |
827 | * region in *rp and returns false, so that the caller can apply DAMON action | |
828 | * to the second one. | |
829 | * | |
830 | * Return: true if the region should be entirely skipped, false otherwise. | |
831 | */ | |
832 | static bool damos_skip_charged_region(struct damon_target *t, | |
833 | struct damon_region **rp, struct damos *s) | |
834 | { | |
835 | struct damon_region *r = *rp; | |
836 | struct damos_quota *quota = &s->quota; | |
837 | unsigned long sz_to_skip; | |
838 | ||
839 | /* Skip previously charged regions */ | |
840 | if (quota->charge_target_from) { | |
841 | if (t != quota->charge_target_from) | |
842 | return true; | |
843 | if (r == damon_last_region(t)) { | |
844 | quota->charge_target_from = NULL; | |
845 | quota->charge_addr_from = 0; | |
846 | return true; | |
847 | } | |
848 | if (quota->charge_addr_from && | |
849 | r->ar.end <= quota->charge_addr_from) | |
850 | return true; | |
851 | ||
852 | if (quota->charge_addr_from && r->ar.start < | |
853 | quota->charge_addr_from) { | |
854 | sz_to_skip = ALIGN_DOWN(quota->charge_addr_from - | |
855 | r->ar.start, DAMON_MIN_REGION); | |
856 | if (!sz_to_skip) { | |
857 | if (damon_sz_region(r) <= DAMON_MIN_REGION) | |
858 | return true; | |
859 | sz_to_skip = DAMON_MIN_REGION; | |
860 | } | |
861 | damon_split_region_at(t, r, sz_to_skip); | |
862 | r = damon_next_region(r); | |
863 | *rp = r; | |
864 | } | |
865 | quota->charge_target_from = NULL; | |
866 | quota->charge_addr_from = 0; | |
867 | } | |
868 | return false; | |
869 | } | |
870 | ||
d1cbbf62 SP |
871 | static void damos_update_stat(struct damos *s, |
872 | unsigned long sz_tried, unsigned long sz_applied) | |
873 | { | |
874 | s->stat.nr_tried++; | |
875 | s->stat.sz_tried += sz_tried; | |
876 | if (sz_applied) | |
877 | s->stat.nr_applied++; | |
878 | s->stat.sz_applied += sz_applied; | |
879 | } | |
880 | ||
e63a30c5 SP |
881 | static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, |
882 | struct damon_region *r, struct damos *s) | |
883 | { | |
884 | struct damos_quota *quota = &s->quota; | |
885 | unsigned long sz = damon_sz_region(r); | |
886 | struct timespec64 begin, end; | |
887 | unsigned long sz_applied = 0; | |
44467bbb | 888 | int err = 0; |
e63a30c5 SP |
889 | |
890 | if (c->ops.apply_scheme) { | |
891 | if (quota->esz && quota->charged_sz + sz > quota->esz) { | |
892 | sz = ALIGN_DOWN(quota->esz - quota->charged_sz, | |
893 | DAMON_MIN_REGION); | |
894 | if (!sz) | |
895 | goto update_stat; | |
896 | damon_split_region_at(t, r, sz); | |
897 | } | |
898 | ktime_get_coarse_ts64(&begin); | |
44467bbb SP |
899 | if (c->callback.before_damos_apply) |
900 | err = c->callback.before_damos_apply(c, t, r, s); | |
901 | if (!err) | |
902 | sz_applied = c->ops.apply_scheme(c, t, r, s); | |
e63a30c5 SP |
903 | ktime_get_coarse_ts64(&end); |
904 | quota->total_charged_ns += timespec64_to_ns(&end) - | |
905 | timespec64_to_ns(&begin); | |
906 | quota->charged_sz += sz; | |
907 | if (quota->esz && quota->charged_sz >= quota->esz) { | |
908 | quota->charge_target_from = t; | |
909 | quota->charge_addr_from = r->ar.end + 1; | |
910 | } | |
911 | } | |
912 | if (s->action != DAMOS_STAT) | |
913 | r->age = 0; | |
914 | ||
915 | update_stat: | |
d1cbbf62 | 916 | damos_update_stat(s, sz, sz_applied); |
e63a30c5 SP |
917 | } |
918 | ||
1f366e42 SP |
919 | static void damon_do_apply_schemes(struct damon_ctx *c, |
920 | struct damon_target *t, | |
