12224d848SSeongJae Park // SPDX-License-Identifier: GPL-2.0 22224d848SSeongJae Park /* 32224d848SSeongJae Park * Data Access Monitor 42224d848SSeongJae Park * 52224d848SSeongJae Park * Author: SeongJae Park <sjpark@amazon.de> 62224d848SSeongJae Park */ 72224d848SSeongJae Park 82224d848SSeongJae Park #define pr_fmt(fmt) "damon: " fmt 92224d848SSeongJae Park 102224d848SSeongJae Park #include <linux/damon.h> 112224d848SSeongJae Park #include <linux/delay.h> 122224d848SSeongJae Park #include <linux/kthread.h> 13ee801b7dSSeongJae Park #include <linux/mm.h> 142224d848SSeongJae Park #include <linux/slab.h> 1538683e00SSeongJae Park #include <linux/string.h> 162224d848SSeongJae Park 172fcb9362SSeongJae Park #define CREATE_TRACE_POINTS 182fcb9362SSeongJae Park #include <trace/events/damon.h> 192fcb9362SSeongJae Park 2017ccae8bSSeongJae Park #ifdef CONFIG_DAMON_KUNIT_TEST 2117ccae8bSSeongJae Park #undef DAMON_MIN_REGION 2217ccae8bSSeongJae Park #define DAMON_MIN_REGION 1 2317ccae8bSSeongJae Park #endif 2417ccae8bSSeongJae Park 252224d848SSeongJae Park static DEFINE_MUTEX(damon_lock); 262224d848SSeongJae Park static int nr_running_ctxs; 278b9b0d33SSeongJae Park static bool running_exclusive_ctxs; 282224d848SSeongJae Park 299f7b053aSSeongJae Park static DEFINE_MUTEX(damon_ops_lock); 309f7b053aSSeongJae Park static struct damon_operations damon_registered_ops[NR_DAMON_OPS]; 319f7b053aSSeongJae Park 32a1870944SDawei Li static struct kmem_cache *damon_region_cache __ro_after_init; 33a1870944SDawei Li 349f7b053aSSeongJae Park /* Should be called under damon_ops_lock with id smaller than NR_DAMON_OPS */ 35152e5617SSeongJae Park static bool __damon_is_registered_ops(enum damon_ops_id id) 369f7b053aSSeongJae Park { 379f7b053aSSeongJae Park struct damon_operations empty_ops = {}; 389f7b053aSSeongJae Park 399f7b053aSSeongJae Park if (!memcmp(&empty_ops, &damon_registered_ops[id], sizeof(empty_ops))) 409f7b053aSSeongJae Park return false; 419f7b053aSSeongJae Park return true; 429f7b053aSSeongJae Park } 439f7b053aSSeongJae Park 449f7b053aSSeongJae Park /** 45152e5617SSeongJae Park * damon_is_registered_ops() - Check if a given damon_operations is registered. 46152e5617SSeongJae Park * @id: Id of the damon_operations to check if registered. 47152e5617SSeongJae Park * 48152e5617SSeongJae Park * Return: true if the ops is set, false otherwise. 49152e5617SSeongJae Park */ 50152e5617SSeongJae Park bool damon_is_registered_ops(enum damon_ops_id id) 51152e5617SSeongJae Park { 52152e5617SSeongJae Park bool registered; 53152e5617SSeongJae Park 54152e5617SSeongJae Park if (id >= NR_DAMON_OPS) 55152e5617SSeongJae Park return false; 56152e5617SSeongJae Park mutex_lock(&damon_ops_lock); 57152e5617SSeongJae Park registered = __damon_is_registered_ops(id); 58152e5617SSeongJae Park mutex_unlock(&damon_ops_lock); 59152e5617SSeongJae Park return registered; 60152e5617SSeongJae Park } 61152e5617SSeongJae Park 62152e5617SSeongJae Park /** 639f7b053aSSeongJae Park * damon_register_ops() - Register a monitoring operations set to DAMON. 649f7b053aSSeongJae Park * @ops: monitoring operations set to register. 659f7b053aSSeongJae Park * 669f7b053aSSeongJae Park * This function registers a monitoring operations set of valid &struct 679f7b053aSSeongJae Park * damon_operations->id so that others can find and use them later. 689f7b053aSSeongJae Park * 699f7b053aSSeongJae Park * Return: 0 on success, negative error code otherwise. 709f7b053aSSeongJae Park */ 719f7b053aSSeongJae Park int damon_register_ops(struct damon_operations *ops) 729f7b053aSSeongJae Park { 739f7b053aSSeongJae Park int err = 0; 749f7b053aSSeongJae Park 759f7b053aSSeongJae Park if (ops->id >= NR_DAMON_OPS) 769f7b053aSSeongJae Park return -EINVAL; 779f7b053aSSeongJae Park mutex_lock(&damon_ops_lock); 789f7b053aSSeongJae Park /* Fail for already registered ops */ 79152e5617SSeongJae Park if (__damon_is_registered_ops(ops->id)) { 809f7b053aSSeongJae Park err = -EINVAL; 819f7b053aSSeongJae Park goto out; 829f7b053aSSeongJae Park } 839f7b053aSSeongJae Park damon_registered_ops[ops->id] = *ops; 849f7b053aSSeongJae Park out: 859f7b053aSSeongJae Park mutex_unlock(&damon_ops_lock); 869f7b053aSSeongJae Park return err; 879f7b053aSSeongJae Park } 889f7b053aSSeongJae Park 899f7b053aSSeongJae Park /** 909f7b053aSSeongJae Park * damon_select_ops() - Select a monitoring operations to use with the context. 919f7b053aSSeongJae Park * @ctx: monitoring context to use the operations. 929f7b053aSSeongJae Park * @id: id of the registered monitoring operations to select. 939f7b053aSSeongJae Park * 949f7b053aSSeongJae Park * This function finds registered monitoring operations set of @id and make 959f7b053aSSeongJae Park * @ctx to use it. 969f7b053aSSeongJae Park * 979f7b053aSSeongJae Park * Return: 0 on success, negative error code otherwise. 989f7b053aSSeongJae Park */ 999f7b053aSSeongJae Park int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id) 1009f7b053aSSeongJae Park { 1019f7b053aSSeongJae Park int err = 0; 1029f7b053aSSeongJae Park 1039f7b053aSSeongJae Park if (id >= NR_DAMON_OPS) 1049f7b053aSSeongJae Park return -EINVAL; 1059f7b053aSSeongJae Park 1069f7b053aSSeongJae Park mutex_lock(&damon_ops_lock); 107152e5617SSeongJae Park if (!__damon_is_registered_ops(id)) 1089f7b053aSSeongJae Park err = -EINVAL; 1099f7b053aSSeongJae Park else 1109f7b053aSSeongJae Park ctx->ops = damon_registered_ops[id]; 1119f7b053aSSeongJae Park mutex_unlock(&damon_ops_lock); 1129f7b053aSSeongJae Park return err; 1139f7b053aSSeongJae Park } 1149f7b053aSSeongJae Park 115f23b8eeeSSeongJae Park /* 116f23b8eeeSSeongJae Park * Construct a damon_region struct 117f23b8eeeSSeongJae Park * 118f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 119f23b8eeeSSeongJae Park */ 120f23b8eeeSSeongJae Park struct damon_region *damon_new_region(unsigned long start, unsigned long end) 121f23b8eeeSSeongJae Park { 122f23b8eeeSSeongJae Park struct damon_region *region; 123f23b8eeeSSeongJae Park 124a1870944SDawei Li region = kmem_cache_alloc(damon_region_cache, GFP_KERNEL); 125f23b8eeeSSeongJae Park if (!region) 126f23b8eeeSSeongJae Park return NULL; 127f23b8eeeSSeongJae Park 128f23b8eeeSSeongJae Park region->ar.start = start; 129f23b8eeeSSeongJae Park region->ar.end = end; 130f23b8eeeSSeongJae Park region->nr_accesses = 0; 131f23b8eeeSSeongJae Park INIT_LIST_HEAD(®ion->list); 132f23b8eeeSSeongJae Park 133fda504faSSeongJae Park region->age = 0; 134fda504faSSeongJae Park region->last_nr_accesses = 0; 135fda504faSSeongJae Park 136f23b8eeeSSeongJae Park return region; 137f23b8eeeSSeongJae Park } 138f23b8eeeSSeongJae Park 139f23b8eeeSSeongJae Park void damon_add_region(struct damon_region *r, struct damon_target *t) 140f23b8eeeSSeongJae Park { 141f23b8eeeSSeongJae Park list_add_tail(&r->list, &t->regions_list); 142b9a6ac4eSSeongJae Park t->nr_regions++; 143f23b8eeeSSeongJae Park } 144f23b8eeeSSeongJae Park 145b9a6ac4eSSeongJae Park static void damon_del_region(struct damon_region *r, struct damon_target *t) 146f23b8eeeSSeongJae Park { 147f23b8eeeSSeongJae Park list_del(&r->list); 148b9a6ac4eSSeongJae Park t->nr_regions--; 149f23b8eeeSSeongJae Park } 150f23b8eeeSSeongJae Park 151f23b8eeeSSeongJae Park static void damon_free_region(struct damon_region *r) 152f23b8eeeSSeongJae Park { 153a1870944SDawei Li kmem_cache_free(damon_region_cache, r); 154f23b8eeeSSeongJae Park } 155f23b8eeeSSeongJae Park 156b9a6ac4eSSeongJae Park void damon_destroy_region(struct damon_region *r, struct damon_target *t) 157f23b8eeeSSeongJae Park { 158b9a6ac4eSSeongJae Park damon_del_region(r, t); 159f23b8eeeSSeongJae Park damon_free_region(r); 160f23b8eeeSSeongJae Park } 161f23b8eeeSSeongJae Park 162d0723bc0SSeongJae Park /* 163d0723bc0SSeongJae Park * Check whether a region is intersecting an address range 164d0723bc0SSeongJae Park * 165d0723bc0SSeongJae Park * Returns true if it is. 166d0723bc0SSeongJae Park */ 167d0723bc0SSeongJae Park static bool damon_intersect(struct damon_region *r, 168d0723bc0SSeongJae Park struct damon_addr_range *re) 169d0723bc0SSeongJae Park { 170d0723bc0SSeongJae Park return !(r->ar.end <= re->start || re->end <= r->ar.start); 171d0723bc0SSeongJae Park } 172d0723bc0SSeongJae Park 173d0723bc0SSeongJae Park /* 1749c950c22SSeongJae Park * Fill holes in regions with new regions. 1759c950c22SSeongJae Park */ 1769c950c22SSeongJae Park static int damon_fill_regions_holes(struct damon_region *first, 1779c950c22SSeongJae Park struct damon_region *last, struct damon_target *t) 1789c950c22SSeongJae Park { 1799c950c22SSeongJae Park struct damon_region *r = first; 1809c950c22SSeongJae Park 1819c950c22SSeongJae Park damon_for_each_region_from(r, t) { 1829c950c22SSeongJae Park struct damon_region *next, *newr; 1839c950c22SSeongJae Park 1849c950c22SSeongJae Park if (r == last) 1859c950c22SSeongJae Park break; 1869c950c22SSeongJae Park next = damon_next_region(r); 1879c950c22SSeongJae Park if (r->ar.end != next->ar.start) { 1889c950c22SSeongJae Park newr = damon_new_region(r->ar.end, next->ar.start); 1899c950c22SSeongJae Park if (!newr) 1909c950c22SSeongJae Park return -ENOMEM; 1919c950c22SSeongJae Park damon_insert_region(newr, r, next, t); 1929c950c22SSeongJae Park } 1939c950c22SSeongJae Park } 1949c950c22SSeongJae Park return 0; 1959c950c22SSeongJae Park } 1969c950c22SSeongJae Park 1979c950c22SSeongJae Park /* 198d0723bc0SSeongJae Park * damon_set_regions() - Set regions of a target for given address ranges. 