Commit | Line | Data |
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2224d848 SP |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Data Access Monitor | |
4 | * | |
6ad59a38 | 5 | * Author: SeongJae Park <sj@kernel.org> |
2224d848 SP |
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; | |
80333828 | 131 | region->nr_accesses_bp = 0; |
f23b8eee SP |
132 | INIT_LIST_HEAD(®ion->list); |
133 | ||
fda504fa SP |
134 | region->age = 0; |
135 | region->last_nr_accesses = 0; | |
136 | ||
f23b8eee SP |
137 | return region; |
138 | } | |
139 | ||
f23b8eee SP |
140 | void damon_add_region(struct damon_region *r, struct damon_target *t) |
141 | { | |
142 | list_add_tail(&r->list, &t->regions_list); | |
b9a6ac4e | 143 | t->nr_regions++; |
f23b8eee SP |
144 | } |
145 | ||
b9a6ac4e | 146 | static void damon_del_region(struct damon_region *r, struct damon_target *t) |
f23b8eee SP |
147 | { |
148 | list_del(&r->list); | |
b9a6ac4e | 149 | t->nr_regions--; |
f23b8eee SP |
150 | } |
151 | ||
152 | static void damon_free_region(struct damon_region *r) | |
153 | { | |
a1870944 | 154 | kmem_cache_free(damon_region_cache, r); |
f23b8eee SP |
155 | } |
156 | ||
b9a6ac4e | 157 | void damon_destroy_region(struct damon_region *r, struct damon_target *t) |
f23b8eee | 158 | { |
b9a6ac4e | 159 | damon_del_region(r, t); |
f23b8eee SP |
160 | damon_free_region(r); |
161 | } | |
162 | ||
d0723bc0 SP |
163 | /* |
164 | * Check whether a region is intersecting an address range | |
165 | * | |
166 | * Returns true if it is. | |
167 | */ | |
168 | static bool damon_intersect(struct damon_region *r, | |
169 | struct damon_addr_range *re) | |
170 | { | |
171 | return !(r->ar.end <= re->start || re->end <= r->ar.start); | |
172 | } | |
173 | ||
9c950c22 SP |
174 | /* |
175 | * Fill holes in regions with new regions. | |
176 | */ | |
177 | static int damon_fill_regions_holes(struct damon_region *first, | |
178 | struct damon_region *last, struct damon_target *t) | |
179 | { | |
180 | struct damon_region *r = first; | |
181 | ||
182 | damon_for_each_region_from(r, t) { | |
183 | struct damon_region *next, *newr; | |
184 | ||
185 | if (r == last) | |
186 | break; | |
187 | next = damon_next_region(r); | |
188 | if (r->ar.end != next->ar.start) { | |
189 | newr = damon_new_region(r->ar.end, next->ar.start); | |
190 | if (!newr) | |
191 | return -ENOMEM; | |
192 | damon_insert_region(newr, r, next, t); | |
193 | } | |
194 | } | |
195 | return 0; | |
196 | } | |
197 | ||
d0723bc0 SP |
198 | /* |
199 | * damon_set_regions() - Set regions of a target for given address ranges. | |
200 | * @t: the given target. | |
201 | * @ranges: array of new monitoring target ranges. | |
202 | * @nr_ranges: length of @ranges. | |
203 | * | |
204 | * This function adds new regions to, or modify existing regions of a | |
205 | * monitoring target to fit in specific ranges. | |
206 | * | |
207 | * Return: 0 if success, or negative error code otherwise. | |
208 | */ | |
209 | int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, | |
210 | unsigned int nr_ranges) | |
211 | { | |
212 | struct damon_region *r, *next; | |
213 | unsigned int i; | |
9c950c22 | 214 | int err; |
d0723bc0 SP |
215 | |
216 | /* Remove regions which are not in the new ranges */ | |
217 | damon_for_each_region_safe(r, next, t) { | |
218 | for (i = 0; i < nr_ranges; i++) { | |
219 | if (damon_intersect(r, &ranges[i])) | |
220 | break; | |
221 | } | |
222 | if (i == nr_ranges) | |
223 | damon_destroy_region(r, t); | |
224 | } | |
225 | ||
36001cba | 226 | r = damon_first_region(t); |
d0723bc0 SP |
227 | /* Add new regions or resize existing regions to fit in the ranges */ |
228 | for (i = 0; i < nr_ranges; i++) { | |
229 | struct damon_region *first = NULL, *last, *newr; | |
230 | struct damon_addr_range *range; | |
231 | ||
232 | range = &ranges[i]; | |
233 | /* Get the first/last regions intersecting with the range */ | |
36001cba | 234 | damon_for_each_region_from(r, t) { |
d0723bc0 SP |
235 | if (damon_intersect(r, range)) { |
236 | if (!first) | |
237 | first = r; | |
238 | last = r; | |
239 | } | |
240 | if (r->ar.start >= range->end) | |
241 | break; | |
242 | } | |
243 | if (!first) { | |
244 | /* no region intersects with this range */ | |
245 | newr = damon_new_region( | |
246 | ALIGN_DOWN(range->start, | |
247 | DAMON_MIN_REGION), | |
248 | ALIGN(range->end, DAMON_MIN_REGION)); | |
249 | if (!newr) | |
250 | return -ENOMEM; | |
251 | damon_insert_region(newr, damon_prev_region(r), r, t); | |
252 | } else { | |
253 | /* resize intersecting regions to fit in this range */ | |
254 | first->ar.start = ALIGN_DOWN(range->start, | |
255 | DAMON_MIN_REGION); | |
256 | last->ar.end = ALIGN(range->end, DAMON_MIN_REGION); | |
9c950c22 SP |
257 | |
258 | /* fill possible holes in the range */ | |
259 | err = damon_fill_regions_holes(first, last, t); | |
260 | if (err) | |
261 | return err; | |
d0723bc0 SP |
262 | } |
263 | } | |
264 | return 0; | |
265 | } | |
266 | ||
98def236 SP |
267 | struct damos_filter *damos_new_filter(enum damos_filter_type type, |
268 | bool matching) | |
269 | { | |
270 | struct damos_filter *filter; | |
271 | ||
272 | filter = kmalloc(sizeof(*filter), GFP_KERNEL); | |
273 | if (!filter) | |
274 | return NULL; | |
275 | filter->type = type; | |
276 | filter->matching = matching; | |
5f1fc67f | 277 | INIT_LIST_HEAD(&filter->list); |
98def236 SP |
278 | return filter; |
279 | } | |
280 | ||
281 | void damos_add_filter(struct damos *s, struct damos_filter *f) | |
282 | { | |
283 | list_add_tail(&f->list, &s->filters); | |
284 | } | |
285 | ||
286 | static void damos_del_filter(struct damos_filter *f) | |
287 | { | |
288 | list_del(&f->list); | |
289 | } | |
290 | ||
291 | static void damos_free_filter(struct damos_filter *f) | |
292 | { | |
293 | kfree(f); | |
294 | } | |
295 | ||
296 | void damos_destroy_filter(struct damos_filter *f) | |
297 | { | |
298 | damos_del_filter(f); | |
299 | damos_free_filter(f); | |
300 | } | |
301 | ||
70e0c1d1 SP |
302 | /* initialize private fields of damos_quota and return the pointer */ |
303 | static struct damos_quota *damos_quota_init_priv(struct damos_quota *quota) | |
304 | { | |
305 | quota->total_charged_sz = 0; | |
306 | quota->total_charged_ns = 0; | |
307 | quota->esz = 0; | |
308 | quota->charged_sz = 0; | |
309 | quota->charged_from = 0; | |
310 | quota->charge_target_from = NULL; | |
311 | quota->charge_addr_from = 0; | |
312 | return quota; | |
313 | } | |
314 | ||
f5a79d7c | 315 | struct damos *damon_new_scheme(struct damos_access_pattern *pattern, |
42f994b7 SP |
316 | enum damos_action action, |
317 | unsigned long apply_interval_us, | |
318 | struct damos_quota *quota, | |
f5a79d7c | 319 | struct damos_watermarks *wmarks) |
1f366e42 SP |
320 | { |
321 | struct damos *scheme; | |
322 | ||
323 | scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); | |
324 | if (!scheme) | |
325 | return NULL; | |
02f17037 | 326 | scheme->pattern = *pattern; |
1f366e42 | 327 | scheme->action = action; |
42f994b7 SP |
328 | scheme->apply_interval_us = apply_interval_us; |
329 | /* | |
330 | * next_apply_sis will be set when kdamond starts. While kdamond is | |
331 | * running, it will also updated when it is added to the DAMON context, | |
332 | * or damon_attrs are updated. | |
333 | */ | |
334 | scheme->next_apply_sis = 0; | |
98def236 | 335 | INIT_LIST_HEAD(&scheme->filters); |
0e92c2ee | 336 | scheme->stat = (struct damos_stat){}; |
1f366e42 SP |
337 | INIT_LIST_HEAD(&scheme->list); |
338 | ||
70e0c1d1 | 339 | scheme->quota = *(damos_quota_init_priv(quota)); |
2b8a248d | 340 | |
02f17037 | 341 | scheme->wmarks = *wmarks; |
ee801b7d SP |
342 | scheme->wmarks.activated = true; |
343 | ||
1f366e42 SP |
344 | return scheme; |
345 | } | |
346 | ||
42f994b7 SP |