921 | struct damon_region *r) | |
922 | { | |
923 | struct damos *s; | |
1f366e42 SP |
924 | |
925 | damon_for_each_scheme(s, c) { | |
2b8a248d | 926 | struct damos_quota *quota = &s->quota; |
2b8a248d | 927 | |
ee801b7d SP |
928 | if (!s->wmarks.activated) |
929 | continue; | |
930 | ||
2b8a248d | 931 | /* Check the quota */ |
1cd24303 | 932 | if (quota->esz && quota->charged_sz >= quota->esz) |
2b8a248d SP |
933 | continue; |
934 | ||
2ea34989 SP |
935 | if (damos_skip_charged_region(t, &r, s)) |
936 | continue; | |
50585192 | 937 | |
38683e00 | 938 | if (!damos_valid_target(c, t, r, s)) |
1f366e42 | 939 | continue; |
2b8a248d | 940 | |
e63a30c5 | 941 | damos_apply_scheme(c, t, r, s); |
1f366e42 SP |
942 | } |
943 | } | |
944 | ||
1cd24303 SP |
945 | /* Shouldn't be called if quota->ms and quota->sz are zero */ |
946 | static void damos_set_effective_quota(struct damos_quota *quota) | |
947 | { | |
948 | unsigned long throughput; | |
949 | unsigned long esz; | |
950 | ||
951 | if (!quota->ms) { | |
952 | quota->esz = quota->sz; | |
953 | return; | |
954 | } | |
955 | ||
956 | if (quota->total_charged_ns) | |
957 | throughput = quota->total_charged_sz * 1000000 / | |
958 | quota->total_charged_ns; | |
959 | else | |
960 | throughput = PAGE_SIZE * 1024; | |
961 | esz = throughput * quota->ms; | |
962 | ||
963 | if (quota->sz && quota->sz < esz) | |
964 | esz = quota->sz; | |
965 | quota->esz = esz; | |
966 | } | |
967 | ||
898810e5 | 968 | static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) |
1f366e42 | 969 | { |
898810e5 | 970 | struct damos_quota *quota = &s->quota; |
1f366e42 | 971 | struct damon_target *t; |
898810e5 SP |
972 | struct damon_region *r; |
973 | unsigned long cumulated_sz; | |
974 | unsigned int score, max_score = 0; | |
2b8a248d | 975 | |
898810e5 SP |
976 | if (!quota->ms && !quota->sz) |
977 | return; | |
2b8a248d | 978 | |
898810e5 SP |
979 | /* New charge window starts */ |
980 | if (time_after_eq(jiffies, quota->charged_from + | |
981 | msecs_to_jiffies(quota->reset_interval))) { | |
982 | if (quota->esz && quota->charged_sz >= quota->esz) | |
983 | s->stat.qt_exceeds++; | |
984 | quota->total_charged_sz += quota->charged_sz; | |
985 | quota->charged_from = jiffies; | |
986 | quota->charged_sz = 0; | |
987 | damos_set_effective_quota(quota); | |
988 | } | |
ee801b7d | 989 | |
898810e5 SP |
990 | if (!c->ops.get_scheme_score) |
991 | return; | |
2b8a248d | 992 | |
898810e5 SP |
993 | /* Fill up the score histogram */ |
994 | memset(quota->histogram, 0, sizeof(quota->histogram)); | |
995 | damon_for_each_target(t, c) { | |
996 | damon_for_each_region(r, t) { | |
997 | if (!__damos_valid_target(r, s)) | |
998 | continue; | |
999 | score = c->ops.get_scheme_score(c, t, r, s); | |
1000 | quota->histogram[score] += damon_sz_region(r); | |
1001 | if (score > max_score) | |
1002 | max_score = score; | |
2b8a248d | 1003 | } |
898810e5 | 1004 | } |
38683e00 | 1005 | |
898810e5 SP |
1006 | /* Set the min score limit */ |
1007 | for (cumulated_sz = 0, score = max_score; ; score--) { | |
1008 | cumulated_sz += quota->histogram[score]; | |
1009 | if (cumulated_sz >= quota->esz || !score) | |
1010 | break; | |
1011 | } | |
1012 | quota->min_score = score; | |
1013 | } | |
38683e00 | 1014 | |
898810e5 SP |
1015 | static void kdamond_apply_schemes(struct damon_ctx *c) |
1016 | { | |
1017 | struct damon_target *t; | |
1018 | struct damon_region *r, *next_r; | |