199d0723bc0SSeongJae Park * @t: the given target. 200d0723bc0SSeongJae Park * @ranges: array of new monitoring target ranges. 201d0723bc0SSeongJae Park * @nr_ranges: length of @ranges. 202d0723bc0SSeongJae Park * 203d0723bc0SSeongJae Park * This function adds new regions to, or modify existing regions of a 204d0723bc0SSeongJae Park * monitoring target to fit in specific ranges. 205d0723bc0SSeongJae Park * 206d0723bc0SSeongJae Park * Return: 0 if success, or negative error code otherwise. 207d0723bc0SSeongJae Park */ 208d0723bc0SSeongJae Park int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, 209d0723bc0SSeongJae Park unsigned int nr_ranges) 210d0723bc0SSeongJae Park { 211d0723bc0SSeongJae Park struct damon_region *r, *next; 212d0723bc0SSeongJae Park unsigned int i; 2139c950c22SSeongJae Park int err; 214d0723bc0SSeongJae Park 215d0723bc0SSeongJae Park /* Remove regions which are not in the new ranges */ 216d0723bc0SSeongJae Park damon_for_each_region_safe(r, next, t) { 217d0723bc0SSeongJae Park for (i = 0; i < nr_ranges; i++) { 218d0723bc0SSeongJae Park if (damon_intersect(r, &ranges[i])) 219d0723bc0SSeongJae Park break; 220d0723bc0SSeongJae Park } 221d0723bc0SSeongJae Park if (i == nr_ranges) 222d0723bc0SSeongJae Park damon_destroy_region(r, t); 223d0723bc0SSeongJae Park } 224d0723bc0SSeongJae Park 22536001cbaSKaixu Xia r = damon_first_region(t); 226d0723bc0SSeongJae Park /* Add new regions or resize existing regions to fit in the ranges */ 227d0723bc0SSeongJae Park for (i = 0; i < nr_ranges; i++) { 228d0723bc0SSeongJae Park struct damon_region *first = NULL, *last, *newr; 229d0723bc0SSeongJae Park struct damon_addr_range *range; 230d0723bc0SSeongJae Park 231d0723bc0SSeongJae Park range = &ranges[i]; 232d0723bc0SSeongJae Park /* Get the first/last regions intersecting with the range */ 23336001cbaSKaixu Xia damon_for_each_region_from(r, t) { 234d0723bc0SSeongJae Park if (damon_intersect(r, range)) { 235d0723bc0SSeongJae Park if (!first) 236d0723bc0SSeongJae Park first = r; 237d0723bc0SSeongJae Park last = r; 238d0723bc0SSeongJae Park } 239d0723bc0SSeongJae Park if (r->ar.start >= range->end) 240d0723bc0SSeongJae Park break; 241d0723bc0SSeongJae Park } 242d0723bc0SSeongJae Park if (!first) { 243d0723bc0SSeongJae Park /* no region intersects with this range */ 244d0723bc0SSeongJae Park newr = damon_new_region( 245d0723bc0SSeongJae Park ALIGN_DOWN(range->start, 246d0723bc0SSeongJae Park DAMON_MIN_REGION), 247d0723bc0SSeongJae Park ALIGN(range->end, DAMON_MIN_REGION)); 248d0723bc0SSeongJae Park if (!newr) 249d0723bc0SSeongJae Park return -ENOMEM; 250d0723bc0SSeongJae Park damon_insert_region(newr, damon_prev_region(r), r, t); 251d0723bc0SSeongJae Park } else { 252d0723bc0SSeongJae Park /* resize intersecting regions to fit in this range */ 253d0723bc0SSeongJae Park first->ar.start = ALIGN_DOWN(range->start, 254d0723bc0SSeongJae Park DAMON_MIN_REGION); 255d0723bc0SSeongJae Park last->ar.end = ALIGN(range->end, DAMON_MIN_REGION); 2569c950c22SSeongJae Park 2579c950c22SSeongJae Park /* fill possible holes in the range */ 2589c950c22SSeongJae Park err = damon_fill_regions_holes(first, last, t); 2599c950c22SSeongJae Park if (err) 2609c950c22SSeongJae Park return err; 261d0723bc0SSeongJae Park } 262d0723bc0SSeongJae Park } 263d0723bc0SSeongJae Park return 0; 264d0723bc0SSeongJae Park } 265d0723bc0SSeongJae Park 26698def236SSeongJae Park struct damos_filter *damos_new_filter(enum damos_filter_type type, 26798def236SSeongJae Park bool matching) 26898def236SSeongJae Park { 26998def236SSeongJae Park struct damos_filter *filter; 27098def236SSeongJae Park 27198def236SSeongJae Park filter = kmalloc(sizeof(*filter), GFP_KERNEL); 27298def236SSeongJae Park if (!filter) 27398def236SSeongJae Park return NULL; 27498def236SSeongJae Park filter->type = type; 27598def236SSeongJae Park filter->matching = matching; 276*5f1fc67fSSeongJae Park INIT_LIST_HEAD(&filter->list); 27798def236SSeongJae Park return filter; 27898def236SSeongJae Park } 27998def236SSeongJae Park 28098def236SSeongJae Park void damos_add_filter(struct damos *s, struct damos_filter *f) 28198def236SSeongJae Park { 28298def236SSeongJae Park list_add_tail(&f->list, &s->filters); 28398def236SSeongJae Park } 28498def236SSeongJae Park 28598def236SSeongJae Park static void damos_del_filter(struct damos_filter *f) 28698def236SSeongJae Park { 28798def236SSeongJae Park list_del(&f->list); 28898def236SSeongJae Park } 28998def236SSeongJae Park 29098def236SSeongJae Park static void damos_free_filter(struct damos_filter *f) 29198def236SSeongJae Park { 29298def236SSeongJae Park kfree(f); 29398def236SSeongJae Park } 29498def236SSeongJae Park 29598def236SSeongJae Park void damos_destroy_filter(struct damos_filter *f) 29698def236SSeongJae Park { 29798def236SSeongJae Park damos_del_filter(f); 29898def236SSeongJae Park damos_free_filter(f); 29998def236SSeongJae Park } 30098def236SSeongJae Park 30170e0c1d1SSeongJae Park /* initialize private fields of damos_quota and return the pointer */ 30270e0c1d1SSeongJae Park static struct damos_quota *damos_quota_init_priv(struct damos_quota *quota) 30370e0c1d1SSeongJae Park { 30470e0c1d1SSeongJae Park quota->total_charged_sz = 0; 30570e0c1d1SSeongJae Park quota->total_charged_ns = 0; 30670e0c1d1SSeongJae Park quota->esz = 0; 30770e0c1d1SSeongJae Park quota->charged_sz = 0; 30870e0c1d1SSeongJae Park quota->charged_from = 0; 30970e0c1d1SSeongJae Park quota->charge_target_from = NULL; 31070e0c1d1SSeongJae Park quota->charge_addr_from = 0; 31170e0c1d1SSeongJae Park return quota; 31270e0c1d1SSeongJae Park } 31370e0c1d1SSeongJae Park 314f5a79d7cSYajun Deng struct damos *damon_new_scheme(struct damos_access_pattern *pattern, 315ee801b7dSSeongJae Park enum damos_action action, struct damos_quota *quota, 316ee801b7dSSeongJae Park struct damos_watermarks *wmarks) 3171f366e42SSeongJae Park { 3181f366e42SSeongJae Park struct damos *scheme; 3191f366e42SSeongJae Park 3201f366e42SSeongJae Park scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); 3211f366e42SSeongJae Park if (!scheme) 3221f366e42SSeongJae Park return NULL; 32302f17037SSeongJae Park scheme->pattern = *pattern; 3241f366e42SSeongJae Park scheme->action = action; 32598def236SSeongJae Park INIT_LIST_HEAD(&scheme->filters); 3260e92c2eeSSeongJae Park scheme->stat = (struct damos_stat){}; 3271f366e42SSeongJae Park INIT_LIST_HEAD(&scheme->list); 3281f366e42SSeongJae Park 32970e0c1d1SSeongJae Park scheme->quota = *(damos_quota_init_priv(quota)); 3302b8a248dSSeongJae Park 33102f17037SSeongJae Park scheme->wmarks = *wmarks; 332ee801b7dSSeongJae Park scheme->wmarks.activated = true; 333ee801b7dSSeongJae Park 3341f366e42SSeongJae Park return scheme; 3351f366e42SSeongJae Park } 3361f366e42SSeongJae Park 3371f366e42SSeongJae Park void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) 3381f366e42SSeongJae Park { 3391f366e42SSeongJae Park list_add_tail(&s->list, &ctx->schemes); 3401f366e42SSeongJae Park } 3411f366e42SSeongJae Park 3421f366e42SSeongJae Park static void damon_del_scheme(struct damos *s) 3431f366e42SSeongJae Park { 3441f366e42SSeongJae Park list_del(&s->list); 3451f366e42SSeongJae Park } 3461f366e42SSeongJae Park 3471f366e42SSeongJae Park static void damon_free_scheme(struct damos *s) 3481f366e42SSeongJae Park { 3491f366e42SSeongJae Park kfree(s); 3501f366e42SSeongJae Park } 3511f366e42SSeongJae Park 3521f366e42SSeongJae Park void damon_destroy_scheme(struct damos *s) 3531f366e42SSeongJae Park { 35498def236SSeongJae Park struct damos_filter *f, *next; 35598def236SSeongJae Park 35698def236SSeongJae Park damos_for_each_filter_safe(f, next, s) 35798def236SSeongJae Park damos_destroy_filter(f); 3581f366e42SSeongJae Park damon_del_scheme(s); 3591f366e42SSeongJae Park damon_free_scheme(s); 3601f366e42SSeongJae Park } 3611f366e42SSeongJae Park 362f23b8eeeSSeongJae Park /* 363f23b8eeeSSeongJae Park * Construct a damon_target struct 364f23b8eeeSSeongJae Park * 365f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 366f23b8eeeSSeongJae Park */ 3671971bd63SSeongJae Park struct damon_target *damon_new_target(void) 368f23b8eeeSSeongJae Park { 369f23b8eeeSSeongJae Park struct damon_target *t; 370f23b8eeeSSeongJae Park 371f23b8eeeSSeongJae Park t = kmalloc(sizeof(*t), GFP_KERNEL); 372f23b8eeeSSeongJae Park if (!t) 373f23b8eeeSSeongJae Park return NULL; 374f23b8eeeSSeongJae Park 3751971bd63SSeongJae Park t->pid = NULL; 376b9a6ac4eSSeongJae Park t->nr_regions = 0; 377f23b8eeeSSeongJae Park INIT_LIST_HEAD(&t->regions_list); 378b1f44cdaSSeongJae Park INIT_LIST_HEAD(&t->list); 379f23b8eeeSSeongJae Park 380f23b8eeeSSeongJae Park return t; 381f23b8eeeSSeongJae Park } 382f23b8eeeSSeongJae Park 383f23b8eeeSSeongJae Park