347 | static void damos_set_next_apply_sis(struct damos *s, struct damon_ctx *ctx) |
348 | { | |
349 | unsigned long sample_interval = ctx->attrs.sample_interval ? | |
350 | ctx->attrs.sample_interval : 1; | |
351 | unsigned long apply_interval = s->apply_interval_us ? | |
352 | s->apply_interval_us : ctx->attrs.aggr_interval; | |
353 | ||
354 | s->next_apply_sis = ctx->passed_sample_intervals + | |
355 | apply_interval / sample_interval; | |
356 | } | |
357 | ||
1f366e42 SP |
358 | void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) |
359 | { | |
360 | list_add_tail(&s->list, &ctx->schemes); | |
42f994b7 | 361 | damos_set_next_apply_sis(s, ctx); |
1f366e42 SP |
362 | } |
363 | ||
364 | static void damon_del_scheme(struct damos *s) | |
365 | { | |
366 | list_del(&s->list); | |
367 | } | |
368 | ||
369 | static void damon_free_scheme(struct damos *s) | |
370 | { | |
371 | kfree(s); | |
372 | } | |
373 | ||
374 | void damon_destroy_scheme(struct damos *s) | |
375 | { | |
98def236 SP |
376 | struct damos_filter *f, *next; |
377 | ||
378 | damos_for_each_filter_safe(f, next, s) | |
379 | damos_destroy_filter(f); | |
1f366e42 SP |
380 | damon_del_scheme(s); |
381 | damon_free_scheme(s); | |
382 | } | |
383 | ||
f23b8eee SP |
384 | /* |
385 | * Construct a damon_target struct | |
386 | * | |
387 | * Returns the pointer to the new struct if success, or NULL otherwise | |
388 | */ | |
1971bd63 | 389 | struct damon_target *damon_new_target(void) |
f23b8eee SP |
390 | { |
391 | struct damon_target *t; | |
392 | ||
393 | t = kmalloc(sizeof(*t), GFP_KERNEL); | |
394 | if (!t) | |
395 | return NULL; | |
396 | ||
1971bd63 | 397 | t->pid = NULL; |
b9a6ac4e | 398 | t->nr_regions = 0; |
f23b8eee | 399 | INIT_LIST_HEAD(&t->regions_list); |
b1f44cda | 400 | INIT_LIST_HEAD(&t->list); |
f23b8eee SP |
401 | |
402 | return t; | |
403 | } | |
404 | ||
405 | void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) | |
406 | { | |
b9a6ac4e | 407 | list_add_tail(&t->list, &ctx->adaptive_targets); |
f23b8eee SP |
408 | } |
409 | ||
b5ca3e83 XH |
410 | bool damon_targets_empty(struct damon_ctx *ctx) |
411 | { | |
412 | return list_empty(&ctx->adaptive_targets); | |
413 | } | |
414 | ||
f23b8eee SP |
415 | static void damon_del_target(struct damon_target *t) |
416 | { | |
417 | list_del(&t->list); | |
418 | } | |
419 | ||
420 | void damon_free_target(struct damon_target *t) | |
421 | { | |
422 | struct damon_region *r, *next; | |
423 | ||
424 | damon_for_each_region_safe(r, next, t) | |
425 | damon_free_region(r); | |
426 | kfree(t); | |
427 | } | |
428 | ||
429 | void damon_destroy_target(struct damon_target *t) | |
430 | { | |
431 | damon_del_target(t); | |
432 | damon_free_target(t); | |
433 | } | |
434 | ||
b9a6ac4e SP |
435 | unsigned int damon_nr_regions(struct damon_target *t) |
436 | { | |
437 | return t->nr_regions; | |
438 | } | |
439 | ||
2224d848 SP |
440 | struct damon_ctx *damon_new_ctx(void) |
441 | { | |
442 | struct damon_ctx *ctx; | |
443 | ||
444 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); | |
445 | if (!ctx) | |
446 | return NULL; | |
447 | ||
6376a824 SP |
448 | init_completion(&ctx->kdamond_started); |
449 | ||
cbeaa77b SP |
450 | ctx->attrs.sample_interval = 5 * 1000; |
451 | ctx->attrs.aggr_interval = 100 * 1000; | |
452 | ctx->attrs.ops_update_interval = 60 * 1000 * 1000; | |
2224d848 | 453 | |
4472edf6 SP |
454 | ctx->passed_sample_intervals = 0; |
455 | /* These will be set from kdamond_init_intervals_sis() */ | |
456 | ctx->next_aggregation_sis = 0; | |
457 | ctx->next_ops_update_sis = 0; | |
2224d848 SP |
458 | |
459 | mutex_init(&ctx->kdamond_lock); | |
460 | ||
cbeaa77b SP |
461 | ctx->attrs.min_nr_regions = 10; |
462 | ctx->attrs.max_nr_regions = 1000; | |
b9a6ac4e SP |
463 | |
464 | INIT_LIST_HEAD(&ctx->adaptive_targets); | |
1f366e42 | 465 | INIT_LIST_HEAD(&ctx->schemes); |
2224d848 SP |
466 | |
467 | return ctx; | |
468 | } | |
469 | ||
f23b8eee | 470 | static void damon_destroy_targets(struct damon_ctx *ctx) |
2224d848 | 471 | { |
f23b8eee SP |
472 | struct damon_target *t, *next_t; |
473 | ||
f7d911c3 SP |
474 | if (ctx->ops.cleanup) { |
475 | ctx->ops.cleanup(ctx); | |
f23b8eee SP |
476 | return; |
477 | } | |
478 | ||
479 | damon_for_each_target_safe(t, next_t, ctx) | |
480 | damon_destroy_target(t); | |
481 | } | |
482 | ||
483 | void damon_destroy_ctx(struct damon_ctx *ctx) | |
484 | { | |
1f366e42 SP |
485 | struct damos *s, *next_s; |
486 | ||
f23b8eee | 487 | damon_destroy_targets(ctx); |
1f366e42 SP |
488 | |
489 | damon_for_each_scheme_safe(s, next_s, ctx) | |
490 | damon_destroy_scheme(s); | |
491 | ||
2224d848 SP |
492 | kfree(ctx); |
493 | } | |
494 | ||
2f5bef5a SP |
495 | static unsigned int damon_age_for_new_attrs(unsigned int age, |
496 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
497 | { | |
498 | return age * old_attrs->aggr_interval / new_attrs->aggr_interval; | |
499 | } | |
500 | ||
501 | /* convert access ratio in bp (per 10,000) to nr_accesses */ | |
502 | static unsigned int damon_accesses_bp_to_nr_accesses( | |
503 | unsigned int accesses_bp, struct damon_attrs *attrs) | |
504 | { | |
d35963bf | 505 | return accesses_bp * damon_max_nr_accesses(attrs) / 10000; |
2f5bef5a SP |
506 | } |
507 | ||
508 | /* convert nr_accesses to access ratio in bp (per 10,000) */ | |
509 | static unsigned int damon_nr_accesses_to_accesses_bp( | |
510 | unsigned int nr_accesses, struct damon_attrs *attrs) | |
511 | { | |
d35963bf | 512 | return nr_accesses * 10000 / damon_max_nr_accesses(attrs); |
2f5bef5a SP |
513 | } |
514 | ||
515 | static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses, | |
516 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
517 | { | |
518 | return damon_accesses_bp_to_nr_accesses( | |
519 | damon_nr_accesses_to_accesses_bp( | |
520 | nr_accesses, old_attrs), | |
521 | new_attrs); | |
522 | } | |
523 | ||
524 | static void damon_update_monitoring_result(struct damon_region *r, | |
525 | struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) | |
526 | { | |
527 | r->nr_accesses = damon_nr_accesses_for_new_attrs(r->nr_accesses, | |
528 | old_attrs, new_attrs); | |
80333828 | 529 | r->nr_accesses_bp = r->nr_accesses * 10000; |
2f5bef5a SP |
530 | r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs); |
531 | } | |
532 | ||
533 | /* | |
534 | * region->nr_accesses is the number of sampling intervals in the last | |
535 | * aggregation interval that access to the region has found, and region->age is | |
536 | * the number of aggregation intervals that its access pattern has maintained. | |
537 | * For the reason, the real meaning of the two fields depend on current | |
538 | * sampling interval and aggregation interval. This function updates | |
539 | * ->nr_accesses and ->age of given damon_ctx's regions for new damon_attrs. | |
540 | */ | |
541 | static void damon_update_monitoring_results(struct damon_ctx *ctx, | |
542 | struct damon_attrs *new_attrs) | |
543 | { | |
544 | struct damon_attrs *old_attrs = &ctx->attrs; | |
545 | struct damon_target *t; | |
546 | struct damon_region *r; | |
547 | ||
548 | /* if any interval is zero, simply forgive conversion */ | |
549 | if (!old_attrs->sample_interval || !old_attrs->aggr_interval || | |
550 | !new_attrs->sample_interval || | |
551 | !new_attrs->aggr_interval) | |
552 | return; | |
553 | ||
554 | damon_for_each_target(t, ctx) | |
555 | damon_for_each_region(r, t) | |
556 | damon_update_monitoring_result( | |
557 | r, old_attrs, new_attrs); | |
558 | } | |
559 | ||
2224d848 SP |
560 | /** |
561 | * damon_set_attrs() - Set attributes for the monitoring. | |
562 | * @ctx: monitoring context | |
bead3b00 | 563 | * @attrs: monitoring attributes |
2224d848 | 564 | * |
27e68c4b SP |
565 | * This function should be called while the kdamond is not running, or an |