1019 | struct damos *s; | |
38683e00 | 1020 | |
898810e5 SP |
1021 | damon_for_each_scheme(s, c) { |
1022 | if (!s->wmarks.activated) | |
1023 | continue; | |
1024 | ||
1025 | damos_adjust_quota(c, s); | |
2b8a248d | 1026 | } |
1f366e42 SP |
1027 | |
1028 | damon_for_each_target(t, c) { | |
2b8a248d | 1029 | damon_for_each_region_safe(r, next_r, t) |
1f366e42 SP |
1030 | damon_do_apply_schemes(c, t, r); |
1031 | } | |
1032 | } | |
1033 | ||
b9a6ac4e SP |
1034 | /* |
1035 | * Merge two adjacent regions into one region | |
1036 | */ | |
1037 | static void damon_merge_two_regions(struct damon_target *t, | |
1038 | struct damon_region *l, struct damon_region *r) | |
1039 | { | |
652e0446 | 1040 | unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r); |
b9a6ac4e SP |
1041 | |
1042 | l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / | |
1043 | (sz_l + sz_r); | |
fda504fa | 1044 | l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); |
b9a6ac4e SP |
1045 | l->ar.end = r->ar.end; |
1046 | damon_destroy_region(r, t); | |
1047 | } | |
1048 | ||
b9a6ac4e SP |
1049 | /* |
1050 | * Merge adjacent regions having similar access frequencies | |
1051 | * | |
1052 | * t target affected by this merge operation | |
1053 | * thres '->nr_accesses' diff threshold for the merge | |
1054 | * sz_limit size upper limit of each region | |
1055 | */ | |
1056 | static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, | |
1057 | unsigned long sz_limit) | |
1058 | { | |
1059 | struct damon_region *r, *prev = NULL, *next; | |
1060 | ||
1061 | damon_for_each_region_safe(r, next, t) { | |
d720bbbd | 1062 | if (abs(r->nr_accesses - r->last_nr_accesses) > thres) |
fda504fa SP |
1063 | r->age = 0; |
1064 | else | |
1065 | r->age++; | |
1066 | ||
b9a6ac4e | 1067 | if (prev && prev->ar.end == r->ar.start && |
d720bbbd | 1068 | abs(prev->nr_accesses - r->nr_accesses) <= thres && |
652e0446 | 1069 | damon_sz_region(prev) + damon_sz_region(r) <= sz_limit) |
b9a6ac4e SP |
1070 | damon_merge_two_regions(t, prev, r); |
1071 | else | |
1072 | prev = r; | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * Merge adjacent regions having similar access frequencies | |
1078 | * | |
1079 | * threshold '->nr_accesses' diff threshold for the merge | |
1080 | * sz_limit size upper limit of each region | |
1081 | * | |
1082 | * This function merges monitoring target regions which are adjacent and their | |
1083 | * access frequencies are similar. This is for minimizing the monitoring | |
1084 | * overhead under the dynamically changeable access pattern. If a merge was | |
1085 | * unnecessarily made, later 'kdamond_split_regions()' will revert it. | |
1086 | */ | |
1087 | static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, | |
1088 | unsigned long sz_limit) | |
1089 | { | |
1090 | struct damon_target *t; | |
1091 | ||
1092 | damon_for_each_target(t, c) | |
1093 | damon_merge_regions_of(t, threshold, sz_limit); | |
1094 | } | |
1095 | ||
1096 | /* | |
1097 | * Split a region in two | |
1098 | * | |
1099 | * r the region to be split | |
1100 | * sz_r size of the first sub-region that will be made | |
1101 | */ | |
4ed98243 KX |
1102 | static void damon_split_region_at(struct damon_target *t, |
1103 | struct damon_region *r, unsigned long sz_r) | |
b9a6ac4e SP |
1104 | { |
1105 | struct damon_region *new; | |
1106 | ||
1107 | new = damon_new_region(r->ar.start + sz_r, r->ar.end); | |