void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) 384f23b8eeeSSeongJae Park { 385b9a6ac4eSSeongJae Park list_add_tail(&t->list, &ctx->adaptive_targets); 386f23b8eeeSSeongJae Park } 387f23b8eeeSSeongJae Park 388b5ca3e83SXin Hao bool damon_targets_empty(struct damon_ctx *ctx) 389b5ca3e83SXin Hao { 390b5ca3e83SXin Hao return list_empty(&ctx->adaptive_targets); 391b5ca3e83SXin Hao } 392b5ca3e83SXin Hao 393f23b8eeeSSeongJae Park static void damon_del_target(struct damon_target *t) 394f23b8eeeSSeongJae Park { 395f23b8eeeSSeongJae Park list_del(&t->list); 396f23b8eeeSSeongJae Park } 397f23b8eeeSSeongJae Park 398f23b8eeeSSeongJae Park void damon_free_target(struct damon_target *t) 399f23b8eeeSSeongJae Park { 400f23b8eeeSSeongJae Park struct damon_region *r, *next; 401f23b8eeeSSeongJae Park 402f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 403f23b8eeeSSeongJae Park damon_free_region(r); 404f23b8eeeSSeongJae Park kfree(t); 405f23b8eeeSSeongJae Park } 406f23b8eeeSSeongJae Park 407f23b8eeeSSeongJae Park void damon_destroy_target(struct damon_target *t) 408f23b8eeeSSeongJae Park { 409f23b8eeeSSeongJae Park damon_del_target(t); 410f23b8eeeSSeongJae Park damon_free_target(t); 411f23b8eeeSSeongJae Park } 412f23b8eeeSSeongJae Park 413b9a6ac4eSSeongJae Park unsigned int damon_nr_regions(struct damon_target *t) 414b9a6ac4eSSeongJae Park { 415b9a6ac4eSSeongJae Park return t->nr_regions; 416b9a6ac4eSSeongJae Park } 417b9a6ac4eSSeongJae Park 4182224d848SSeongJae Park struct damon_ctx *damon_new_ctx(void) 4192224d848SSeongJae Park { 4202224d848SSeongJae Park struct damon_ctx *ctx; 4212224d848SSeongJae Park 4222224d848SSeongJae Park ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 4232224d848SSeongJae Park if (!ctx) 4242224d848SSeongJae Park return NULL; 4252224d848SSeongJae Park 426cbeaa77bSSeongJae Park ctx->attrs.sample_interval = 5 * 1000; 427cbeaa77bSSeongJae Park ctx->attrs.aggr_interval = 100 * 1000; 428cbeaa77bSSeongJae Park ctx->attrs.ops_update_interval = 60 * 1000 * 1000; 4292224d848SSeongJae Park 4302224d848SSeongJae Park ktime_get_coarse_ts64(&ctx->last_aggregation); 431f7d911c3SSeongJae Park ctx->last_ops_update = ctx->last_aggregation; 4322224d848SSeongJae Park 4332224d848SSeongJae Park mutex_init(&ctx->kdamond_lock); 4342224d848SSeongJae Park 435cbeaa77bSSeongJae Park ctx->attrs.min_nr_regions = 10; 436cbeaa77bSSeongJae Park ctx->attrs.max_nr_regions = 1000; 437b9a6ac4eSSeongJae Park 438b9a6ac4eSSeongJae Park INIT_LIST_HEAD(&ctx->adaptive_targets); 4391f366e42SSeongJae Park INIT_LIST_HEAD(&ctx->schemes); 4402224d848SSeongJae Park 4412224d848SSeongJae Park return ctx; 4422224d848SSeongJae Park } 4432224d848SSeongJae Park 444f23b8eeeSSeongJae Park static void damon_destroy_targets(struct damon_ctx *ctx) 445f23b8eeeSSeongJae Park { 446f23b8eeeSSeongJae Park struct damon_target *t, *next_t; 447f23b8eeeSSeongJae Park 448f7d911c3SSeongJae Park if (ctx->ops.cleanup) { 449f7d911c3SSeongJae Park ctx->ops.cleanup(ctx); 450f23b8eeeSSeongJae Park return; 451f23b8eeeSSeongJae Park } 452f23b8eeeSSeongJae Park 453f23b8eeeSSeongJae Park damon_for_each_target_safe(t, next_t, ctx) 454f23b8eeeSSeongJae Park damon_destroy_target(t); 455f23b8eeeSSeongJae Park } 456f23b8eeeSSeongJae Park 4572224d848SSeongJae Park void damon_destroy_ctx(struct damon_ctx *ctx) 4582224d848SSeongJae Park { 4591f366e42SSeongJae Park struct damos *s, *next_s; 4601f366e42SSeongJae Park 461f23b8eeeSSeongJae Park damon_destroy_targets(ctx); 4621f366e42SSeongJae Park 4631f366e42SSeongJae Park damon_for_each_scheme_safe(s, next_s, ctx) 4641f366e42SSeongJae Park damon_destroy_scheme(s); 4651f366e42SSeongJae Park 4662224d848SSeongJae Park kfree(ctx); 4672224d848SSeongJae Park } 4682224d848SSeongJae Park 4692f5bef5aSSeongJae Park static unsigned int damon_age_for_new_attrs(unsigned int age, 4702f5bef5aSSeongJae Park struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) 4712f5bef5aSSeongJae Park { 4722f5bef5aSSeongJae Park return age * old_attrs->aggr_interval / new_attrs->aggr_interval; 4732f5bef5aSSeongJae Park } 4742f5bef5aSSeongJae Park 4752f5bef5aSSeongJae Park /* convert access ratio in bp (per 10,000) to nr_accesses */ 4762f5bef5aSSeongJae Park static unsigned int damon_accesses_bp_to_nr_accesses( 4772f5bef5aSSeongJae Park unsigned int accesses_bp, struct damon_attrs *attrs) 4782f5bef5aSSeongJae Park { 4792f5bef5aSSeongJae Park unsigned int max_nr_accesses = 4802f5bef5aSSeongJae Park attrs->aggr_interval / attrs->sample_interval; 4812f5bef5aSSeongJae Park 4822f5bef5aSSeongJae Park return accesses_bp * max_nr_accesses / 10000; 4832f5bef5aSSeongJae Park } 4842f5bef5aSSeongJae Park 4852f5bef5aSSeongJae Park /* convert nr_accesses to access ratio in bp (per 10,000) */ 4862f5bef5aSSeongJae Park static unsigned int damon_nr_accesses_to_accesses_bp( 4872f5bef5aSSeongJae Park unsigned int nr_accesses, struct damon_attrs *attrs) 4882f5bef5aSSeongJae Park { 4892f5bef5aSSeongJae Park unsigned int max_nr_accesses = 4902f5bef5aSSeongJae Park attrs->aggr_interval / attrs->sample_interval; 4912f5bef5aSSeongJae Park 4922f5bef5aSSeongJae Park return nr_accesses * 10000 / max_nr_accesses; 4932f5bef5aSSeongJae Park } 4942f5bef5aSSeongJae Park 4952f5bef5aSSeongJae Park static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses, 4962f5bef5aSSeongJae Park struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) 4972f5bef5aSSeongJae Park { 4982f5bef5aSSeongJae Park return damon_accesses_bp_to_nr_accesses( 4992f5bef5aSSeongJae Park damon_nr_accesses_to_accesses_bp( 5002f5bef5aSSeongJae Park nr_accesses, old_attrs), 5012f5bef5aSSeongJae Park new_attrs); 5022f5bef5aSSeongJae Park } 5032f5bef5aSSeongJae Park 5042f5bef5aSSeongJae Park static void damon_update_monitoring_result(struct damon_region *r, 5052f5bef5aSSeongJae Park struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) 5062f5bef5aSSeongJae Park { 5072f5bef5aSSeongJae Park r->nr_accesses = damon_nr_accesses_for_new_attrs(r->nr_accesses, 5082f5bef5aSSeongJae Park old_attrs, new_attrs); 5092f5bef5aSSeongJae Park r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs); 5102f5bef5aSSeongJae Park } 5112f5bef5aSSeongJae Park 5122f5bef5aSSeongJae Park /* 5132f5bef5aSSeongJae Park * region->nr_accesses is the number of sampling intervals in the last 5142f5bef5aSSeongJae Park * aggregation interval that access to the region has found, and region->age is 5152f5bef5aSSeongJae Park * the number of aggregation intervals that its access pattern has maintained. 5162f5bef5aSSeongJae Park * For the reason, the real meaning of the two fields depend on current 5172f5bef5aSSeongJae Park * sampling interval and aggregation interval. This function updates 5182f5bef5aSSeongJae Park * ->nr_accesses and ->age of given damon_ctx's regions for new damon_attrs. 5192f5bef5aSSeongJae Park */ 5202f5bef5aSSeongJae Park static void damon_update_monitoring_results(struct damon_ctx *ctx, 5212f5bef5aSSeongJae Park struct damon_attrs *new_attrs) 5222f5bef5aSSeongJae Park { 5232f5bef5aSSeongJae Park struct damon_attrs *old_attrs = &ctx->attrs; 5242f5bef5aSSeongJae Park struct damon_target *t; 5252f5bef5aSSeongJae Park struct damon_region *r; 5262f5bef5aSSeongJae Park 5272f5bef5aSSeongJae Park /* if any interval is zero, simply forgive conversion */ 5282f5bef5aSSeongJae Park if (!old_attrs->sample_interval || !old_attrs->aggr_interval || 5292f5bef5aSSeongJae Park !new_attrs->sample_interval || 5302f5bef5aSSeongJae Park !new_attrs->aggr_interval) 5312f5bef5aSSeongJae Park return; 5322f5bef5aSSeongJae Park 5332f5bef5aSSeongJae Park damon_for_each_target(t, ctx) 5342f5bef5aSSeongJae Park damon_for_each_region(r, t) 5352f5bef5aSSeongJae Park damon_update_monitoring_result( 5362f5bef5aSSeongJae Park r, old_attrs, new_attrs); 5372f5bef5aSSeongJae Park } 5382f5bef5aSSeongJae Park 5392224d848SSeongJae Park /** 5402224d848SSeongJae Park * damon_set_attrs() - Set attributes for the monitoring. 5412224d848SSeongJae Park * @ctx: monitoring context 542bead3b00SSeongJae Park * @attrs: monitoring attributes 5432224d848SSeongJae Park * 5442224d848SSeongJae Park * This function should not be called while the kdamond is running. 5452224d848SSeongJae Park * Every time interval is in micro-seconds. 5462224d848SSeongJae Park * 5472224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 5482224d848SSeongJae Park */ 549bead3b00SSeongJae Park int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs) 5502224d848SSeongJae Park { 551bead3b00SSeongJae Park if (attrs->min_nr_regions < 3) 552b9a6ac4eSSeongJae Park return -EINVAL; 553bead3b00SSeongJae Park if (attrs->min_nr_regions > attrs->max_nr_regions) 554b9a6ac4eSSeongJae Park return -EINVAL; 5555ff6e2ffSKefeng Wang if (attrs->sample_interval > attrs->aggr_interval) 5565ff6e2ffSKefeng Wang return -EINVAL; 557b9a6ac4eSSeongJae Park 5582f5bef5aSSeongJae Park damon_update_monitoring_results(ctx, attrs); 559bead3b00SSeongJae Park ctx->attrs = *attrs; 5602224d848SSeongJae Park return 0; 5612224d848SSeongJae Park } 5622224d848SSeongJae Park 5634bc05954SSeongJae Park /** 5641f366e42SSeongJae Park * damon_set_schemes() - Set data access monitoring based operation schemes. 