566 | * access check results aggregation is not ongoing (e.g., from | |
567 | * &struct damon_callback->after_aggregation or | |
568 | * &struct damon_callback->after_wmarks_check callbacks). | |
569 | * | |
2224d848 SP |
570 | * Every time interval is in micro-seconds. |
571 | * | |
572 | * Return: 0 on success, negative error code otherwise. | |
573 | */ | |
bead3b00 | 574 | int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs) |
2224d848 | 575 | { |
4472edf6 SP |
576 | unsigned long sample_interval = attrs->sample_interval ? |
577 | attrs->sample_interval : 1; | |
42f994b7 | 578 | struct damos *s; |
4472edf6 | 579 | |
bead3b00 | 580 | if (attrs->min_nr_regions < 3) |
b9a6ac4e | 581 | return -EINVAL; |
bead3b00 | 582 | if (attrs->min_nr_regions > attrs->max_nr_regions) |
b9a6ac4e | 583 | return -EINVAL; |
5ff6e2ff KW |
584 | if (attrs->sample_interval > attrs->aggr_interval) |
585 | return -EINVAL; | |
b9a6ac4e | 586 | |
4472edf6 SP |
587 | ctx->next_aggregation_sis = ctx->passed_sample_intervals + |
588 | attrs->aggr_interval / sample_interval; | |
589 | ctx->next_ops_update_sis = ctx->passed_sample_intervals + | |
590 | attrs->ops_update_interval / sample_interval; | |
591 | ||
2f5bef5a | 592 | damon_update_monitoring_results(ctx, attrs); |
bead3b00 | 593 | ctx->attrs = *attrs; |
42f994b7 SP |
594 | |
595 | damon_for_each_scheme(s, ctx) | |
596 | damos_set_next_apply_sis(s, ctx); | |
597 | ||
2224d848 SP |
598 | return 0; |
599 | } | |
600 | ||
1f366e42 SP |
601 | /** |
602 | * damon_set_schemes() - Set data access monitoring based operation schemes. | |
603 | * @ctx: monitoring context | |
604 | * @schemes: array of the schemes | |
605 | * @nr_schemes: number of entries in @schemes | |
606 | * | |
607 | * This function should not be called while the kdamond of the context is | |
608 | * running. | |
1f366e42 | 609 | */ |
cc713520 | 610 | void damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, |
1f366e42 SP |
611 | ssize_t nr_schemes) |
612 | { | |
613 | struct damos *s, *next; | |
614 | ssize_t i; | |
615 | ||
616 | damon_for_each_scheme_safe(s, next, ctx) | |
617 | damon_destroy_scheme(s); | |
618 | for (i = 0; i < nr_schemes; i++) | |
619 | damon_add_scheme(ctx, schemes[i]); | |
1f366e42 SP |
620 | } |
621 | ||
4bc05954 SP |
622 | /** |
623 | * damon_nr_running_ctxs() - Return number of currently running contexts. | |
624 | */ | |
625 | int damon_nr_running_ctxs(void) | |
626 | { | |
627 | int nr_ctxs; | |
628 | ||
629 | mutex_lock(&damon_lock); | |
630 | nr_ctxs = nr_running_ctxs; | |
631 | mutex_unlock(&damon_lock); | |
632 | ||
633 | return nr_ctxs; | |
634 | } | |
635 | ||
b9a6ac4e SP |
636 | /* Returns the size upper limit for each monitoring region */ |
637 | static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) | |
638 | { | |
639 | struct damon_target *t; | |
640 | struct damon_region *r; | |
641 | unsigned long sz = 0; | |
642 | ||
643 | damon_for_each_target(t, ctx) { | |
644 | damon_for_each_region(r, t) | |
ab63f63f | 645 | sz += damon_sz_region(r); |
b9a6ac4e SP |
646 | } |
647 | ||
cbeaa77b SP |
648 | if (ctx->attrs.min_nr_regions) |
649 | sz /= ctx->attrs.min_nr_regions; | |
b9a6ac4e SP |
650 | if (sz < DAMON_MIN_REGION) |
651 | sz = DAMON_MIN_REGION; | |
652 | ||
653 | return sz; | |
654 | } | |
655 | ||
2224d848 SP |
656 | static int kdamond_fn(void *data); |
657 | ||
658 | /* | |
659 | * __damon_start() - Starts monitoring with given context. | |
660 | * @ctx: monitoring context | |
661 | * | |
662 | * This function should be called while damon_lock is hold. | |
663 | * | |
664 | * Return: 0 on success, negative error code otherwise. | |
665 | */ | |
666 | static int __damon_start(struct damon_ctx *ctx) | |
667 | { | |
668 | int err = -EBUSY; | |
669 | ||
670 | mutex_lock(&ctx->kdamond_lock); | |
671 | if (!ctx->kdamond) { | |
672 | err = 0; | |
6376a824 | 673 | reinit_completion(&ctx->kdamond_started); |
2224d848 SP |
674 | ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", |
675 | nr_running_ctxs); | |
676 | if (IS_ERR(ctx->kdamond)) { | |
677 | err = PTR_ERR(ctx->kdamond); | |
7ec1992b | 678 | ctx->kdamond = NULL; |
6376a824 SP |
679 | } else { |
680 | wait_for_completion(&ctx->kdamond_started); | |
2224d848 SP |
681 | } |
682 | } | |
683 | mutex_unlock(&ctx->kdamond_lock); | |
684 | ||
685 | return err; | |
686 | } | |
687 | ||
688 | /** | |
689 | * damon_start() - Starts the monitorings for a given group of contexts. | |
690 | * @ctxs: an array of the pointers for contexts to start monitoring | |
691 | * @nr_ctxs: size of @ctxs | |
8b9b0d33 | 692 | * @exclusive: exclusiveness of this contexts group |
2224d848 SP |
693 | * |
694 | * This function starts a group of monitoring threads for a group of monitoring | |
695 | * contexts. One thread per each context is created and run in parallel. The | |
8b9b0d33 SP |
696 | * caller should handle synchronization between the threads by itself. If |
697 | * @exclusive is true and a group of threads that created by other | |
698 | * 'damon_start()' call is currently running, this function does nothing but | |
699 | * returns -EBUSY. | |
2224d848 SP |
700 | * |
701 | * Return: 0 on success, negative error code otherwise. | |
702 | */ | |
8b9b0d33 | 703 | int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive) |
2224d848 SP |
704 | { |
705 | int i; | |
706 | int err = 0; | |
707 | ||
708 | mutex_lock(&damon_lock); | |
8b9b0d33 SP |
709 | if ((exclusive && nr_running_ctxs) || |
710 | (!exclusive && running_exclusive_ctxs)) { | |
2224d848 SP |
711 | mutex_unlock(&damon_lock); |
712 | return -EBUSY; | |
713 | } | |
714 | ||
715 | for (i = 0; i < nr_ctxs; i++) { | |
716 | err = __damon_start(ctxs[i]); | |
717 | if (err) | |
718 | break; | |
719 | nr_running_ctxs++; | |
720 | } | |
8b9b0d33 SP |
721 | if (exclusive && nr_running_ctxs) |
722 | running_exclusive_ctxs = true; | |
2224d848 SP |
723 | mutex_unlock(&damon_lock); |
724 | ||
725 | return err; | |
726 | } | |
727 | ||
728 | /* | |
8b9b0d33 | 729 | * __damon_stop() - Stops monitoring of a given context. |
2224d848 SP |
730 | * @ctx: monitoring context |
731 | * | |
732 | * Return: 0 on success, negative error code otherwise. | |
733 | */ | |
734 | static int __damon_stop(struct damon_ctx *ctx) | |
735 | { | |
0f91d133 CD |
736 | struct task_struct *tsk; |
737 | ||
2224d848 | 738 | mutex_lock(&ctx->kdamond_lock); |
0f91d133 CD |
739 | tsk = ctx->kdamond; |
740 | if (tsk) { | |
741 | get_task_struct(tsk); | |
2224d848 | 742 | mutex_unlock(&ctx->kdamond_lock); |
6309727e | 743 | kthread_stop_put(tsk); |
2224d848 SP |
744 | return 0; |
745 | } | |
746 | mutex_unlock(&ctx->kdamond_lock); | |
747 | ||
748 | return -EPERM; | |
749 | } | |
750 | ||
751 | /** | |
752 | * damon_stop() - Stops the monitorings for a given group of contexts. | |
753 | * @ctxs: an array of the pointers for contexts to stop monitoring | |
754 | * @nr_ctxs: size of @ctxs | |
755 | * | |
756 | * Return: 0 on success, negative error code otherwise. | |
757 | */ | |
758 | int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) | |
759 | { | |
760 | int i, err = 0; | |
761 | ||
762 | for (i = 0; i < nr_ctxs; i++) { | |
763 | /* nr_running_ctxs is decremented in kdamond_fn */ | |
764 | err = __damon_stop(ctxs[i]); | |
765 | if (err) | |
8b9b0d33 | 766 | break; |
2224d848 | 767 | } |
2224d848 SP |
768 | return err; |
769 | } | |
770 | ||
f23b8eee SP |
771 | /* |
772 | * Reset the aggregated monitoring results ('nr_accesses' of each region). | |
773 | */ | |
774 | static void kdamond_reset_aggregated(struct damon_ctx *c) | |
775 | { | |
776 | struct damon_target *t; | |
76fd0285 | 777 | unsigned int ti = 0; /* target's index */ |
f23b8eee SP |
778 | |
779 | damon_for_each_target(t, c) { | |
780 | struct damon_region *r; | |
781 | ||
2fcb9362 | 782 | damon_for_each_region(r, t) { |