1108 | if (!new) | |
1109 | return; | |
1110 | ||
1111 | r->ar.end = new->ar.start; | |
1112 | ||
fda504fa SP |
1113 | new->age = r->age; |
1114 | new->last_nr_accesses = r->last_nr_accesses; | |
1115 | ||
b9a6ac4e SP |
1116 | damon_insert_region(new, r, damon_next_region(r), t); |
1117 | } | |
1118 | ||
1119 | /* Split every region in the given target into 'nr_subs' regions */ | |
4ed98243 | 1120 | static void damon_split_regions_of(struct damon_target *t, int nr_subs) |
b9a6ac4e SP |
1121 | { |
1122 | struct damon_region *r, *next; | |
1123 | unsigned long sz_region, sz_sub = 0; | |
1124 | int i; | |
1125 | ||
1126 | damon_for_each_region_safe(r, next, t) { | |
ab63f63f | 1127 | sz_region = damon_sz_region(r); |
b9a6ac4e SP |
1128 | |
1129 | for (i = 0; i < nr_subs - 1 && | |
1130 | sz_region > 2 * DAMON_MIN_REGION; i++) { | |
1131 | /* | |
1132 | * Randomly select size of left sub-region to be at | |
1133 | * least 10 percent and at most 90% of original region | |
1134 | */ | |
1135 | sz_sub = ALIGN_DOWN(damon_rand(1, 10) * | |
1136 | sz_region / 10, DAMON_MIN_REGION); | |
1137 | /* Do not allow blank region */ | |
1138 | if (sz_sub == 0 || sz_sub >= sz_region) | |
1139 | continue; | |
1140 | ||
4ed98243 | 1141 | damon_split_region_at(t, r, sz_sub); |
b9a6ac4e SP |
1142 | sz_region = sz_sub; |
1143 | } | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * Split every target region into randomly-sized small regions | |
1149 | * | |
1150 | * This function splits every target region into random-sized small regions if | |
1151 | * current total number of the regions is equal or smaller than half of the | |
1152 | * user-specified maximum number of regions. This is for maximizing the | |
1153 | * monitoring accuracy under the dynamically changeable access patterns. If a | |
1154 | * split was unnecessarily made, later 'kdamond_merge_regions()' will revert | |
1155 | * it. | |
1156 | */ | |
1157 | static void kdamond_split_regions(struct damon_ctx *ctx) | |
1158 | { | |
1159 | struct damon_target *t; | |
1160 | unsigned int nr_regions = 0; | |
1161 | static unsigned int last_nr_regions; | |
1162 | int nr_subregions = 2; | |
1163 | ||
1164 | damon_for_each_target(t, ctx) | |
1165 | nr_regions += damon_nr_regions(t); | |
1166 | ||
cbeaa77b | 1167 | if (nr_regions > ctx->attrs.max_nr_regions / 2) |
b9a6ac4e SP |
1168 | return; |
1169 | ||
1170 | /* Maybe the middle of the region has different access frequency */ | |
1171 | if (last_nr_regions == nr_regions && | |
cbeaa77b | 1172 | nr_regions < ctx->attrs.max_nr_regions / 3) |
b9a6ac4e SP |
1173 | nr_subregions = 3; |
1174 | ||
1175 | damon_for_each_target(t, ctx) | |
4ed98243 | 1176 | damon_split_regions_of(t, nr_subregions); |
b9a6ac4e SP |
1177 | |
1178 | last_nr_regions = nr_regions; | |
1179 | } | |
1180 | ||
2224d848 | 1181 | /* |
f7d911c3 SP |
1182 | * Check whether it is time to check and apply the operations-related data |
1183 | * structures. | |
2224d848 SP |
1184 | * |
1185 | * Returns true if it is. | |
1186 | */ | |
f7d911c3 | 1187 | static bool kdamond_need_update_operations(struct damon_ctx *ctx) |
2224d848 | 1188 | { |
f7d911c3 | 1189 | return damon_check_reset_time_interval(&ctx->last_ops_update, |
cbeaa77b | 1190 | ctx->attrs.ops_update_interval); |
2224d848 SP |
1191 | } |
1192 | ||
1193 | /* | |
1194 | * Check whether current monitoring should be stopped | |
1195 | * | |
1196 | * The monitoring is stopped when either the user requested to stop, or all | |