5651f366e42SSeongJae Park * @ctx: monitoring context 5661f366e42SSeongJae Park * @schemes: array of the schemes 5671f366e42SSeongJae Park * @nr_schemes: number of entries in @schemes 5681f366e42SSeongJae Park * 5691f366e42SSeongJae Park * This function should not be called while the kdamond of the context is 5701f366e42SSeongJae Park * running. 5711f366e42SSeongJae Park */ 572cc713520SKaixu Xia void damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, 5731f366e42SSeongJae Park ssize_t nr_schemes) 5741f366e42SSeongJae Park { 5751f366e42SSeongJae Park struct damos *s, *next; 5761f366e42SSeongJae Park ssize_t i; 5771f366e42SSeongJae Park 5781f366e42SSeongJae Park damon_for_each_scheme_safe(s, next, ctx) 5791f366e42SSeongJae Park damon_destroy_scheme(s); 5801f366e42SSeongJae Park for (i = 0; i < nr_schemes; i++) 5811f366e42SSeongJae Park damon_add_scheme(ctx, schemes[i]); 5821f366e42SSeongJae Park } 5831f366e42SSeongJae Park 5841f366e42SSeongJae Park /** 5854bc05954SSeongJae Park * damon_nr_running_ctxs() - Return number of currently running contexts. 5864bc05954SSeongJae Park */ 5874bc05954SSeongJae Park int damon_nr_running_ctxs(void) 5884bc05954SSeongJae Park { 5894bc05954SSeongJae Park int nr_ctxs; 5904bc05954SSeongJae Park 5914bc05954SSeongJae Park mutex_lock(&damon_lock); 5924bc05954SSeongJae Park nr_ctxs = nr_running_ctxs; 5934bc05954SSeongJae Park mutex_unlock(&damon_lock); 5944bc05954SSeongJae Park 5954bc05954SSeongJae Park return nr_ctxs; 5964bc05954SSeongJae Park } 5974bc05954SSeongJae Park 598b9a6ac4eSSeongJae Park /* Returns the size upper limit for each monitoring region */ 599b9a6ac4eSSeongJae Park static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) 600b9a6ac4eSSeongJae Park { 601b9a6ac4eSSeongJae Park struct damon_target *t; 602b9a6ac4eSSeongJae Park struct damon_region *r; 603b9a6ac4eSSeongJae Park unsigned long sz = 0; 604b9a6ac4eSSeongJae Park 605b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) { 606b9a6ac4eSSeongJae Park damon_for_each_region(r, t) 607ab63f63fSXin Hao sz += damon_sz_region(r); 608b9a6ac4eSSeongJae Park } 609b9a6ac4eSSeongJae Park 610cbeaa77bSSeongJae Park if (ctx->attrs.min_nr_regions) 611cbeaa77bSSeongJae Park sz /= ctx->attrs.min_nr_regions; 612b9a6ac4eSSeongJae Park if (sz < DAMON_MIN_REGION) 613b9a6ac4eSSeongJae Park sz = DAMON_MIN_REGION; 614b9a6ac4eSSeongJae Park 615b9a6ac4eSSeongJae Park return sz; 616b9a6ac4eSSeongJae Park } 617b9a6ac4eSSeongJae Park 6182224d848SSeongJae Park static int kdamond_fn(void *data); 6192224d848SSeongJae Park 6202224d848SSeongJae Park /* 6212224d848SSeongJae Park * __damon_start() - Starts monitoring with given context. 6222224d848SSeongJae Park * @ctx: monitoring context 6232224d848SSeongJae Park * 6242224d848SSeongJae Park * This function should be called while damon_lock is hold. 6252224d848SSeongJae Park * 6262224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 6272224d848SSeongJae Park */ 6282224d848SSeongJae Park static int __damon_start(struct damon_ctx *ctx) 6292224d848SSeongJae Park { 6302224d848SSeongJae Park int err = -EBUSY; 6312224d848SSeongJae Park 6322224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 6332224d848SSeongJae Park if (!ctx->kdamond) { 6342224d848SSeongJae Park err = 0; 6352224d848SSeongJae Park ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", 6362224d848SSeongJae Park nr_running_ctxs); 6372224d848SSeongJae Park if (IS_ERR(ctx->kdamond)) { 6382224d848SSeongJae Park err = PTR_ERR(ctx->kdamond); 6397ec1992bSColin Ian King ctx->kdamond = NULL; 6402224d848SSeongJae Park } 6412224d848SSeongJae Park } 6422224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 6432224d848SSeongJae Park 6442224d848SSeongJae Park return err; 6452224d848SSeongJae Park } 6462224d848SSeongJae Park 6472224d848SSeongJae Park /** 6482224d848SSeongJae Park * damon_start() - Starts the monitorings for a given group of contexts. 6492224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to start monitoring 6502224d848SSeongJae Park * @nr_ctxs: size of @ctxs 6518b9b0d33SSeongJae Park * @exclusive: exclusiveness of this contexts group 6522224d848SSeongJae Park * 6532224d848SSeongJae Park * This function starts a group of monitoring threads for a group of monitoring 6542224d848SSeongJae Park * contexts. One thread per each context is created and run in parallel. The 6558b9b0d33SSeongJae Park * caller should handle synchronization between the threads by itself. If 6568b9b0d33SSeongJae Park * @exclusive is true and a group of threads that created by other 6578b9b0d33SSeongJae Park * 'damon_start()' call is currently running, this function does nothing but 6588b9b0d33SSeongJae Park * returns -EBUSY. 6592224d848SSeongJae Park * 6602224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 6612224d848SSeongJae Park */ 6628b9b0d33SSeongJae Park int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive) 6632224d848SSeongJae Park { 6642224d848SSeongJae Park int i; 6652224d848SSeongJae Park int err = 0; 6662224d848SSeongJae Park 6672224d848SSeongJae Park mutex_lock(&damon_lock); 6688b9b0d33SSeongJae Park if ((exclusive && nr_running_ctxs) || 6698b9b0d33SSeongJae Park (!exclusive && running_exclusive_ctxs)) { 6702224d848SSeongJae Park mutex_unlock(&damon_lock); 6712224d848SSeongJae Park return -EBUSY; 6722224d848SSeongJae Park } 6732224d848SSeongJae Park 6742224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 6752224d848SSeongJae Park err = __damon_start(ctxs[i]); 6762224d848SSeongJae Park if (err) 6772224d848SSeongJae Park break; 6782224d848SSeongJae Park nr_running_ctxs++; 6792224d848SSeongJae Park } 6808b9b0d33SSeongJae Park if (exclusive && nr_running_ctxs) 6818b9b0d33SSeongJae Park running_exclusive_ctxs = true; 6822224d848SSeongJae Park mutex_unlock(&damon_lock); 6832224d848SSeongJae Park 6842224d848SSeongJae Park return err; 6852224d848SSeongJae Park } 6862224d848SSeongJae Park 6872224d848SSeongJae Park /* 6888b9b0d33SSeongJae Park * __damon_stop() - Stops monitoring of a given context. 6892224d848SSeongJae Park * @ctx: monitoring context 6902224d848SSeongJae Park * 6912224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 6922224d848SSeongJae Park */ 6932224d848SSeongJae Park static int __damon_stop(struct damon_ctx *ctx) 6942224d848SSeongJae Park { 6950f91d133SChangbin Du struct task_struct *tsk; 6960f91d133SChangbin Du 6972224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 6980f91d133SChangbin Du tsk = ctx->kdamond; 6990f91d133SChangbin Du if (tsk) { 7000f91d133SChangbin Du get_task_struct(tsk); 7012224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 7020f91d133SChangbin Du kthread_stop(tsk); 7030f91d133SChangbin Du put_task_struct(tsk); 7042224d848SSeongJae Park return 0; 7052224d848SSeongJae Park } 7062224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 7072224d848SSeongJae Park 7082224d848SSeongJae Park return -EPERM; 7092224d848SSeongJae Park } 7102224d848SSeongJae Park 7112224d848SSeongJae Park /** 7122224d848SSeongJae Park * damon_stop() - Stops the monitorings for a given group of contexts. 7132224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to stop monitoring 7142224d848SSeongJae Park * @nr_ctxs: size of @ctxs 7152224d848SSeongJae Park * 7162224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 7172224d848SSeongJae Park */ 7182224d848SSeongJae Park int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) 7192224d848SSeongJae Park { 7202224d848SSeongJae Park int i, err = 0; 7212224d848SSeongJae Park 7222224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 7232224d848SSeongJae Park /* nr_running_ctxs is decremented in kdamond_fn */ 7242224d848SSeongJae Park err = __damon_stop(ctxs[i]); 7252224d848SSeongJae Park if (err) 7268b9b0d33SSeongJae Park break; 7272224d848SSeongJae Park } 7282224d848SSeongJae Park return err; 7292224d848SSeongJae Park } 7302224d848SSeongJae Park 7312224d848SSeongJae Park /* 7322224d848SSeongJae Park * damon_check_reset_time_interval() - Check if a time interval is elapsed. 7332224d848SSeongJae Park * @baseline: the time to check whether the interval has elapsed since 7342224d848SSeongJae Park * @interval: the time interval (microseconds) 7352224d848SSeongJae Park * 7362224d848SSeongJae Park * See whether the given time interval has passed since the given baseline 7372224d848SSeongJae Park * time. If so, it also updates the baseline to current time for next check. 7382224d848SSeongJae Park * 7392224d848SSeongJae Park * Return: true if the time interval has passed, or false otherwise. 