2d00946b | 783 | trace_damon_aggregated(ti, r, damon_nr_regions(t)); |
fda504fa | 784 | r->last_nr_accesses = r->nr_accesses; |
f23b8eee | 785 | r->nr_accesses = 0; |
2fcb9362 | 786 | } |
76fd0285 | 787 | ti++; |
f23b8eee SP |
788 | } |
789 | } | |
790 | ||
4ed98243 KX |
791 | static void damon_split_region_at(struct damon_target *t, |
792 | struct damon_region *r, unsigned long sz_r); | |
2b8a248d | 793 | |
38683e00 SP |
794 | static bool __damos_valid_target(struct damon_region *r, struct damos *s) |
795 | { | |
796 | unsigned long sz; | |
affa87c7 | 797 | unsigned int nr_accesses = r->nr_accesses_bp / 10000; |
38683e00 | 798 | |
ab63f63f | 799 | sz = damon_sz_region(r); |
f5a79d7c YD |
800 | return s->pattern.min_sz_region <= sz && |
801 | sz <= s->pattern.max_sz_region && | |
affa87c7 SP |
802 | s->pattern.min_nr_accesses <= nr_accesses && |
803 | nr_accesses <= s->pattern.max_nr_accesses && | |
f5a79d7c YD |
804 | s->pattern.min_age_region <= r->age && |
805 | r->age <= s->pattern.max_age_region; | |
38683e00 SP |
806 | } |
807 | ||
808 | static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, | |
809 | struct damon_region *r, struct damos *s) | |
810 | { | |
811 | bool ret = __damos_valid_target(r, s); | |
812 | ||
f7d911c3 | 813 | if (!ret || !s->quota.esz || !c->ops.get_scheme_score) |
38683e00 SP |
814 | return ret; |
815 | ||
f7d911c3 | 816 | return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; |
38683e00 SP |
817 | } |
818 | ||
2ea34989 SP |
819 | /* |
820 | * damos_skip_charged_region() - Check if the given region or starting part of | |
821 | * it is already charged for the DAMOS quota. | |
822 | * @t: The target of the region. | |
823 | * @rp: The pointer to the region. | |
824 | * @s: The scheme to be applied. | |
825 | * | |
826 | * If a quota of a scheme has exceeded in a quota charge window, the scheme's | |
827 | * action would applied to only a part of the target access pattern fulfilling | |
828 | * regions. To avoid applying the scheme action to only already applied | |
829 | * regions, DAMON skips applying the scheme action to the regions that charged | |
830 | * in the previous charge window. | |
831 | * | |
832 | * This function checks if a given region should be skipped or not for the | |
833 | * reason. If only the starting part of the region has previously charged, | |
834 | * this function splits the region into two so that the second one covers the | |
835 | * area that not charged in the previous charge widnow and saves the second | |
836 | * region in *rp and returns false, so that the caller can apply DAMON action | |
837 | * to the second one. | |
838 | * | |
839 | * Return: true if the region should be entirely skipped, false otherwise. | |
840 | */ | |
841 | static bool damos_skip_charged_region(struct damon_target *t, | |
842 | struct damon_region **rp, struct damos *s) | |
843 | { | |
844 | struct damon_region *r = *rp; | |
845 | struct damos_quota *quota = &s->quota; | |
846 | unsigned long sz_to_skip; | |
847 | ||
848 | /* Skip previously charged regions */ | |
849 | if (quota->charge_target_from) { | |
850 | if (t != quota->charge_target_from) | |
851 | return true; | |
852 | if (r == damon_last_region(t)) { | |
853 | quota->charge_target_from = NULL; | |
854 | quota->charge_addr_from = 0; | |
855 | return true; | |
856 | } | |
857 | if (quota->charge_addr_from && | |
858 | r->ar.end <= quota->charge_addr_from) | |
859 | return true; | |
860 | ||
861 | if (quota->charge_addr_from && r->ar.start < | |
862 | quota->charge_addr_from) { | |
863 | sz_to_skip = ALIGN_DOWN(quota->charge_addr_from - | |
864 | r->ar.start, DAMON_MIN_REGION); | |
865 | if (!sz_to_skip) { | |
866 | if (damon_sz_region(r) <= DAMON_MIN_REGION) | |
867 | return true; | |
868 | sz_to_skip = DAMON_MIN_REGION; | |
869 | } | |
870 | damon_split_region_at(t, r, sz_to_skip); | |
871 | r = damon_next_region(r); | |
872 | *rp = r; | |
873 | } | |
874 | quota->charge_target_from = NULL; | |
875 | quota->charge_addr_from = 0; | |
876 | } | |
877 | return false; | |
878 | } | |
879 | ||
d1cbbf62 SP |
880 | static void damos_update_stat(struct damos *s, |
881 | unsigned long sz_tried, unsigned long sz_applied) | |
882 | { | |
883 | s->stat.nr_tried++; | |
884 | s->stat.sz_tried += sz_tried; | |
885 | if (sz_applied) | |
886 | s->stat.nr_applied++; | |
887 | s->stat.sz_applied += sz_applied; | |
888 | } | |
889 | ||
17e7c724 SP |
890 | static bool __damos_filter_out(struct damon_ctx *ctx, struct damon_target *t, |
891 | struct damon_region *r, struct damos_filter *filter) | |
ab9bda00 SP |
892 | { |
893 | bool matched = false; | |
17e7c724 SP |
894 | struct damon_target *ti; |
895 | int target_idx = 0; | |
ab9bda00 SP |
896 | unsigned long start, end; |
897 | ||
898 | switch (filter->type) { | |
17e7c724 SP |
899 | case DAMOS_FILTER_TYPE_TARGET: |
900 | damon_for_each_target(ti, ctx) { | |
901 | if (ti == t) | |
902 | break; | |
903 | target_idx++; | |
904 | } | |
905 | matched = target_idx == filter->target_idx; | |
906 | break; | |
ab9bda00 SP |
907 | case DAMOS_FILTER_TYPE_ADDR: |
908 | start = ALIGN_DOWN(filter->addr_range.start, DAMON_MIN_REGION); | |
909 | end = ALIGN_DOWN(filter->addr_range.end, DAMON_MIN_REGION); | |
910 | ||
911 | /* inside the range */ | |
912 | if (start <= r->ar.start && r->ar.end <= end) { | |
913 | matched = true; | |
914 | break; | |
915 | } | |
916 | /* outside of the range */ | |
917 | if (r->ar.end <= start || end <= r->ar.start) { | |
918 | matched = false; | |
919 | break; | |
920 | } | |
921 | /* start before the range and overlap */ | |
922 | if (r->ar.start < start) { | |
923 | damon_split_region_at(t, r, start - r->ar.start); | |
924 | matched = false; | |
925 | break; | |
926 | } | |
927 | /* start inside the range */ | |
928 | damon_split_region_at(t, r, end - r->ar.start); | |
929 | matched = true; | |
930 | break; | |
931 | default: | |
13b2a4b2 | 932 | return false; |
ab9bda00 SP |
933 | } |
934 | ||
935 | return matched == filter->matching; | |
936 | } | |
937 | ||
17e7c724 SP |
938 | static bool damos_filter_out(struct damon_ctx *ctx, struct damon_target *t, |
939 | struct damon_region *r, struct damos *s) | |
ab9bda00 SP |
940 | { |
941 | struct damos_filter *filter; | |
942 | ||
943 | damos_for_each_filter(filter, s) { | |
17e7c724 | 944 | if (__damos_filter_out(ctx, t, r, filter)) |
ab9bda00 SP |
945 | return true; |
946 | } | |
947 | return false; | |
948 | } | |
949 | ||
e63a30c5 SP |
950 | static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, |
951 | struct damon_region *r, struct damos *s) | |
952 | { | |
953 | struct damos_quota *quota = &s->quota; | |
954 | unsigned long sz = damon_sz_region(r); | |
955 | struct timespec64 begin, end; | |
956 | unsigned long sz_applied = 0; | |
44467bbb | 957 | int err = 0; |
c603c630 SP |
958 | /* |
959 | * We plan to support multiple context per kdamond, as DAMON sysfs | |
960 | * implies with 'nr_contexts' file. Nevertheless, only single context | |
961 | * per kdamond is supported for now. So, we can simply use '0' context | |
962 | * index here. | |
963 | */ | |
964 | unsigned int cidx = 0; | |
965 | struct damos *siter; /* schemes iterator */ | |
966 | unsigned int sidx = 0; | |
967 | struct damon_target *titer; /* targets iterator */ | |
968 | unsigned int tidx = 0; | |
969 | bool do_trace = false; | |
970 | ||
971 | /* get indices for trace_damos_before_apply() */ | |
972 | if (trace_damos_before_apply_enabled()) { | |
973 | damon_for_each_scheme(siter, c) { | |
974 | if (siter == s) | |
975 | break; | |
976 | sidx++; | |
977 | } | |
978 | damon_for_each_target(titer, c) { | |
979 | if (titer == t) | |
980 | break; | |
981 | tidx++; | |
982 | } | |
983 | do_trace = true; | |
984 | } | |
e63a30c5 SP |
985 | |
986 | if (c->ops.apply_scheme) { | |