1197 | * monitoring targets are invalid. | |
1198 | * | |
1199 | * Returns true if need to stop current monitoring. | |
1200 | */ | |
1201 | static bool kdamond_need_stop(struct damon_ctx *ctx) | |
1202 | { | |
f23b8eee | 1203 | struct damon_target *t; |
2224d848 | 1204 | |
0f91d133 | 1205 | if (kthread_should_stop()) |
2224d848 SP |
1206 | return true; |
1207 | ||
f7d911c3 | 1208 | if (!ctx->ops.target_valid) |
2224d848 SP |
1209 | return false; |
1210 | ||
f23b8eee | 1211 | damon_for_each_target(t, ctx) { |
f7d911c3 | 1212 | if (ctx->ops.target_valid(t)) |
f23b8eee SP |
1213 | return false; |
1214 | } | |
1215 | ||
1216 | return true; | |
2224d848 SP |
1217 | } |
1218 | ||
ee801b7d SP |
1219 | static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) |
1220 | { | |
1221 | struct sysinfo i; | |
1222 | ||
1223 | switch (metric) { | |
1224 | case DAMOS_WMARK_FREE_MEM_RATE: | |
1225 | si_meminfo(&i); | |
1226 | return i.freeram * 1000 / i.totalram; | |
1227 | default: | |
1228 | break; | |
1229 | } | |
1230 | return -EINVAL; | |
1231 | } | |
1232 | ||
1233 | /* | |
1234 | * Returns zero if the scheme is active. Else, returns time to wait for next | |
1235 | * watermark check in micro-seconds. | |
1236 | */ | |
1237 | static unsigned long damos_wmark_wait_us(struct damos *scheme) | |
1238 | { | |
1239 | unsigned long metric; | |
1240 | ||
1241 | if (scheme->wmarks.metric == DAMOS_WMARK_NONE) | |
1242 | return 0; | |
1243 | ||
1244 | metric = damos_wmark_metric_value(scheme->wmarks.metric); | |
1245 | /* higher than high watermark or lower than low watermark */ | |
1246 | if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { | |
1247 | if (scheme->wmarks.activated) | |
01078655 | 1248 | pr_debug("deactivate a scheme (%d) for %s wmark\n", |
ee801b7d SP |
1249 | scheme->action, |
1250 | metric > scheme->wmarks.high ? | |
1251 | "high" : "low"); | |
1252 | scheme->wmarks.activated = false; | |
1253 | return scheme->wmarks.interval; | |
1254 | } | |
1255 | ||
1256 | /* inactive and higher than middle watermark */ | |
1257 | if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && | |
1258 | !scheme->wmarks.activated) | |
1259 | return scheme->wmarks.interval; | |
1260 | ||
1261 | if (!scheme->wmarks.activated) | |
1262 | pr_debug("activate a scheme (%d)\n", scheme->action); | |
1263 | scheme->wmarks.activated = true; | |
1264 | return 0; | |
1265 | } | |
1266 | ||
1267 | static void kdamond_usleep(unsigned long usecs) | |
1268 | { | |
4de46a30 SP |
1269 | /* See Documentation/timers/timers-howto.rst for the thresholds */ |
1270 | if (usecs > 20 * USEC_PER_MSEC) | |
70e92748 | 1271 | schedule_timeout_idle(usecs_to_jiffies(usecs)); |
ee801b7d | 1272 | else |
70e92748 | 1273 | usleep_idle_range(usecs, usecs + 1); |
ee801b7d SP |
1274 | } |
1275 | ||
1276 | /* Returns negative error code if it's not activated but should return */ | |
1277 | static int kdamond_wait_activation(struct damon_ctx *ctx) | |
1278 | { | |
1279 | struct damos *s; | |
1280 | unsigned long wait_time; | |
1281 | unsigned long min_wait_time = 0; | |
78049e94 | 1282 | bool init_wait_time = false; |
ee801b7d SP |
1283 | |
1284 | while (!kdamond_need_stop(ctx)) { | |
1285 | damon_for_each_scheme(s, ctx) { | |
1286 | wait_time = damos_wmark_wait_us(s); | |
78049e94 JK |
1287 | if (!init_wait_time || wait_time < min_wait_time) { |
1288 | init_wait_time = true; | |