7402224d848SSeongJae Park */ 7412224d848SSeongJae Park static bool damon_check_reset_time_interval(struct timespec64 *baseline, 7422224d848SSeongJae Park unsigned long interval) 7432224d848SSeongJae Park { 7442224d848SSeongJae Park struct timespec64 now; 7452224d848SSeongJae Park 7462224d848SSeongJae Park ktime_get_coarse_ts64(&now); 7472224d848SSeongJae Park if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) < 7482224d848SSeongJae Park interval * 1000) 7492224d848SSeongJae Park return false; 7502224d848SSeongJae Park *baseline = now; 7512224d848SSeongJae Park return true; 7522224d848SSeongJae Park } 7532224d848SSeongJae Park 7542224d848SSeongJae Park /* 7552224d848SSeongJae Park * Check whether it is time to flush the aggregated information 7562224d848SSeongJae Park */ 7572224d848SSeongJae Park static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) 7582224d848SSeongJae Park { 7592224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_aggregation, 760cbeaa77bSSeongJae Park ctx->attrs.aggr_interval); 7612224d848SSeongJae Park } 7622224d848SSeongJae Park 7632224d848SSeongJae Park /* 764f23b8eeeSSeongJae Park * Reset the aggregated monitoring results ('nr_accesses' of each region). 765f23b8eeeSSeongJae Park */ 766f23b8eeeSSeongJae Park static void kdamond_reset_aggregated(struct damon_ctx *c) 767f23b8eeeSSeongJae Park { 768f23b8eeeSSeongJae Park struct damon_target *t; 76976fd0285SSeongJae Park unsigned int ti = 0; /* target's index */ 770f23b8eeeSSeongJae Park 771f23b8eeeSSeongJae Park damon_for_each_target(t, c) { 772f23b8eeeSSeongJae Park struct damon_region *r; 773f23b8eeeSSeongJae Park 7742fcb9362SSeongJae Park damon_for_each_region(r, t) { 77576fd0285SSeongJae Park trace_damon_aggregated(t, ti, r, damon_nr_regions(t)); 776fda504faSSeongJae Park r->last_nr_accesses = r->nr_accesses; 777f23b8eeeSSeongJae Park r->nr_accesses = 0; 778f23b8eeeSSeongJae Park } 77976fd0285SSeongJae Park ti++; 780f23b8eeeSSeongJae Park } 7812fcb9362SSeongJae Park } 782f23b8eeeSSeongJae Park 7834ed98243SKaixu Xia static void damon_split_region_at(struct damon_target *t, 7844ed98243SKaixu Xia struct damon_region *r, unsigned long sz_r); 7852b8a248dSSeongJae Park 78638683e00SSeongJae Park static bool __damos_valid_target(struct damon_region *r, struct damos *s) 78738683e00SSeongJae Park { 78838683e00SSeongJae Park unsigned long sz; 78938683e00SSeongJae Park 790ab63f63fSXin Hao sz = damon_sz_region(r); 791f5a79d7cSYajun Deng return s->pattern.min_sz_region <= sz && 792f5a79d7cSYajun Deng sz <= s->pattern.max_sz_region && 793f5a79d7cSYajun Deng s->pattern.min_nr_accesses <= r->nr_accesses && 794f5a79d7cSYajun Deng r->nr_accesses <= s->pattern.max_nr_accesses && 795f5a79d7cSYajun Deng s->pattern.min_age_region <= r->age && 796f5a79d7cSYajun Deng r->age <= s->pattern.max_age_region; 79738683e00SSeongJae Park } 79838683e00SSeongJae Park 79938683e00SSeongJae Park static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, 80038683e00SSeongJae Park struct damon_region *r, struct damos *s) 80138683e00SSeongJae Park { 80238683e00SSeongJae Park bool ret = __damos_valid_target(r, s); 80338683e00SSeongJae Park 804f7d911c3SSeongJae Park if (!ret || !s->quota.esz || !c->ops.get_scheme_score) 80538683e00SSeongJae Park return ret; 80638683e00SSeongJae Park 807f7d911c3SSeongJae Park return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; 80838683e00SSeongJae Park } 80938683e00SSeongJae Park 8102ea34989SSeongJae Park /* 8112ea34989SSeongJae Park * damos_skip_charged_region() - Check if the given region or starting part of 8122ea34989SSeongJae Park * it is already charged for the DAMOS quota. 8132ea34989SSeongJae Park * @t: The target of the region. 8142ea34989SSeongJae Park * @rp: The pointer to the region. 8152ea34989SSeongJae Park * @s: The scheme to be applied. 8162ea34989SSeongJae Park * 8172ea34989SSeongJae Park * If a quota of a scheme has exceeded in a quota charge window, the scheme's 8182ea34989SSeongJae Park * action would applied to only a part of the target access pattern fulfilling 8192ea34989SSeongJae Park * regions. To avoid applying the scheme action to only already applied 8202ea34989SSeongJae Park * regions, DAMON skips applying the scheme action to the regions that charged 8212ea34989SSeongJae Park * in the previous charge window. 8222ea34989SSeongJae Park * 8232ea34989SSeongJae Park * This function checks if a given region should be skipped or not for the 8242ea34989SSeongJae Park * reason. If only the starting part of the region has previously charged, 8252ea34989SSeongJae Park * this function splits the region into two so that the second one covers the 8262ea34989SSeongJae Park * area that not charged in the previous charge widnow and saves the second 8272ea34989SSeongJae Park * region in *rp and returns false, so that the caller can apply DAMON action 8282ea34989SSeongJae Park * to the second one. 8292ea34989SSeongJae Park * 8302ea34989SSeongJae Park * Return: true if the region should be entirely skipped, false otherwise. 8312ea34989SSeongJae Park */ 8322ea34989SSeongJae Park static bool damos_skip_charged_region(struct damon_target *t, 8332ea34989SSeongJae Park struct damon_region **rp, struct damos *s) 8342ea34989SSeongJae Park { 8352ea34989SSeongJae Park struct damon_region *r = *rp; 8362ea34989SSeongJae Park struct damos_quota *quota = &s->quota; 8372ea34989SSeongJae Park unsigned long sz_to_skip; 8382ea34989SSeongJae Park 8392ea34989SSeongJae Park /* Skip previously charged regions */ 8402ea34989SSeongJae Park if (quota->charge_target_from) { 8412ea34989SSeongJae Park if (t != quota->charge_target_from) 8422ea34989SSeongJae Park return true; 8432ea34989SSeongJae Park if (r == damon_last_region(t)) { 8442ea34989SSeongJae Park quota->charge_target_from = NULL; 8452ea34989SSeongJae Park quota->charge_addr_from = 0; 8462ea34989SSeongJae Park return true; 8472ea34989SSeongJae Park } 8482ea34989SSeongJae Park if (quota->charge_addr_from && 8492ea34989SSeongJae Park r->ar.end <= quota->charge_addr_from) 8502ea34989SSeongJae Park return true; 8512ea34989SSeongJae Park 8522ea34989SSeongJae Park if (quota->charge_addr_from && r->ar.start < 8532ea34989SSeongJae Park quota->charge_addr_from) { 8542ea34989SSeongJae Park sz_to_skip = ALIGN_DOWN(quota->charge_addr_from - 8552ea34989SSeongJae Park r->ar.start, DAMON_MIN_REGION); 8562ea34989SSeongJae Park if (!sz_to_skip) { 8572ea34989SSeongJae Park if (damon_sz_region(r) <= DAMON_MIN_REGION) 8582ea34989SSeongJae Park return true; 8592ea34989SSeongJae Park sz_to_skip = DAMON_MIN_REGION; 8602ea34989SSeongJae Park } 8612ea34989SSeongJae Park damon_split_region_at(t, r, sz_to_skip); 8622ea34989SSeongJae Park r = damon_next_region(r); 8632ea34989SSeongJae Park *rp = r; 8642ea34989SSeongJae Park } 8652ea34989SSeongJae Park quota->charge_target_from = NULL; 8662ea34989SSeongJae Park quota->charge_addr_from = 0; 8672ea34989SSeongJae Park } 8682ea34989SSeongJae Park return false; 8692ea34989SSeongJae Park } 8702ea34989SSeongJae Park 871d1cbbf62SSeongJae Park static void damos_update_stat(struct damos *s, 872d1cbbf62SSeongJae Park unsigned long sz_tried, unsigned long sz_applied) 873d1cbbf62SSeongJae Park { 874d1cbbf62SSeongJae Park s->stat.nr_tried++; 875d1cbbf62SSeongJae Park s->stat.sz_tried += sz_tried; 876d1cbbf62SSeongJae Park if (sz_applied) 877d1cbbf62SSeongJae Park s->stat.nr_applied++; 878d1cbbf62SSeongJae Park s->stat.sz_applied += sz_applied; 879d1cbbf62SSeongJae Park } 880d1cbbf62SSeongJae Park 881e63a30c5SSeongJae Park static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, 882e63a30c5SSeongJae Park struct damon_region *r, struct damos *s) 8831f366e42SSeongJae Park { 8842b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 885e63a30c5SSeongJae Park unsigned long sz = damon_sz_region(r); 8861cd24303SSeongJae Park struct timespec64 begin, end; 8870e92c2eeSSeongJae Park unsigned long sz_applied = 0; 88844467bbbSSeongJae Park int err = 0; 8892b8a248dSSeongJae Park 890f7d911c3SSeongJae Park if (c->ops.apply_scheme) { 891e63a30c5SSeongJae Park if (quota->esz && quota->charged_sz + sz > quota->esz) { 8921cd24303SSeongJae Park sz = ALIGN_DOWN(quota->esz - quota->charged_sz, 8932b8a248dSSeongJae Park DAMON_MIN_REGION); 8942b8a248dSSeongJae Park if (!sz) 8952b8a248dSSeongJae Park goto update_stat; 8964ed98243SKaixu Xia damon_split_region_at(t, r, sz); 8972b8a248dSSeongJae Park } 8981cd24303SSeongJae Park ktime_get_coarse_ts64(&begin); 89944467bbbSSeongJae Park if (c->callback.before_damos_apply) 90044467bbbSSeongJae Park err = c->callback.before_damos_apply(c, t, r, s); 90144467bbbSSeongJae Park if (!err) 902f7d911c3SSeongJae Park sz_applied = c->ops.apply_scheme(c, t, r, s); 9031cd24303SSeongJae Park ktime_get_coarse_ts64(&end); 9041cd24303SSeongJae Park quota->total_charged_ns += timespec64_to_ns(&end) - 9051cd24303SSeongJae Park timespec64_to_ns(&begin); 9062b8a248dSSeongJae Park quota->charged_sz += sz; 9071cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) { 90850585192SSeongJae Park quota->charge_target_from = t; 90950585192SSeongJae Park quota->charge_addr_from = r->ar.end + 1; 91050585192SSeongJae Park } 9112b8a248dSSeongJae Park } 9122f0b548cSSeongJae Park if (s->action != DAMOS_STAT) 9131f366e42SSeongJae Park r->age = 0; 9142b8a248dSSeongJae Park 9152b8a248dSSeongJae Park update_stat: 916d1cbbf62SSeongJae Park damos_update_stat(s, sz, sz_applied); 9171f366e42SSeongJae Park } 918e63a30c5SSeongJae Park 919e63a30c5SSeongJae Park static void damon_do_apply_schemes(struct damon_ctx *c, 920e63a30c5SSeongJae Park struct damon_target *t, 921e63a30c5SSeongJae Park struct damon_region *r) 922e63a30c5SSeongJae Park { 923e63a30c5SSeongJae Park struct damos *s; 924e63a30c5SSeongJae Park 925e63a30c5SSeongJae Park damon_for_each_scheme(s, c) { 926e63a30c5SSeongJae Park struct damos_quota *quota = &s->quota; 927e63a30c5SSeongJae Park 928e63a30c5SSeongJae Park if (!s->wmarks.activated) 929e63a30c5SSeongJae Park continue; 930e63a30c5SSeongJae Park 931e63a30c5SSeongJae Park /* Check the quota */ 932e63a30c5SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 933e63a30c5SSeongJae Park continue; 934e63a30c5SSeongJae Park 935e63a30c5SSeongJae Park if (damos_skip_charged_region(t, &r, s)) 936e63a30c5SSeongJae Park continue; 937e63a30c5SSeongJae Park 938e63a30c5SSeongJae Park if (!damos_valid_target(c, t, r, s)) 939e63a30c5SSeongJae Park continue; 940e63a30c5SSeongJae Park 941e63a30c5SSeongJae Park damos_apply_scheme(c, t, r, s); 942e63a30c5SSeongJae Park } 9431f366e42SSeongJae Park } 9441f366e42SSeongJae Park 9451cd24303SSeongJae Park /* Shouldn't be called if quota->ms and quota->sz are zero */ 9461cd24303SSeongJae Park static void damos_set_effective_quota(struct damos_quota *quota) 9471cd24303SSeongJae Park { 9481cd24303SSeongJae Park unsigned long throughput; 9491cd24303SSeongJae Park unsigned long esz; 9501cd24303SSeongJae Park 9511cd24303SSeongJae Park if (!quota->ms) { 9521cd24303SSeongJae Park quota->esz = quota->sz; 9531cd24303SSeongJae Park return; 9541cd24303SSeongJae Park } 9551cd24303SSeongJae Park 9561cd24303SSeongJae Park if (quota->total_charged_ns) 9571cd24303SSeongJae Park throughput = quota->total_charged_sz * 1000000 / 9581cd24303SSeongJae Park quota->total_charged_ns; 9591cd24303SSeongJae Park else 9601cd24303SSeongJae Park throughput = PAGE_SIZE * 1024; 9611cd24303SSeongJae Park esz = throughput * quota->ms; 9621cd24303SSeongJae Park 9631cd24303SSeongJae Park if (quota->sz && quota->sz < esz) 9641cd24303SSeongJae Park esz = quota->sz; 9651cd24303SSeongJae Park quota->esz = esz; 9661cd24303SSeongJae Park } 9671cd24303SSeongJae Park 968898810e5SSeongJae Park static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) 9691f366e42SSeongJae Park { 9702b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 971898810e5SSeongJae Park struct damon_target *t; 972898810e5SSeongJae Park struct damon_region *r; 97338683e00SSeongJae Park unsigned long cumulated_sz; 97438683e00SSeongJae Park unsigned int score, max_score = 0; 9752b8a248dSSeongJae Park 9761cd24303SSeongJae Park if (!quota->ms && !quota->sz) 977898810e5SSeongJae Park return; 9782b8a248dSSeongJae Park 9792b8a248dSSeongJae Park /* New charge window starts */ 9802b8a248dSSeongJae Park if (time_after_eq(jiffies, quota->charged_from + 981898810e5SSeongJae Park msecs_to_jiffies(quota->reset_interval))) { 9826268eac3SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 9836268eac3SSeongJae Park s->stat.qt_exceeds++; 9841cd24303SSeongJae Park quota->total_charged_sz += quota->charged_sz; 9852b8a248dSSeongJae Park quota->charged_from = jiffies; 9862b8a248dSSeongJae Park quota->charged_sz = 0; 9871cd24303SSeongJae Park damos_set_effective_quota(quota); 9882b8a248dSSeongJae Park } 98938683e00SSeongJae Park 990f7d911c3SSeongJae Park if (!c->ops.get_scheme_score) 991898810e5SSeongJae Park return; 99238683e00SSeongJae Park 99338683e00SSeongJae Park /* Fill up the score histogram */ 99438683e00SSeongJae Park memset(quota->histogram, 0, sizeof(quota->histogram)); 99538683e00SSeongJae Park damon_for_each_target(t, c) { 99638683e00SSeongJae Park damon_for_each_region(r, t) { 99738683e00SSeongJae Park if (!__damos_valid_target(r, s)) 99838683e00SSeongJae Park continue; 999898810e5SSeongJae Park score = c->ops.get_scheme_score(c, t, r, s); 1000ab63f63fSXin Hao quota->histogram[score] += damon_sz_region(r); 100138683e00SSeongJae Park if (score > max_score) 100238683e00SSeongJae Park max_score = score; 100338683e00SSeongJae Park } 100438683e00SSeongJae Park } 100538683e00SSeongJae Park 100638683e00SSeongJae Park /* Set the min score limit */ 100738683e00SSeongJae Park for (cumulated_sz = 0, score = max_score; ; score--) { 100838683e00SSeongJae Park cumulated_sz += quota->histogram[score]; 100938683e00SSeongJae Park if (cumulated_sz >= quota->esz || !score) 101038683e00SSeongJae Park break; 101138683e00SSeongJae Park } 101238683e00SSeongJae Park quota->min_score = score; 10132b8a248dSSeongJae Park } 10141f366e42SSeongJae Park 1015898810e5SSeongJae Park static void kdamond_apply_schemes(struct damon_ctx *c) 1016898810e5SSeongJae Park { 1017898810e5SSeongJae Park struct damon_target *t; 1018898810e5SSeongJae Park struct damon_region *r, *next_r; 1019898810e5SSeongJae Park struct damos *s; 1020898810e5SSeongJae Park 1021898810e5SSeongJae Park damon_for_each_scheme(s, c) { 1022898810e5SSeongJae Park if (!s->wmarks.activated) 1023898810e5SSeongJae Park continue; 1024898810e5SSeongJae Park 1025898810e5SSeongJae Park damos_adjust_quota(c, s); 1026898810e5SSeongJae Park } 1027898810e5SSeongJae Park 10281f366e42SSeongJae Park damon_for_each_target(t, c) { 10292b8a248dSSeongJae Park damon_for_each_region_safe(r, next_r, t) 10301f366e42SSeongJae Park damon_do_apply_schemes(c, t, r); 10311f366e42SSeongJae Park } 10321f366e42SSeongJae Park } 10331f366e42SSeongJae Park 1034b9a6ac4eSSeongJae Park /* 1035b9a6ac4eSSeongJae Park * Merge two adjacent regions into one region 1036b9a6ac4eSSeongJae Park */ 1037b9a6ac4eSSeongJae Park static void damon_merge_two_regions(struct damon_target *t, 1038b9a6ac4eSSeongJae Park struct damon_region *l, struct damon_region *r) 1039b9a6ac4eSSeongJae Park { 1040652e0446SXin Hao unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r); 1041b9a6ac4eSSeongJae Park 1042b9a6ac4eSSeongJae Park l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / 1043b9a6ac4eSSeongJae Park (sz_l + sz_r); 1044fda504faSSeongJae Park l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); 1045b9a6ac4eSSeongJae Park l->ar.end = r->ar.end; 1046b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 1047b9a6ac4eSSeongJae Park } 1048b9a6ac4eSSeongJae Park 1049b9a6ac4eSSeongJae Park /* 1050b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 1051b9a6ac4eSSeongJae Park * 1052b9a6ac4eSSeongJae Park * t target affected by this merge operation 1053b9a6ac4eSSeongJae Park * thres '->nr_accesses' diff threshold for the merge 1054b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 1055b9a6ac4eSSeongJae Park */ 1056b9a6ac4eSSeongJae Park static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, 1057b9a6ac4eSSeongJae Park unsigned long sz_limit) 1058b9a6ac4eSSeongJae Park { 1059b9a6ac4eSSeongJae Park struct damon_region *r, *prev = NULL, *next; 1060b9a6ac4eSSeongJae Park 1061b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 1062d720bbbdSXin Hao if (abs(r->nr_accesses - r->last_nr_accesses) > thres) 1063fda504faSSeongJae Park r->age = 0; 1064fda504faSSeongJae Park else 1065fda504faSSeongJae Park r->age++; 1066fda504faSSeongJae Park 1067b9a6ac4eSSeongJae Park if (prev && prev->ar.end == r->ar.start && 1068d720bbbdSXin Hao abs(prev->nr_accesses - r->nr_accesses) <= thres && 1069652e0446SXin Hao damon_sz_region(prev) + damon_sz_region(r) <= sz_limit) 1070b9a6ac4eSSeongJae Park damon_merge_two_regions(t, prev, r); 1071b9a6ac4eSSeongJae Park else 1072b9a6ac4eSSeongJae Park prev = r; 1073b9a6ac4eSSeongJae Park } 1074b9a6ac4eSSeongJae Park } 1075b9a6ac4eSSeongJae Park 1076b9a6ac4eSSeongJae Park /* 1077b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 1078b9a6ac4eSSeongJae Park * 1079b9a6ac4eSSeongJae Park * threshold '->nr_accesses' diff threshold for the merge 1080b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 1081b9a6ac4eSSeongJae Park * 1082b9a6ac4eSSeongJae Park * This function merges monitoring target regions which are adjacent and their 1083b9a6ac4eSSeongJae Park * access frequencies are similar. This is for minimizing the monitoring 1084b9a6ac4eSSeongJae Park * overhead under the dynamically changeable access pattern. If a merge was 1085b9a6ac4eSSeongJae Park * unnecessarily made, later 'kdamond_split_regions()' will revert it. 1086b9a6ac4eSSeongJae Park */ 1087b9a6ac4eSSeongJae Park static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, 1088b9a6ac4eSSeongJae Park unsigned long sz_limit) 1089b9a6ac4eSSeongJae Park { 1090b9a6ac4eSSeongJae Park struct damon_target *t; 1091b9a6ac4eSSeongJae Park 1092b9a6ac4eSSeongJae Park damon_for_each_target(t, c) 1093b9a6ac4eSSeongJae Park damon_merge_regions_of(t, threshold, sz_limit); 1094b9a6ac4eSSeongJae Park } 1095b9a6ac4eSSeongJae Park 1096b9a6ac4eSSeongJae Park /* 1097b9a6ac4eSSeongJae Park * Split a region in two 1098b9a6ac4eSSeongJae Park * 1099b9a6ac4eSSeongJae Park * r the region to be split 1100b9a6ac4eSSeongJae Park * sz_r size of the first sub-region that will be made 1101b9a6ac4eSSeongJae Park */ 11024ed98243SKaixu Xia static void damon_split_region_at(struct damon_target *t, 11034ed98243SKaixu Xia struct damon_region *r, unsigned long sz_r) 1104b9a6ac4eSSeongJae Park { 1105b9a6ac4eSSeongJae Park struct damon_region *new; 