987 | if (quota->esz && quota->charged_sz + sz > quota->esz) { | |
988 | sz = ALIGN_DOWN(quota->esz - quota->charged_sz, | |
989 | DAMON_MIN_REGION); | |
990 | if (!sz) | |
991 | goto update_stat; | |
992 | damon_split_region_at(t, r, sz); | |
993 | } | |
17e7c724 | 994 | if (damos_filter_out(c, t, r, s)) |
ab9bda00 | 995 | return; |
e63a30c5 | 996 | ktime_get_coarse_ts64(&begin); |
44467bbb SP |
997 | if (c->callback.before_damos_apply) |
998 | err = c->callback.before_damos_apply(c, t, r, s); | |
c603c630 SP |
999 | if (!err) { |
1000 | trace_damos_before_apply(cidx, sidx, tidx, r, | |
1001 | damon_nr_regions(t), do_trace); | |
44467bbb | 1002 | sz_applied = c->ops.apply_scheme(c, t, r, s); |
c603c630 | 1003 | } |
e63a30c5 SP |
1004 | ktime_get_coarse_ts64(&end); |
1005 | quota->total_charged_ns += timespec64_to_ns(&end) - | |
1006 | timespec64_to_ns(&begin); | |
1007 | quota->charged_sz += sz; | |
1008 | if (quota->esz && quota->charged_sz >= quota->esz) { | |
1009 | quota->charge_target_from = t; | |
1010 | quota->charge_addr_from = r->ar.end + 1; | |
1011 | } | |
1012 | } | |
1013 | if (s->action != DAMOS_STAT) | |
1014 | r->age = 0; | |
1015 | ||
1016 | update_stat: | |
d1cbbf62 | 1017 | damos_update_stat(s, sz, sz_applied); |
e63a30c5 SP |
1018 | } |
1019 | ||
1f366e42 SP |
1020 | static void damon_do_apply_schemes(struct damon_ctx *c, |
1021 | struct damon_target *t, | |
1022 | struct damon_region *r) | |
1023 | { | |
1024 | struct damos *s; | |
1f366e42 SP |
1025 | |
1026 | damon_for_each_scheme(s, c) { | |
2b8a248d | 1027 | struct damos_quota *quota = &s->quota; |
2b8a248d | 1028 | |
e9e3db69 SP |
1029 | if (c->passed_sample_intervals != s->next_apply_sis) |
1030 | continue; | |
1031 | ||
ee801b7d SP |
1032 | if (!s->wmarks.activated) |
1033 | continue; | |
1034 | ||
2b8a248d | 1035 | /* Check the quota */ |
1cd24303 | 1036 | if (quota->esz && quota->charged_sz >= quota->esz) |
2b8a248d SP |
1037 | continue; |
1038 | ||
2ea34989 SP |
1039 | if (damos_skip_charged_region(t, &r, s)) |
1040 | continue; | |
50585192 | 1041 | |
38683e00 | 1042 | if (!damos_valid_target(c, t, r, s)) |
1f366e42 | 1043 | continue; |
2b8a248d | 1044 | |
e63a30c5 | 1045 | damos_apply_scheme(c, t, r, s); |
1f366e42 SP |
1046 | } |
1047 | } | |
1048 | ||
9294a037 SP |
1049 | /* |
1050 | * damon_feed_loop_next_input() - get next input to achieve a target score. | |
1051 | * @last_input The last input. | |
1052 | * @score Current score that made with @last_input. | |
1053 | * | |
1054 | * Calculate next input to achieve the target score, based on the last input | |
1055 | * and current score. Assuming the input and the score are positively | |
1056 | * proportional, calculate how much compensation should be added to or | |
1057 | * subtracted from the last input as a proportion of the last input. Avoid | |
1058 | * next input always being zero by setting it non-zero always. In short form | |
1059 | * (assuming support of float and signed calculations), the algorithm is as | |
1060 | * below. | |
1061 | * | |
1062 | * next_input = max(last_input * ((goal - current) / goal + 1), 1) | |
1063 | * | |
1064 | * For simple implementation, we assume the target score is always 10,000. The | |
1065 | * caller should adjust @score for this. | |
1066 | * | |
1067 | * Returns next input that assumed to achieve the target score. | |
1068 | */ | |
1069 | static unsigned long damon_feed_loop_next_input(unsigned long last_input, | |
1070 | unsigned long score) | |
1071 | { | |
1072 | const unsigned long goal = 10000; | |
1073 | unsigned long score_goal_diff = max(goal, score) - min(goal, score); | |
1074 | unsigned long score_goal_diff_bp = score_goal_diff * 10000 / goal; | |
1075 | unsigned long compensation = last_input * score_goal_diff_bp / 10000; | |
1076 | /* Set minimum input as 10000 to avoid compensation be zero */ | |
1077 | const unsigned long min_input = 10000; | |
1078 | ||
1079 | if (goal > score) | |
1080 | return last_input + compensation; | |
1081 | if (last_input > compensation + min_input) | |
1082 | return last_input - compensation; | |
1083 | return min_input; | |
1084 | } | |
1085 | ||
1086 | /* Shouldn't be called if quota->ms, quota->sz, and quota->get_score unset */ | |
1cd24303 SP |
1087 | static void damos_set_effective_quota(struct damos_quota *quota) |
1088 | { | |
1089 | unsigned long throughput; | |
1090 | unsigned long esz; | |
1091 | ||
9294a037 | 1092 | if (!quota->ms && !quota->get_score) { |
1cd24303 SP |
1093 | quota->esz = quota->sz; |
1094 | return; | |
1095 | } | |
1096 | ||
9294a037 SP |
1097 | if (quota->get_score) { |
1098 | quota->esz_bp = damon_feed_loop_next_input( | |
1099 | max(quota->esz_bp, 10000UL), | |
1100 | quota->get_score(quota->get_score_arg)); | |
1101 | esz = quota->esz_bp / 10000; | |
1102 | } | |
1103 | ||
1104 | if (quota->ms) { | |
1105 | if (quota->total_charged_ns) | |
1106 | throughput = quota->total_charged_sz * 1000000 / | |
1107 | quota->total_charged_ns; | |
1108 | else | |
1109 | throughput = PAGE_SIZE * 1024; | |
1110 | if (quota->get_score) | |
1111 | esz = min(throughput * quota->ms, esz); | |
1112 | else | |
1113 | esz = throughput * quota->ms; | |
1114 | } | |
1cd24303 SP |
1115 | |
1116 | if (quota->sz && quota->sz < esz) | |
1117 | esz = quota->sz; | |
9294a037 | 1118 | |
1cd24303 SP |
1119 | quota->esz = esz; |
1120 | } | |
1121 | ||
898810e5 | 1122 | static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) |
1f366e42 | 1123 | { |
898810e5 | 1124 | struct damos_quota *quota = &s->quota; |
1f366e42 | 1125 | struct damon_target *t; |
898810e5 SP |
1126 | struct damon_region *r; |
1127 | unsigned long cumulated_sz; | |
1128 | unsigned int score, max_score = 0; | |
2b8a248d | 1129 | |
9294a037 | 1130 | if (!quota->ms && !quota->sz && !quota->get_score) |
898810e5 | 1131 | return; |
2b8a248d | 1132 | |
898810e5 SP |
1133 | /* New charge window starts */ |
1134 | if (time_after_eq(jiffies, quota->charged_from + | |
1135 | msecs_to_jiffies(quota->reset_interval))) { | |
1136 | if (quota->esz && quota->charged_sz >= quota->esz) | |
1137 | s->stat.qt_exceeds++; | |
1138 | quota->total_charged_sz += quota->charged_sz; | |
1139 | quota->charged_from = jiffies; | |
1140 | quota->charged_sz = 0; | |
1141 | damos_set_effective_quota(quota); | |
1142 | } | |
ee801b7d | 1143 | |
898810e5 SP |
1144 | if (!c->ops.get_scheme_score) |
1145 | return; | |
2b8a248d | 1146 | |
898810e5 SP |
1147 | /* Fill up the score histogram */ |
1148 | memset(quota->histogram, 0, sizeof(quota->histogram)); | |
1149 | damon_for_each_target(t, c) { | |
1150 | damon_for_each_region(r, t) { | |
1151 | if (!__damos_valid_target(r, s)) | |
1152 | continue; | |
1153 | score = c->ops.get_scheme_score(c, t, r, s); | |
1154 | quota->histogram[score] += damon_sz_region(r); | |
1155 | if (score > max_score) | |
1156 | max_score = score; | |
2b8a248d | 1157 | } |
898810e5 | 1158 | } |
38683e00 | 1159 | |
898810e5 SP |
1160 | /* Set the min score limit */ |
1161 | for (cumulated_sz = 0, score = max_score; ; score--) { | |
1162 | cumulated_sz += quota->histogram[score]; | |
1163 | if (cumulated_sz >= quota->esz || !score) | |
1164 | break; | |
1165 | } | |
1166 | quota->min_score = score; | |
1167 | } | |
38683e00 | 1168 | |
898810e5 SP |
1169 | static void kdamond_apply_schemes(struct damon_ctx *c) |
1170 | { | |
1171 | struct damon_target *t; | |
1172 | struct damon_region *r, *next_r; | |
1173 | struct damos *s; | |
42f994b7 SP |
1174 | unsigned long sample_interval = c->attrs.sample_interval ? |
1175 | c->attrs.sample_interval : 1; | |
1176 | bool has_schemes_to_apply = false; | |
38683e00 | 1177 | |
898810e5 | 1178 | damon_for_each_scheme(s, c) { |
42f994b7 SP |
1179 | if (c->passed_sample_intervals != s->next_apply_sis) |
1180 | continue; | |
1181 | ||
898810e5 SP |