ee801b7d | 1289 | min_wait_time = wait_time; |
78049e94 | 1290 | } |
ee801b7d SP |
1291 | } |
1292 | if (!min_wait_time) | |
1293 | return 0; | |
1294 | ||
1295 | kdamond_usleep(min_wait_time); | |
6e74d2bf SP |
1296 | |
1297 | if (ctx->callback.after_wmarks_check && | |
1298 | ctx->callback.after_wmarks_check(ctx)) | |
1299 | break; | |
ee801b7d SP |
1300 | } |
1301 | return -EBUSY; | |
1302 | } | |
1303 | ||
2224d848 SP |
1304 | /* |
1305 | * The monitoring daemon that runs as a kernel thread | |
1306 | */ | |
1307 | static int kdamond_fn(void *data) | |
1308 | { | |
cef4493f | 1309 | struct damon_ctx *ctx = data; |
f23b8eee SP |
1310 | struct damon_target *t; |
1311 | struct damon_region *r, *next; | |
b9a6ac4e SP |
1312 | unsigned int max_nr_accesses = 0; |
1313 | unsigned long sz_limit = 0; | |
2224d848 | 1314 | |
42e4cef5 | 1315 | pr_debug("kdamond (%d) starts\n", current->pid); |
2224d848 | 1316 | |
f7d911c3 SP |
1317 | if (ctx->ops.init) |
1318 | ctx->ops.init(ctx); | |
2224d848 | 1319 | if (ctx->callback.before_start && ctx->callback.before_start(ctx)) |
29454cf6 | 1320 | goto done; |
2224d848 | 1321 | |
b9a6ac4e SP |
1322 | sz_limit = damon_region_sz_limit(ctx); |
1323 | ||
29454cf6 KX |
1324 | while (!kdamond_need_stop(ctx)) { |
1325 | if (kdamond_wait_activation(ctx)) | |
1326 | break; | |
ee801b7d | 1327 | |
f7d911c3 SP |
1328 | if (ctx->ops.prepare_access_checks) |
1329 | ctx->ops.prepare_access_checks(ctx); | |
2224d848 | 1330 | if (ctx->callback.after_sampling && |
29454cf6 KX |
1331 | ctx->callback.after_sampling(ctx)) |
1332 | break; | |
2224d848 | 1333 | |
cbeaa77b | 1334 | kdamond_usleep(ctx->attrs.sample_interval); |
2224d848 | 1335 | |
f7d911c3 SP |
1336 | if (ctx->ops.check_accesses) |
1337 | max_nr_accesses = ctx->ops.check_accesses(ctx); | |
2224d848 SP |
1338 | |
1339 | if (kdamond_aggregate_interval_passed(ctx)) { | |
b9a6ac4e SP |
1340 | kdamond_merge_regions(ctx, |
1341 | max_nr_accesses / 10, | |
1342 | sz_limit); | |
2224d848 | 1343 | if (ctx->callback.after_aggregation && |
29454cf6 KX |
1344 | ctx->callback.after_aggregation(ctx)) |
1345 | break; | |
64517d6e HY |
1346 | if (!list_empty(&ctx->schemes)) |
1347 | kdamond_apply_schemes(ctx); | |
f23b8eee | 1348 | kdamond_reset_aggregated(ctx); |
b9a6ac4e | 1349 | kdamond_split_regions(ctx); |
f7d911c3 SP |
1350 | if (ctx->ops.reset_aggregated) |
1351 | ctx->ops.reset_aggregated(ctx); | |
2224d848 SP |
1352 | } |
1353 | ||
f7d911c3 SP |
1354 | if (kdamond_need_update_operations(ctx)) { |
1355 | if (ctx->ops.update) | |
1356 | ctx->ops.update(ctx); | |
b9a6ac4e | 1357 | sz_limit = damon_region_sz_limit(ctx); |
2224d848 SP |
1358 | } |
1359 | } | |
29454cf6 | 1360 | done: |
f23b8eee SP |
1361 | damon_for_each_target(t, ctx) { |
1362 | damon_for_each_region_safe(r, next, t) | |
b9a6ac4e | 1363 | damon_destroy_region(r, t); |
f23b8eee | 1364 | } |
2224d848 | 1365 | |
0f91d133 CD |
1366 | if (ctx->callback.before_terminate) |
1367 | ctx->callback.before_terminate(ctx); | |
f7d911c3 SP |
1368 | if (ctx->ops.cleanup) |
1369 | ctx->ops.cleanup(ctx); | |
2224d848 | 1370 | |
42e4cef5 | 1371 | pr_debug("kdamond (%d) finishes\n", current->pid); |
2224d848 SP |
1372 | mutex_lock(&ctx->kdamond_lock); |
1373 | ctx->kdamond = NULL; | |
1374 | mutex_unlock(&ctx->kdamond_lock); | |
1375 | ||
1376 | mutex_lock(&damon_lock); | |
1377 | nr_running_ctxs--; | |
8b9b0d33 SP |
1378 | if (!nr_running_ctxs && running_exclusive_ctxs) |