1106b9a6ac4eSSeongJae Park 1107b9a6ac4eSSeongJae Park new = damon_new_region(r->ar.start + sz_r, r->ar.end); 1108b9a6ac4eSSeongJae Park if (!new) 1109b9a6ac4eSSeongJae Park return; 1110b9a6ac4eSSeongJae Park 1111b9a6ac4eSSeongJae Park r->ar.end = new->ar.start; 1112b9a6ac4eSSeongJae Park 1113fda504faSSeongJae Park new->age = r->age; 1114fda504faSSeongJae Park new->last_nr_accesses = r->last_nr_accesses; 1115fda504faSSeongJae Park 1116b9a6ac4eSSeongJae Park damon_insert_region(new, r, damon_next_region(r), t); 1117b9a6ac4eSSeongJae Park } 1118b9a6ac4eSSeongJae Park 1119b9a6ac4eSSeongJae Park /* Split every region in the given target into 'nr_subs' regions */ 11204ed98243SKaixu Xia static void damon_split_regions_of(struct damon_target *t, int nr_subs) 1121b9a6ac4eSSeongJae Park { 1122b9a6ac4eSSeongJae Park struct damon_region *r, *next; 1123b9a6ac4eSSeongJae Park unsigned long sz_region, sz_sub = 0; 1124b9a6ac4eSSeongJae Park int i; 1125b9a6ac4eSSeongJae Park 1126b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 1127ab63f63fSXin Hao sz_region = damon_sz_region(r); 1128b9a6ac4eSSeongJae Park 1129b9a6ac4eSSeongJae Park for (i = 0; i < nr_subs - 1 && 1130b9a6ac4eSSeongJae Park sz_region > 2 * DAMON_MIN_REGION; i++) { 1131b9a6ac4eSSeongJae Park /* 1132b9a6ac4eSSeongJae Park * Randomly select size of left sub-region to be at 1133b9a6ac4eSSeongJae Park * least 10 percent and at most 90% of original region 1134b9a6ac4eSSeongJae Park */ 1135b9a6ac4eSSeongJae Park sz_sub = ALIGN_DOWN(damon_rand(1, 10) * 1136b9a6ac4eSSeongJae Park sz_region / 10, DAMON_MIN_REGION); 1137b9a6ac4eSSeongJae Park /* Do not allow blank region */ 1138b9a6ac4eSSeongJae Park if (sz_sub == 0 || sz_sub >= sz_region) 1139b9a6ac4eSSeongJae Park continue; 1140b9a6ac4eSSeongJae Park 11414ed98243SKaixu Xia damon_split_region_at(t, r, sz_sub); 1142b9a6ac4eSSeongJae Park sz_region = sz_sub; 1143b9a6ac4eSSeongJae Park } 1144b9a6ac4eSSeongJae Park } 1145b9a6ac4eSSeongJae Park } 1146b9a6ac4eSSeongJae Park 1147b9a6ac4eSSeongJae Park /* 1148b9a6ac4eSSeongJae Park * Split every target region into randomly-sized small regions 1149b9a6ac4eSSeongJae Park * 1150b9a6ac4eSSeongJae Park * This function splits every target region into random-sized small regions if 1151b9a6ac4eSSeongJae Park * current total number of the regions is equal or smaller than half of the 1152b9a6ac4eSSeongJae Park * user-specified maximum number of regions. This is for maximizing the 1153b9a6ac4eSSeongJae Park * monitoring accuracy under the dynamically changeable access patterns. If a 1154b9a6ac4eSSeongJae Park * split was unnecessarily made, later 'kdamond_merge_regions()' will revert 1155b9a6ac4eSSeongJae Park * it. 1156b9a6ac4eSSeongJae Park */ 1157b9a6ac4eSSeongJae Park static void kdamond_split_regions(struct damon_ctx *ctx) 1158b9a6ac4eSSeongJae Park { 1159b9a6ac4eSSeongJae Park struct damon_target *t; 1160b9a6ac4eSSeongJae Park unsigned int nr_regions = 0; 1161b9a6ac4eSSeongJae Park static unsigned int last_nr_regions; 1162b9a6ac4eSSeongJae Park int nr_subregions = 2; 1163b9a6ac4eSSeongJae Park 1164b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 1165b9a6ac4eSSeongJae Park nr_regions += damon_nr_regions(t); 1166b9a6ac4eSSeongJae Park 1167cbeaa77bSSeongJae Park if (nr_regions > ctx->attrs.max_nr_regions / 2) 1168b9a6ac4eSSeongJae Park return; 1169b9a6ac4eSSeongJae Park 1170b9a6ac4eSSeongJae Park /* Maybe the middle of the region has different access frequency */ 1171b9a6ac4eSSeongJae Park if (last_nr_regions == nr_regions && 1172cbeaa77bSSeongJae Park nr_regions < ctx->attrs.max_nr_regions / 3) 1173b9a6ac4eSSeongJae Park nr_subregions = 3; 1174b9a6ac4eSSeongJae Park 1175b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 11764ed98243SKaixu Xia damon_split_regions_of(t, nr_subregions); 1177b9a6ac4eSSeongJae Park 1178b9a6ac4eSSeongJae Park last_nr_regions = nr_regions; 1179b9a6ac4eSSeongJae Park } 1180b9a6ac4eSSeongJae Park 1181f23b8eeeSSeongJae Park /* 1182f7d911c3SSeongJae Park * Check whether it is time to check and apply the operations-related data 1183f7d911c3SSeongJae Park * structures. 11842224d848SSeongJae Park * 11852224d848SSeongJae Park * Returns true if it is. 11862224d848SSeongJae Park */ 1187f7d911c3SSeongJae Park static bool kdamond_need_update_operations(struct damon_ctx *ctx) 11882224d848SSeongJae Park { 1189f7d911c3SSeongJae Park return damon_check_reset_time_interval(&ctx->last_ops_update, 1190cbeaa77bSSeongJae Park ctx->attrs.ops_update_interval); 11912224d848SSeongJae Park } 11922224d848SSeongJae Park 11932224d848SSeongJae Park /* 11942224d848SSeongJae Park * Check whether current monitoring should be stopped 11952224d848SSeongJae Park * 11962224d848SSeongJae Park * The monitoring is stopped when either the user requested to stop, or all 11972224d848SSeongJae Park * monitoring targets are invalid. 11982224d848SSeongJae Park * 11992224d848SSeongJae Park * Returns true if need to stop current monitoring. 12002224d848SSeongJae Park */ 12012224d848SSeongJae Park static bool kdamond_need_stop(struct damon_ctx *ctx) 12022224d848SSeongJae Park { 1203f23b8eeeSSeongJae Park struct damon_target *t; 12042224d848SSeongJae Park 12050f91d133SChangbin Du if (kthread_should_stop()) 12062224d848SSeongJae Park return true; 12072224d848SSeongJae Park 1208f7d911c3SSeongJae Park if (!ctx->ops.target_valid) 12092224d848SSeongJae Park return false; 12102224d848SSeongJae Park 1211f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 1212f7d911c3SSeongJae Park if (ctx->ops.target_valid(t)) 1213f23b8eeeSSeongJae Park return false; 1214f23b8eeeSSeongJae Park } 1215f23b8eeeSSeongJae Park 1216f23b8eeeSSeongJae Park return true; 12172224d848SSeongJae Park } 12182224d848SSeongJae Park 1219ee801b7dSSeongJae Park static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) 1220ee801b7dSSeongJae Park { 1221ee801b7dSSeongJae Park struct sysinfo i; 1222ee801b7dSSeongJae Park 1223ee801b7dSSeongJae Park switch (metric) { 1224ee801b7dSSeongJae Park case DAMOS_WMARK_FREE_MEM_RATE: 1225ee801b7dSSeongJae Park si_meminfo(&i); 1226ee801b7dSSeongJae Park return i.freeram * 1000 / i.totalram; 1227ee801b7dSSeongJae Park default: 1228ee801b7dSSeongJae Park break; 1229ee801b7dSSeongJae Park } 1230ee801b7dSSeongJae Park return -EINVAL; 1231ee801b7dSSeongJae Park } 1232ee801b7dSSeongJae Park 1233ee801b7dSSeongJae Park /* 1234ee801b7dSSeongJae Park * Returns zero if the scheme is active. Else, returns time to wait for next 1235ee801b7dSSeongJae Park * watermark check in micro-seconds. 1236ee801b7dSSeongJae Park */ 1237ee801b7dSSeongJae Park static unsigned long damos_wmark_wait_us(struct damos *scheme) 1238ee801b7dSSeongJae Park { 1239ee801b7dSSeongJae Park unsigned long metric; 1240ee801b7dSSeongJae Park 1241ee801b7dSSeongJae Park if (scheme->wmarks.metric == DAMOS_WMARK_NONE) 1242ee801b7dSSeongJae Park return 0; 1243ee801b7dSSeongJae Park 1244ee801b7dSSeongJae Park metric = damos_wmark_metric_value(scheme->wmarks.metric); 1245ee801b7dSSeongJae Park /* higher than high watermark or lower than low watermark */ 1246ee801b7dSSeongJae Park if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { 1247ee801b7dSSeongJae Park if (scheme->wmarks.activated) 124801078655SColin Ian King pr_debug("deactivate a scheme (%d) for %s wmark\n", 1249ee801b7dSSeongJae Park scheme->action, 1250ee801b7dSSeongJae Park metric > scheme->wmarks.high ? 1251ee801b7dSSeongJae Park "high" : "low"); 1252ee801b7dSSeongJae Park scheme->wmarks.activated = false; 1253ee801b7dSSeongJae Park return scheme->wmarks.interval; 1254ee801b7dSSeongJae Park } 1255ee801b7dSSeongJae Park 1256ee801b7dSSeongJae Park /* inactive and higher than middle watermark */ 1257ee801b7dSSeongJae Park if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && 1258ee801b7dSSeongJae Park !scheme->wmarks.activated) 1259ee801b7dSSeongJae Park return scheme->wmarks.interval; 1260ee801b7dSSeongJae Park 1261ee801b7dSSeongJae Park if (!scheme->wmarks.activated) 1262ee801b7dSSeongJae Park pr_debug("activate a scheme (%d)\n", scheme->action); 1263ee801b7dSSeongJae Park scheme->wmarks.activated = true; 1264ee801b7dSSeongJae Park return 0; 1265ee801b7dSSeongJae Park } 1266ee801b7dSSeongJae Park 1267ee801b7dSSeongJae Park static void kdamond_usleep(unsigned long usecs) 1268ee801b7dSSeongJae Park { 12694de46a30SSeongJae Park /* See Documentation/timers/timers-howto.rst for the thresholds */ 12704de46a30SSeongJae Park if (usecs > 20 * USEC_PER_MSEC) 127170e92748SSeongJae Park schedule_timeout_idle(usecs_to_jiffies(usecs)); 1272ee801b7dSSeongJae Park else 127370e92748SSeongJae Park usleep_idle_range(usecs, usecs + 1); 1274ee801b7dSSeongJae Park } 1275ee801b7dSSeongJae Park 1276ee801b7dSSeongJae Park /* Returns negative error code if it's not activated but should return */ 1277ee801b7dSSeongJae Park static int kdamond_wait_activation(struct damon_ctx *ctx) 1278ee801b7dSSeongJae Park { 1279ee801b7dSSeongJae Park struct damos *s; 1280ee801b7dSSeongJae Park unsigned long wait_time; 1281ee801b7dSSeongJae Park unsigned long min_wait_time = 0; 128278049e94SJonghyeon Kim bool