1182 | if (!s->wmarks.activated) |
1183 | continue; | |
1184 | ||
42f994b7 SP |
1185 | has_schemes_to_apply = true; |
1186 | ||
898810e5 | 1187 | damos_adjust_quota(c, s); |
2b8a248d | 1188 | } |
1f366e42 | 1189 | |
42f994b7 SP |
1190 | if (!has_schemes_to_apply) |
1191 | return; | |
1192 | ||
1f366e42 | 1193 | damon_for_each_target(t, c) { |
2b8a248d | 1194 | damon_for_each_region_safe(r, next_r, t) |
1f366e42 SP |
1195 | damon_do_apply_schemes(c, t, r); |
1196 | } | |
e9e3db69 SP |
1197 | |
1198 | damon_for_each_scheme(s, c) { | |
1199 | if (c->passed_sample_intervals != s->next_apply_sis) | |
1200 | continue; | |
1201 | s->next_apply_sis += | |
1202 | (s->apply_interval_us ? s->apply_interval_us : | |
1203 | c->attrs.aggr_interval) / sample_interval; | |
1204 | } | |
1f366e42 SP |
1205 | } |
1206 | ||
b9a6ac4e SP |
1207 | /* |
1208 | * Merge two adjacent regions into one region | |
1209 | */ | |
1210 | static void damon_merge_two_regions(struct damon_target *t, | |
1211 | struct damon_region *l, struct damon_region *r) | |
1212 | { | |
652e0446 | 1213 | unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r); |
b9a6ac4e SP |
1214 | |
1215 | l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / | |
1216 | (sz_l + sz_r); | |
80333828 | 1217 | l->nr_accesses_bp = l->nr_accesses * 10000; |
fda504fa | 1218 | l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); |
b9a6ac4e SP |
1219 | l->ar.end = r->ar.end; |
1220 | damon_destroy_region(r, t); | |
1221 | } | |
1222 | ||
b9a6ac4e SP |
1223 | /* |
1224 | * Merge adjacent regions having similar access frequencies | |
1225 | * | |
1226 | * t target affected by this merge operation | |
1227 | * thres '->nr_accesses' diff threshold for the merge | |
1228 | * sz_limit size upper limit of each region | |
1229 | */ | |
1230 | static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, | |
1231 | unsigned long sz_limit) | |
1232 | { | |
1233 | struct damon_region *r, *prev = NULL, *next; | |
1234 | ||
1235 | damon_for_each_region_safe(r, next, t) { | |
d720bbbd | 1236 | if (abs(r->nr_accesses - r->last_nr_accesses) > thres) |
fda504fa SP |
1237 | r->age = 0; |
1238 | else | |
1239 | r->age++; | |
1240 | ||
b9a6ac4e | 1241 | if (prev && prev->ar.end == r->ar.start && |
d720bbbd | 1242 | abs(prev->nr_accesses - r->nr_accesses) <= thres && |
652e0446 | 1243 | damon_sz_region(prev) + damon_sz_region(r) <= sz_limit) |
b9a6ac4e SP |
1244 | damon_merge_two_regions(t, prev, r); |
1245 | else | |
1246 | prev = r; | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | /* | |
1251 | * Merge adjacent regions having similar access frequencies | |
1252 | * | |
1253 | * threshold '->nr_accesses' diff threshold for the merge | |
1254 | * sz_limit size upper limit of each region | |
1255 | * | |
1256 | * This function merges monitoring target regions which are adjacent and their | |
1257 | * access frequencies are similar. This is for minimizing the monitoring | |
1258 | * overhead under the dynamically changeable access pattern. If a merge was | |
1259 | * unnecessarily made, later 'kdamond_split_regions()' will revert it. | |
1260 | */ | |
1261 | static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, | |
1262 | unsigned long sz_limit) | |
1263 | { | |
1264 | struct damon_target *t; | |
1265 | ||
1266 | damon_for_each_target(t, c) | |
1267 | damon_merge_regions_of(t, threshold, sz_limit); | |
1268 | } | |
1269 | ||
1270 | /* | |
1271 | * Split a region in two | |
1272 | * | |
1273 | * r the region to be split | |
1274 | * sz_r size of the first sub-region that will be made | |
1275 | */ | |
4ed98243 KX |
1276 | static void damon_split_region_at(struct damon_target *t, |
1277 | struct damon_region *r, unsigned long sz_r) | |
b9a6ac4e SP |
1278 | { |
1279 | struct damon_region *new; | |
1280 | ||
1281 | new = damon_new_region(r->ar.start + sz_r, r->ar.end); | |
1282 | if (!new) | |
1283 | return; | |
1284 | ||
1285 | r->ar.end = new->ar.start; | |
1286 | ||
fda504fa SP |
1287 | new->age = r->age; |
1288 | new->last_nr_accesses = r->last_nr_accesses; | |
80333828 | 1289 | new->nr_accesses_bp = r->nr_accesses_bp; |
1f3730fd | 1290 | new->nr_accesses = r->nr_accesses; |
fda504fa | 1291 | |
b9a6ac4e SP |
1292 | damon_insert_region(new, r, damon_next_region(r), t); |
1293 | } | |
1294 | ||
1295 | /* Split every region in the given target into 'nr_subs' regions */ | |
4ed98243 | 1296 | static void damon_split_regions_of(struct damon_target *t, int nr_subs) |
b9a6ac4e SP |
1297 | { |
1298 | struct damon_region *r, *next; | |
1299 | unsigned long sz_region, sz_sub = 0; | |
1300 | int i; | |
1301 | ||
1302 | damon_for_each_region_safe(r, next, t) { | |
ab63f63f | 1303 | sz_region = damon_sz_region(r); |
b9a6ac4e SP |
1304 | |
1305 | for (i = 0; i < nr_subs - 1 && | |
1306 | sz_region > 2 * DAMON_MIN_REGION; i++) { | |
1307 | /* | |
1308 | * Randomly select size of left sub-region to be at | |
1309 | * least 10 percent and at most 90% of original region | |
1310 | */ | |
1311 | sz_sub = ALIGN_DOWN(damon_rand(1, 10) * | |
1312 | sz_region / 10, DAMON_MIN_REGION); | |
1313 | /* Do not allow blank region */ | |
1314 | if (sz_sub == 0 || sz_sub >= sz_region) | |
1315 | continue; | |
1316 | ||
4ed98243 | 1317 | damon_split_region_at(t, r, sz_sub); |
b9a6ac4e SP |
1318 | sz_region = sz_sub; |
1319 | } | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | /* | |
1324 | * Split every target region into randomly-sized small regions | |
1325 | * | |
1326 | * This function splits every target region into random-sized small regions if | |
1327 | * current total number of the regions is equal or smaller than half of the | |
1328 | * user-specified maximum number of regions. This is for maximizing the | |
1329 | * monitoring accuracy under the dynamically changeable access patterns. If a | |
1330 | * split was unnecessarily made, later 'kdamond_merge_regions()' will revert | |
1331 | * it. | |
1332 | */ | |
1333 | static void kdamond_split_regions(struct damon_ctx *ctx) | |
1334 | { | |
1335 | struct damon_target *t; | |
1336 | unsigned int nr_regions = 0; | |
1337 | static unsigned int last_nr_regions; | |
1338 | int nr_subregions = 2; | |
1339 | ||
1340 | damon_for_each_target(t, ctx) | |
1341 | nr_regions += damon_nr_regions(t); | |
1342 | ||
cbeaa77b | 1343 | if (nr_regions > ctx->attrs.max_nr_regions / 2) |
b9a6ac4e SP |
1344 | return; |
1345 | ||
1346 | /* Maybe the middle of the region has different access frequency */ | |
1347 | if (last_nr_regions == nr_regions && | |
cbeaa77b | 1348 | nr_regions < ctx->attrs.max_nr_regions / 3) |
b9a6ac4e SP |
1349 | nr_subregions = 3; |
1350 | ||
1351 | damon_for_each_target(t, ctx) | |
4ed98243 | 1352 | damon_split_regions_of(t, nr_subregions); |
b9a6ac4e SP |
1353 | |
1354 | last_nr_regions = nr_regions; | |
1355 | } | |
1356 | ||
2224d848 SP |
1357 | /* |
1358 | * Check whether current monitoring should be stopped | |
1359 | * | |
1360 | * The monitoring is stopped when either the user requested to stop, or all | |
1361 | * monitoring targets are invalid. | |
1362 | * | |
1363 | * Returns true if need to stop current monitoring. | |
1364 | */ | |
1365 | static bool kdamond_need_stop(struct damon_ctx *ctx) | |
1366 | { | |
f23b8eee | 1367 | struct damon_target *t; |
2224d848 | 1368 | |
0f91d133 | 1369 | if (kthread_should_stop()) |
2224d848 SP |
1370 | return true; |
1371 | ||
f7d911c3 | 1372 | if (!ctx->ops.target_valid) |
2224d848 SP |
1373 | return false; |
1374 | ||
f23b8eee | 1375 | damon_for_each_target(t, ctx) { |
f7d911c3 | 1376 | if (ctx->ops.target_valid(t)) |
f23b8eee SP |
1377 | return false; |
1378 | } | |
1379 | ||
1380 | return true; | |
2224d848 SP |
1381 | } |
1382 | ||
ee801b7d SP |
1383 | static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) |
1384 | { | |
ee801b7d SP |