1379 | running_exclusive_ctxs = false; | |
2224d848 SP |
1380 | mutex_unlock(&damon_lock); |
1381 | ||
5f7fe2b9 | 1382 | return 0; |
2224d848 | 1383 | } |
17ccae8b | 1384 | |
0d83b2d8 XH |
1385 | /* |
1386 | * struct damon_system_ram_region - System RAM resource address region of | |
1387 | * [@start, @end). | |
1388 | * @start: Start address of the region (inclusive). | |
1389 | * @end: End address of the region (exclusive). | |
1390 | */ | |
1391 | struct damon_system_ram_region { | |
1392 | unsigned long start; | |
1393 | unsigned long end; | |
1394 | }; | |
1395 | ||
1396 | static int walk_system_ram(struct resource *res, void *arg) | |
1397 | { | |
1398 | struct damon_system_ram_region *a = arg; | |
1399 | ||
1400 | if (a->end - a->start < resource_size(res)) { | |
1401 | a->start = res->start; | |
1402 | a->end = res->end; | |
1403 | } | |
1404 | return 0; | |
1405 | } | |
1406 | ||
1407 | /* | |
1408 | * Find biggest 'System RAM' resource and store its start and end address in | |
1409 | * @start and @end, respectively. If no System RAM is found, returns false. | |
1410 | */ | |
233f0b31 KX |
1411 | static bool damon_find_biggest_system_ram(unsigned long *start, |
1412 | unsigned long *end) | |
0d83b2d8 XH |
1413 | |
1414 | { | |
1415 | struct damon_system_ram_region arg = {}; | |
1416 | ||
1417 | walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram); | |
1418 | if (arg.end <= arg.start) | |
1419 | return false; | |
1420 | ||
1421 | *start = arg.start; | |
1422 | *end = arg.end; | |
1423 | return true; | |
1424 | } | |
1425 | ||
233f0b31 KX |
1426 | /** |
1427 | * damon_set_region_biggest_system_ram_default() - Set the region of the given | |
1428 | * monitoring target as requested, or biggest 'System RAM'. | |
1429 | * @t: The monitoring target to set the region. | |
1430 | * @start: The pointer to the start address of the region. | |
1431 | * @end: The pointer to the end address of the region. | |
1432 | * | |
1433 | * This function sets the region of @t as requested by @start and @end. If the | |
1434 | * values of @start and @end are zero, however, this function finds the biggest | |
1435 | * 'System RAM' resource and sets the region to cover the resource. In the | |
1436 | * latter case, this function saves the start and end addresses of the resource | |
1437 | * in @start and @end, respectively. | |
1438 | * | |
1439 | * Return: 0 on success, negative error code otherwise. | |
1440 | */ | |
1441 | int damon_set_region_biggest_system_ram_default(struct damon_target *t, | |
1442 | unsigned long *start, unsigned long *end) | |
1443 | { | |
1444 | struct damon_addr_range addr_range; | |
1445 | ||
1446 | if (*start > *end) | |
1447 | return -EINVAL; | |
1448 | ||
1449 | if (!*start && !*end && | |
1450 | !damon_find_biggest_system_ram(start, end)) | |
1451 | return -EINVAL; | |
1452 | ||
1453 | addr_range.start = *start; | |
1454 | addr_range.end = *end; | |
1455 | return damon_set_regions(t, &addr_range, 1); | |
1456 | } | |
1457 | ||
a1870944 DL |
1458 | static int __init damon_init(void) |
1459 | { | |
1460 | damon_region_cache = KMEM_CACHE(damon_region, 0); | |
1461 | if (unlikely(!damon_region_cache)) { | |
1462 | pr_err("creating damon_region_cache fails\n"); | |
1463 | return -ENOMEM; | |
1464 | } | |
1465 | ||
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | subsys_initcall(damon_init); | |
1470 | ||
17ccae8b | 1471 | #include "core-test.h" |