init_wait_time = false; 1283ee801b7dSSeongJae Park 1284ee801b7dSSeongJae Park while (!kdamond_need_stop(ctx)) { 1285ee801b7dSSeongJae Park damon_for_each_scheme(s, ctx) { 1286ee801b7dSSeongJae Park wait_time = damos_wmark_wait_us(s); 128778049e94SJonghyeon Kim if (!init_wait_time || wait_time < min_wait_time) { 128878049e94SJonghyeon Kim init_wait_time = true; 1289ee801b7dSSeongJae Park min_wait_time = wait_time; 1290ee801b7dSSeongJae Park } 129178049e94SJonghyeon Kim } 1292ee801b7dSSeongJae Park if (!min_wait_time) 1293ee801b7dSSeongJae Park return 0; 1294ee801b7dSSeongJae Park 1295ee801b7dSSeongJae Park kdamond_usleep(min_wait_time); 12966e74d2bfSSeongJae Park 12976e74d2bfSSeongJae Park if (ctx->callback.after_wmarks_check && 12986e74d2bfSSeongJae Park ctx->callback.after_wmarks_check(ctx)) 12996e74d2bfSSeongJae Park break; 1300ee801b7dSSeongJae Park } 1301ee801b7dSSeongJae Park return -EBUSY; 1302ee801b7dSSeongJae Park } 1303ee801b7dSSeongJae Park 13042224d848SSeongJae Park /* 13052224d848SSeongJae Park * The monitoring daemon that runs as a kernel thread 13062224d848SSeongJae Park */ 13072224d848SSeongJae Park static int kdamond_fn(void *data) 13082224d848SSeongJae Park { 1309cef4493fSYu Zhe struct damon_ctx *ctx = data; 1310f23b8eeeSSeongJae Park struct damon_target *t; 1311f23b8eeeSSeongJae Park struct damon_region *r, *next; 1312b9a6ac4eSSeongJae Park unsigned int max_nr_accesses = 0; 1313b9a6ac4eSSeongJae Park unsigned long sz_limit = 0; 13142224d848SSeongJae Park 131542e4cef5SChangbin Du pr_debug("kdamond (%d) starts\n", current->pid); 13162224d848SSeongJae Park 1317f7d911c3SSeongJae Park if (ctx->ops.init) 1318f7d911c3SSeongJae Park ctx->ops.init(ctx); 13192224d848SSeongJae Park if (ctx->callback.before_start && ctx->callback.before_start(ctx)) 132029454cf6SKaixu Xia goto done; 13212224d848SSeongJae Park 1322b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 1323b9a6ac4eSSeongJae Park 132429454cf6SKaixu Xia while (!kdamond_need_stop(ctx)) { 132529454cf6SKaixu Xia if (kdamond_wait_activation(ctx)) 132629454cf6SKaixu Xia break; 1327ee801b7dSSeongJae Park 1328f7d911c3SSeongJae Park if (ctx->ops.prepare_access_checks) 1329f7d911c3SSeongJae Park ctx->ops.prepare_access_checks(ctx); 13302224d848SSeongJae Park if (ctx->callback.after_sampling && 133129454cf6SKaixu Xia ctx->callback.after_sampling(ctx)) 133229454cf6SKaixu Xia break; 13332224d848SSeongJae Park 1334cbeaa77bSSeongJae Park kdamond_usleep(ctx->attrs.sample_interval); 13352224d848SSeongJae Park 1336f7d911c3SSeongJae Park if (ctx->ops.check_accesses) 1337f7d911c3SSeongJae Park max_nr_accesses = ctx->ops.check_accesses(ctx); 13382224d848SSeongJae Park 13392224d848SSeongJae Park if (kdamond_aggregate_interval_passed(ctx)) { 1340b9a6ac4eSSeongJae Park kdamond_merge_regions(ctx, 1341b9a6ac4eSSeongJae Park max_nr_accesses / 10, 1342b9a6ac4eSSeongJae Park sz_limit); 13432224d848SSeongJae Park if (ctx->callback.after_aggregation && 134429454cf6SKaixu Xia ctx->callback.after_aggregation(ctx)) 134529454cf6SKaixu Xia break; 134664517d6eSHuaisheng Ye if (!list_empty(&ctx->schemes)) 13471f366e42SSeongJae Park kdamond_apply_schemes(ctx); 1348f23b8eeeSSeongJae Park kdamond_reset_aggregated(ctx); 1349b9a6ac4eSSeongJae Park kdamond_split_regions(ctx); 1350f7d911c3SSeongJae Park if (ctx->ops.reset_aggregated) 1351f7d911c3SSeongJae Park ctx->ops.reset_aggregated(ctx); 13522224d848SSeongJae Park } 13532224d848SSeongJae Park 1354f7d911c3SSeongJae Park if (kdamond_need_update_operations(ctx)) { 1355f7d911c3SSeongJae Park if (ctx->ops.update) 1356f7d911c3SSeongJae Park ctx->ops.update(ctx); 1357b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 13582224d848SSeongJae Park } 13592224d848SSeongJae Park } 136029454cf6SKaixu Xia done: 1361f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 1362f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 1363b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 1364f23b8eeeSSeongJae Park } 13652224d848SSeongJae Park 13660f91d133SChangbin Du if (ctx->callback.before_terminate) 13670f91d133SChangbin Du ctx->callback.before_terminate(ctx); 1368f7d911c3SSeongJae Park if (ctx->ops.cleanup) 1369f7d911c3SSeongJae Park ctx->ops.cleanup(ctx); 13702224d848SSeongJae Park 137142e4cef5SChangbin Du pr_debug("kdamond (%d) finishes\n", current->pid); 13722224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 13732224d848SSeongJae Park ctx->kdamond = NULL; 13742224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 13752224d848SSeongJae Park 13762224d848SSeongJae Park mutex_lock(&damon_lock); 13772224d848SSeongJae Park nr_running_ctxs--; 13788b9b0d33SSeongJae Park if (!nr_running_ctxs && running_exclusive_ctxs) 13798b9b0d33SSeongJae Park running_exclusive_ctxs = false; 13802224d848SSeongJae Park mutex_unlock(&damon_lock); 13812224d848SSeongJae Park 13825f7fe2b9SChangbin Du return 0; 13832224d848SSeongJae Park } 138417ccae8bSSeongJae Park 13850d83b2d8SXin Hao /* 13860d83b2d8SXin Hao * struct damon_system_ram_region - System RAM resource address region of 13870d83b2d8SXin Hao * [@start, @end). 13880d83b2d8SXin Hao * @start: Start address of the region (inclusive). 13890d83b2d8SXin Hao * @end: End address of the region (exclusive). 13900d83b2d8SXin Hao */ 13910d83b2d8SXin Hao struct damon_system_ram_region { 13920d83b2d8SXin Hao unsigned long start; 13930d83b2d8SXin Hao unsigned long end; 13940d83b2d8SXin Hao }; 13950d83b2d8SXin Hao 13960d83b2d8SXin Hao static int walk_system_ram(struct resource *res, void *arg) 13970d83b2d8SXin Hao { 13980d83b2d8SXin Hao struct damon_system_ram_region *a = arg; 13990d83b2d8SXin Hao 14000d83b2d8SXin Hao if (a->end - a->start < resource_size(res)) { 14010d83b2d8SXin Hao a->start = res->start; 14020d83b2d8SXin Hao a->end = res->end; 14030d83b2d8SXin Hao } 14040d83b2d8SXin Hao return 0; 14050d83b2d8SXin Hao } 14060d83b2d8SXin Hao 14070d83b2d8SXin Hao /* 14080d83b2d8SXin Hao * Find biggest 'System RAM' resource and store its start and end address in 14090d83b2d8SXin Hao * @start and @end, respectively. If no System RAM is found, returns false. 14100d83b2d8SXin Hao */ 1411233f0b31SKaixu Xia static bool damon_find_biggest_system_ram(unsigned long *start, 1412233f0b31SKaixu Xia unsigned long *end) 14130d83b2d8SXin Hao 14140d83b2d8SXin Hao { 14150d83b2d8SXin Hao struct damon_system_ram_region arg = {}; 14160d83b2d8SXin Hao 14170d83b2d8SXin Hao walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram); 14180d83b2d8SXin Hao if (arg.end <= arg.start) 14190d83b2d8SXin Hao return false; 14200d83b2d8SXin Hao 14210d83b2d8SXin Hao *start = arg.start; 14220d83b2d8SXin Hao *end = arg.end; 14230d83b2d8SXin Hao return true; 14240d83b2d8SXin Hao } 14250d83b2d8SXin Hao 1426233f0b31SKaixu Xia /** 1427233f0b31SKaixu Xia * damon_set_region_biggest_system_ram_default() - Set the region of the given 1428233f0b31SKaixu Xia * monitoring target as requested, or biggest 'System RAM'. 1429233f0b31SKaixu Xia * @t: The monitoring target to set the region. 1430233f0b31SKaixu Xia * @start: The pointer to the start address of the region. 1431233f0b31SKaixu Xia * @end: The pointer to the end address of the region. 1432233f0b31SKaixu Xia * 1433233f0b31SKaixu Xia * This function sets the region of @t as requested by @start and @end. If the 1434233f0b31SKaixu Xia * values of @start and @end are zero, however, this function finds the biggest 1435233f0b31SKaixu Xia * 'System RAM' resource and sets the region to cover the resource. In the 1436233f0b31SKaixu Xia * latter case, this function saves the start and end addresses of the resource 1437233f0b31SKaixu Xia * in @start and @end, respectively. 1438233f0b31SKaixu Xia * 1439233f0b31SKaixu Xia * Return: 0 on success, negative error code otherwise. 1440233f0b31SKaixu Xia */ 1441233f0b31SKaixu Xia int damon_set_region_biggest_system_ram_default(struct damon_target *t, 1442233f0b31SKaixu Xia unsigned long *start, unsigned long *end) 1443233f0b31SKaixu Xia { 1444233f0b31SKaixu Xia struct damon_addr_range addr_range; 1445233f0b31SKaixu Xia 1446233f0b31SKaixu Xia if (*start > *end) 1447233f0b31SKaixu Xia return -EINVAL; 1448233f0b31SKaixu Xia 1449233f0b31SKaixu Xia if (!*start && !*end && 1450233f0b31SKaixu Xia !damon_find_biggest_system_ram(start, end)) 1451233f0b31SKaixu Xia return -EINVAL; 1452233f0b31SKaixu Xia 1453233f0b31SKaixu Xia addr_range.start = *start; 1454233f0b31SKaixu Xia addr_range.end = *end; 1455233f0b31SKaixu Xia return damon_set_regions(t, &addr_range, 1); 1456233f0b31SKaixu Xia } 1457233f0b31SKaixu Xia 1458a1870944SDawei Li static int __init damon_init(void) 1459a1870944SDawei Li { 1460a1870944SDawei Li damon_region_cache = KMEM_CACHE(damon_region, 0); 1461a1870944SDawei Li if (unlikely(!damon_region_cache)) { 1462a1870944SDawei Li pr_err("creating damon_region_cache fails\n"); 1463a1870944SDawei Li return -ENOMEM; 1464a1870944SDawei Li } 1465a1870944SDawei Li 1466a1870944SDawei Li return 0; 1467a1870944SDawei Li } 1468a1870944SDawei Li 1469a1870944SDawei Li subsys_initcall(damon_init); 1470a1870944SDawei Li 147117ccae8bSSeongJae Park #include "core-test.h" 1472