1385 | switch (metric) { |
1386 | case DAMOS_WMARK_FREE_MEM_RATE: | |
987ffa5a HY |
1387 | return global_zone_page_state(NR_FREE_PAGES) * 1000 / |
1388 | totalram_pages(); | |
ee801b7d SP |
1389 | default: |
1390 | break; | |
1391 | } | |
1392 | return -EINVAL; | |
1393 | } | |
1394 | ||
1395 | /* | |
1396 | * Returns zero if the scheme is active. Else, returns time to wait for next | |
1397 | * watermark check in micro-seconds. | |
1398 | */ | |
1399 | static unsigned long damos_wmark_wait_us(struct damos *scheme) | |
1400 | { | |
1401 | unsigned long metric; | |
1402 | ||
1403 | if (scheme->wmarks.metric == DAMOS_WMARK_NONE) | |
1404 | return 0; | |
1405 | ||
1406 | metric = damos_wmark_metric_value(scheme->wmarks.metric); | |
1407 | /* higher than high watermark or lower than low watermark */ | |
1408 | if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { | |
1409 | if (scheme->wmarks.activated) | |
01078655 | 1410 | pr_debug("deactivate a scheme (%d) for %s wmark\n", |
ee801b7d SP |
1411 | scheme->action, |
1412 | metric > scheme->wmarks.high ? | |
1413 | "high" : "low"); | |
1414 | scheme->wmarks.activated = false; | |
1415 | return scheme->wmarks.interval; | |
1416 | } | |
1417 | ||
1418 | /* inactive and higher than middle watermark */ | |
1419 | if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && | |
1420 | !scheme->wmarks.activated) | |
1421 | return scheme->wmarks.interval; | |
1422 | ||
1423 | if (!scheme->wmarks.activated) | |
1424 | pr_debug("activate a scheme (%d)\n", scheme->action); | |
1425 | scheme->wmarks.activated = true; | |
1426 | return 0; | |
1427 | } | |
1428 | ||
1429 | static void kdamond_usleep(unsigned long usecs) | |
1430 | { | |
4de46a30 SP |
1431 | /* See Documentation/timers/timers-howto.rst for the thresholds */ |
1432 | if (usecs > 20 * USEC_PER_MSEC) | |
70e92748 | 1433 | schedule_timeout_idle(usecs_to_jiffies(usecs)); |
ee801b7d | 1434 | else |
70e92748 | 1435 | usleep_idle_range(usecs, usecs + 1); |
ee801b7d SP |
1436 | } |
1437 | ||
1438 | /* Returns negative error code if it's not activated but should return */ | |
1439 | static int kdamond_wait_activation(struct damon_ctx *ctx) | |
1440 | { | |
1441 | struct damos *s; | |
1442 | unsigned long wait_time; | |
1443 | unsigned long min_wait_time = 0; | |
78049e94 | 1444 | bool init_wait_time = false; |
ee801b7d SP |
1445 | |
1446 | while (!kdamond_need_stop(ctx)) { | |
1447 | damon_for_each_scheme(s, ctx) { | |
1448 | wait_time = damos_wmark_wait_us(s); | |
78049e94 JK |
1449 | if (!init_wait_time || wait_time < min_wait_time) { |
1450 | init_wait_time = true; | |
ee801b7d | 1451 | min_wait_time = wait_time; |
78049e94 | 1452 | } |
ee801b7d SP |
1453 | } |
1454 | if (!min_wait_time) | |
1455 | return 0; | |
1456 | ||
1457 | kdamond_usleep(min_wait_time); | |
6e74d2bf SP |
1458 | |
1459 | if (ctx->callback.after_wmarks_check && | |
1460 | ctx->callback.after_wmarks_check(ctx)) | |
1461 | break; | |
ee801b7d SP |
1462 | } |
1463 | return -EBUSY; | |
1464 | } | |
1465 | ||
4472edf6 SP |
1466 | static void kdamond_init_intervals_sis(struct damon_ctx *ctx) |
1467 | { | |
1468 | unsigned long sample_interval = ctx->attrs.sample_interval ? | |
1469 | ctx->attrs.sample_interval : 1; | |
42f994b7 SP |
1470 | unsigned long apply_interval; |
1471 | struct damos *scheme; | |
4472edf6 SP |
1472 | |
1473 | ctx->passed_sample_intervals = 0; | |
1474 | ctx->next_aggregation_sis = ctx->attrs.aggr_interval / sample_interval; | |
1475 | ctx->next_ops_update_sis = ctx->attrs.ops_update_interval / | |
1476 | sample_interval; | |
42f994b7 SP |
1477 | |
1478 | damon_for_each_scheme(scheme, ctx) { | |
1479 | apply_interval = scheme->apply_interval_us ? | |
1480 | scheme->apply_interval_us : ctx->attrs.aggr_interval; | |
1481 | scheme->next_apply_sis = apply_interval / sample_interval; | |
1482 | } | |
4472edf6 SP |
1483 | } |
1484 | ||
2224d848 SP |
1485 | /* |
1486 | * The monitoring daemon that runs as a kernel thread | |
1487 | */ | |
1488 | static int kdamond_fn(void *data) | |
1489 | { | |
cef4493f | 1490 | struct damon_ctx *ctx = data; |
f23b8eee SP |
1491 | struct damon_target *t; |
1492 | struct damon_region *r, *next; | |
b9a6ac4e SP |
1493 | unsigned int max_nr_accesses = 0; |
1494 | unsigned long sz_limit = 0; | |
2224d848 | 1495 | |
42e4cef5 | 1496 | pr_debug("kdamond (%d) starts\n", current->pid); |
2224d848 | 1497 | |
6376a824 | 1498 | complete(&ctx->kdamond_started); |
4472edf6 SP |
1499 | kdamond_init_intervals_sis(ctx); |
1500 | ||
f7d911c3 SP |
1501 | if (ctx->ops.init) |
1502 | ctx->ops.init(ctx); | |
2224d848 | 1503 | if (ctx->callback.before_start && ctx->callback.before_start(ctx)) |
29454cf6 | 1504 | goto done; |
2224d848 | 1505 | |
b9a6ac4e SP |
1506 | sz_limit = damon_region_sz_limit(ctx); |
1507 | ||
29454cf6 | 1508 | while (!kdamond_need_stop(ctx)) { |
4472edf6 SP |
1509 | /* |
1510 | * ctx->attrs and ctx->next_{aggregation,ops_update}_sis could | |
1511 | * be changed from after_wmarks_check() or after_aggregation() | |
1512 | * callbacks. Read the values here, and use those for this | |
1513 | * iteration. That is, damon_set_attrs() updated new values | |
1514 | * are respected from next iteration. | |
1515 | */ | |
1516 | unsigned long next_aggregation_sis = ctx->next_aggregation_sis; | |
1517 | unsigned long next_ops_update_sis = ctx->next_ops_update_sis; | |
1518 | unsigned long sample_interval = ctx->attrs.sample_interval; | |
1519 | ||
29454cf6 KX |
1520 | if (kdamond_wait_activation(ctx)) |
1521 | break; | |
ee801b7d | 1522 | |
f7d911c3 SP |
1523 | if (ctx->ops.prepare_access_checks) |
1524 | ctx->ops.prepare_access_checks(ctx); | |
2224d848 | 1525 | if (ctx->callback.after_sampling && |
29454cf6 KX |
1526 | ctx->callback.after_sampling(ctx)) |
1527 | break; | |
2224d848 | 1528 | |
4472edf6 SP |
1529 | kdamond_usleep(sample_interval); |
1530 | ctx->passed_sample_intervals++; | |
2224d848 | 1531 | |
f7d911c3 SP |
1532 | if (ctx->ops.check_accesses) |
1533 | max_nr_accesses = ctx->ops.check_accesses(ctx); | |
2224d848 | 1534 | |
4472edf6 | 1535 | if (ctx->passed_sample_intervals == next_aggregation_sis) { |
b9a6ac4e SP |
1536 | kdamond_merge_regions(ctx, |
1537 | max_nr_accesses / 10, | |
1538 | sz_limit); | |
2224d848 | 1539 | if (ctx->callback.after_aggregation && |
29454cf6 KX |
1540 | ctx->callback.after_aggregation(ctx)) |
1541 | break; | |
42f994b7 SP |
1542 | } |
1543 | ||
1544 | /* | |
1545 | * do kdamond_apply_schemes() after kdamond_merge_regions() if | |
1546 | * possible, to reduce overhead | |
1547 | */ | |
1548 | if (!list_empty(&ctx->schemes)) | |
1549 | kdamond_apply_schemes(ctx); | |
1550 | ||
1551 | sample_interval = ctx->attrs.sample_interval ? | |
1552 | ctx->attrs.sample_interval : 1; | |
1553 | if (ctx->passed_sample_intervals == next_aggregation_sis) { | |
1554 | ctx->next_aggregation_sis = next_aggregation_sis + | |
1555 | ctx->attrs.aggr_interval / sample_interval; | |
1556 | ||
f23b8eee | 1557 | kdamond_reset_aggregated(ctx); |
b9a6ac4e | 1558 | kdamond_split_regions(ctx); |
f7d911c3 SP |
1559 | if (ctx->ops.reset_aggregated) |
1560 | ctx->ops.reset_aggregated(ctx); | |
2224d848 SP |
1561 | } |
1562 | ||
4472edf6 SP |
1563 | if (ctx->passed_sample_intervals == next_ops_update_sis) { |
1564 | ctx->next_ops_update_sis = next_ops_update_sis + | |
1565 | ctx->attrs.ops_update_interval / | |
1566 | sample_interval; | |
f7d911c3 SP |
1567 | if (ctx->ops.update) |
1568 | ctx->ops.update(ctx); | |
b9a6ac4e | 1569 | sz_limit = damon_region_sz_limit(ctx); |
2224d848 SP |
1570 | } |
1571 | } | |
29454cf6 | 1572 | done: |
f23b8eee SP |
1573 | damon_for_each_target(t, ctx) { |
1574 | damon_for_each_region_safe(r, next, t) | |
b9a6ac4e | 1575 | damon_destroy_region(r, t); |
f23b8eee | 1576 | } |
2224d848 | 1577 | |
0f91d133 CD |
1578 | if (ctx->callback.before_terminate) |
1579 | ctx->callback.before_terminate(ctx); | |
f7d911c3 SP |
1580 | if (ctx->ops.cleanup) |
1581 | ctx->ops.cleanup(ctx); | |
2224d848 | 1582 | |
42e4cef5 | 1583 | pr_debug("kdamond (%d) finishes\n", current->pid); |
2224d848 SP |
1584 | mutex_lock(&ctx->kdamond_lock); |
1585 | ctx->kdamond = NULL; | |
1586 | mutex_unlock(&ctx->kdamond_lock); | |
1587 | ||
1588 | mutex_lock(&damon_lock); | |
1589 | nr_running_ctxs--; | |
8b9b0d33 SP |
1590 | if (!nr_running_ctxs && running_exclusive_ctxs) |
1591 | running_exclusive_ctxs = false; | |
2224d848 SP |
1592 | mutex_unlock(&damon_lock); |
1593 | ||
5f7fe2b9 | 1594 | return 0; |
2224d848 | 1595 | } |
17ccae8b | 1596 | |
0d83b2d8 XH |
1597 | /* |
1598 | * struct damon_system_ram_region - System RAM resource address region of | |
1599 | * [@start, @end). | |
1600 | * @start: Start address of the region (inclusive). | |
1601 | * @end: End address of the region (exclusive). | |
1602 | */ | |
1603 | struct damon_system_ram_region { | |
1604 | unsigned long start; | |
1605 | unsigned long end; | |
1606 | }; | |
1607 | ||
1608 | static int walk_system_ram(struct resource *res, void *arg) | |
1609 | { | |
1610 | struct damon_system_ram_region *a = arg; | |
1611 | ||
1612 | if (a->end - a->start < resource_size(res)) { | |
1613 | a->start = res->start; | |
1614 | a->end = res->end; | |
1615 | } | |
1616 | return 0; | |
1617 | } | |
1618 | ||
1619 | /* | |
1620 | * Find biggest 'System RAM' resource and store its start and end address in | |
1621 | * @start and @end, respectively. If no System RAM is found, returns false. | |
1622 | */ | |
233f0b31 KX |
1623 | static bool damon_find_biggest_system_ram(unsigned long *start, |
1624 | unsigned long *end) | |
0d83b2d8 XH |
1625 | |
1626 | { | |
1627 | struct damon_system_ram_region arg = {}; | |
1628 | ||
1629 | walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram); | |
1630 | if (arg.end <= arg.start) | |
1631 | return false; | |
1632 | ||
1633 | *start = arg.start; | |
1634 | *end = arg.end; | |
1635 | return true; | |
1636 | } | |
1637 | ||
233f0b31 KX |
1638 | /** |
1639 | * damon_set_region_biggest_system_ram_default() - Set the region of the given | |
1640 | * monitoring target as requested, or biggest 'System RAM'. | |
1641 | * @t: The monitoring target to set the region. | |
1642 | * @start: The pointer to the start address of the region. | |
1643 | * @end: The pointer to the end address of the region. | |
1644 | * | |
1645 | * This function sets the region of @t as requested by @start and @end. If the | |
1646 | * values of @start and @end are zero, however, this function finds the biggest | |
1647 | * 'System RAM' resource and sets the region to cover the resource. In the | |
1648 | * latter case, this function saves the start and end addresses of the resource | |
1649 | * in @start and @end, respectively. | |
1650 | * | |
1651 | * Return: 0 on success, negative error code otherwise. | |
1652 | */ | |
1653 | int damon_set_region_biggest_system_ram_default(struct damon_target *t, | |
1654 | unsigned long *start, unsigned long *end) | |
1655 | { | |
1656 | struct damon_addr_range addr_range; | |
1657 | ||
1658 | if (*start > *end) | |
1659 | return -EINVAL; | |
1660 | ||
1661 | if (!*start && !*end && | |
1662 | !damon_find_biggest_system_ram(start, end)) | |
1663 | return -EINVAL; | |
1664 | ||
1665 | addr_range.start = *start; | |
1666 | addr_range.end = *end; | |
1667 | return damon_set_regions(t, &addr_range, 1); | |
1668 | } | |
1669 | ||
d2c062ad SP |
1670 | /* |
1671 | * damon_moving_sum() - Calculate an inferred moving sum value. | |
1672 | * @mvsum: Inferred sum of the last @len_window values. | |
1673 | * @nomvsum: Non-moving sum of the last discrete @len_window window values. | |
1674 | * @len_window: The number of last values to take care of. | |
1675 | * @new_value: New value that will be added to the pseudo moving sum. | |
1676 | * | |
1677 | * Moving sum (moving average * window size) is good for handling noise, but | |
1678 | * the cost of keeping past values can be high for arbitrary window size. This | |
1679 | * function implements a lightweight pseudo moving sum function that doesn't | |
1680 | * keep the past window values. | |
1681 | * | |
1682 | * It simply assumes there was no noise in the past, and get the no-noise | |
1683 | * assumed past value to drop from @nomvsum and @len_window. @nomvsum is a | |
1684 | * non-moving sum of the last window. For example, if @len_window is 10 and we | |
1685 | * have 25 values, @nomvsum is the sum of the 11th to 20th values of the 25 | |
1686 | * values. Hence, this function simply drops @nomvsum / @len_window from | |
1687 | * given @mvsum and add @new_value. | |
1688 | * | |
1689 | * For example, if @len_window is 10 and @nomvsum is 50, the last 10 values for | |
1690 | * the last window could be vary, e.g., 0, 10, 0, 10, 0, 10, 0, 0, 0, 20. For | |
1691 | * calculating next moving sum with a new value, we should drop 0 from 50 and | |
1692 | * add the new value. However, this function assumes it got value 5 for each | |
1693 | * of the last ten times. Based on the assumption, when the next value is | |
1694 | * measured, it drops the assumed past value, 5 from the current sum, and add | |
1695 | * the new value to get the updated pseduo-moving average. | |
1696 | * | |
1697 | * This means the value could have errors, but the errors will be disappeared | |
1698 | * for every @len_window aligned calls. For example, if @len_window is 10, the | |
1699 | * pseudo moving sum with 11th value to 19th value would have an error. But | |
1700 | * the sum with 20th value will not have the error. | |
1701 | * | |
1702 | * Return: Pseudo-moving average after getting the @new_value. | |
1703 | */ | |
863803a7 | 1704 | static unsigned int damon_moving_sum(unsigned int mvsum, unsigned int nomvsum, |
d2c062ad SP |
1705 | unsigned int len_window, unsigned int new_value) |
1706 | { | |
1707 | return mvsum - nomvsum / len_window + new_value; | |
1708 | } | |
1709 | ||
78fbfb15 SP |
1710 | /** |
1711 | * damon_update_region_access_rate() - Update the access rate of a region. | |
1712 | * @r: The DAMON region to update for its access check result. | |
1713 | * @accessed: Whether the region has accessed during last sampling interval. | |
ace30fb2 | 1714 | * @attrs: The damon_attrs of the DAMON context. |
78fbfb15 SP |
1715 | * |
1716 | * Update the access rate of a region with the region's last sampling interval | |
1717 | * access check result. | |
1718 | * | |
1719 | * Usually this will be called by &damon_operations->check_accesses callback. | |
1720 | */ | |
ace30fb2 SP |
1721 | void damon_update_region_access_rate(struct damon_region *r, bool accessed, |
1722 | struct damon_attrs *attrs) | |
78fbfb15 | 1723 | { |
ace30fb2 SP |
1724 | unsigned int len_window = 1; |
1725 | ||
1726 | /* | |
1727 | * sample_interval can be zero, but cannot be larger than | |
1728 | * aggr_interval, owing to validation of damon_set_attrs(). | |
1729 | */ | |
1730 | if (attrs->sample_interval) | |
62f76a7b | 1731 | len_window = damon_max_nr_accesses(attrs); |
ace30fb2 SP |
1732 | r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp, |
1733 | r->last_nr_accesses * 10000, len_window, | |
1734 | accessed ? 10000 : 0); | |
1735 | ||
78fbfb15 SP |
1736 | if (accessed) |
1737 | r->nr_accesses++; | |
1738 | } | |
1739 | ||
a1870944 DL |
1740 | static int __init damon_init(void) |
1741 | { | |
1742 | damon_region_cache = KMEM_CACHE(damon_region, 0); | |
1743 | if (unlikely(!damon_region_cache)) { | |
1744 | pr_err("creating damon_region_cache fails\n"); | |
1745 | return -ENOMEM; | |
1746 | } | |
1747 | ||
1748 | return 0; | |
1749 | } | |
1750 | ||
1751 | subsys_initcall(damon_init); | |
1752 | ||
17ccae8b | 1753 | #include "core-test.h" |