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> 14b9a6ac4eSSeongJae Park #include <linux/random.h> 152224d848SSeongJae Park #include <linux/slab.h> 1638683e00SSeongJae Park #include <linux/string.h> 172224d848SSeongJae Park 182fcb9362SSeongJae Park #define CREATE_TRACE_POINTS 192fcb9362SSeongJae Park #include <trace/events/damon.h> 202fcb9362SSeongJae Park 2117ccae8bSSeongJae Park #ifdef CONFIG_DAMON_KUNIT_TEST 2217ccae8bSSeongJae Park #undef DAMON_MIN_REGION 2317ccae8bSSeongJae Park #define DAMON_MIN_REGION 1 2417ccae8bSSeongJae Park #endif 2517ccae8bSSeongJae Park 26b9a6ac4eSSeongJae Park /* Get a random number in [l, r) */ 27b9a6ac4eSSeongJae Park #define damon_rand(l, r) (l + prandom_u32_max(r - l)) 28b9a6ac4eSSeongJae Park 292224d848SSeongJae Park static DEFINE_MUTEX(damon_lock); 302224d848SSeongJae Park static int nr_running_ctxs; 312224d848SSeongJae Park 32f23b8eeeSSeongJae Park /* 33f23b8eeeSSeongJae Park * Construct a damon_region struct 34f23b8eeeSSeongJae Park * 35f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 36f23b8eeeSSeongJae Park */ 37f23b8eeeSSeongJae Park struct damon_region *damon_new_region(unsigned long start, unsigned long end) 38f23b8eeeSSeongJae Park { 39f23b8eeeSSeongJae Park struct damon_region *region; 40f23b8eeeSSeongJae Park 41f23b8eeeSSeongJae Park region = kmalloc(sizeof(*region), GFP_KERNEL); 42f23b8eeeSSeongJae Park if (!region) 43f23b8eeeSSeongJae Park return NULL; 44f23b8eeeSSeongJae Park 45f23b8eeeSSeongJae Park region->ar.start = start; 46f23b8eeeSSeongJae Park region->ar.end = end; 47f23b8eeeSSeongJae Park region->nr_accesses = 0; 48f23b8eeeSSeongJae Park INIT_LIST_HEAD(®ion->list); 49f23b8eeeSSeongJae Park 50fda504faSSeongJae Park region->age = 0; 51fda504faSSeongJae Park region->last_nr_accesses = 0; 52fda504faSSeongJae Park 53f23b8eeeSSeongJae Park return region; 54f23b8eeeSSeongJae Park } 55f23b8eeeSSeongJae Park 56f23b8eeeSSeongJae Park /* 57f23b8eeeSSeongJae Park * Add a region between two other regions 58f23b8eeeSSeongJae Park */ 59f23b8eeeSSeongJae Park inline void damon_insert_region(struct damon_region *r, 60b9a6ac4eSSeongJae Park struct damon_region *prev, struct damon_region *next, 61b9a6ac4eSSeongJae Park struct damon_target *t) 62f23b8eeeSSeongJae Park { 63f23b8eeeSSeongJae Park __list_add(&r->list, &prev->list, &next->list); 64b9a6ac4eSSeongJae Park t->nr_regions++; 65f23b8eeeSSeongJae Park } 66f23b8eeeSSeongJae Park 67f23b8eeeSSeongJae Park void damon_add_region(struct damon_region *r, struct damon_target *t) 68f23b8eeeSSeongJae Park { 69f23b8eeeSSeongJae Park list_add_tail(&r->list, &t->regions_list); 70b9a6ac4eSSeongJae Park t->nr_regions++; 71f23b8eeeSSeongJae Park } 72f23b8eeeSSeongJae Park 73b9a6ac4eSSeongJae Park static void damon_del_region(struct damon_region *r, struct damon_target *t) 74f23b8eeeSSeongJae Park { 75f23b8eeeSSeongJae Park list_del(&r->list); 76b9a6ac4eSSeongJae Park t->nr_regions--; 77f23b8eeeSSeongJae Park } 78f23b8eeeSSeongJae Park 79f23b8eeeSSeongJae Park static void damon_free_region(struct damon_region *r) 80f23b8eeeSSeongJae Park { 81f23b8eeeSSeongJae Park kfree(r); 82f23b8eeeSSeongJae Park } 83f23b8eeeSSeongJae Park 84b9a6ac4eSSeongJae Park void damon_destroy_region(struct damon_region *r, struct damon_target *t) 85f23b8eeeSSeongJae Park { 86b9a6ac4eSSeongJae Park damon_del_region(r, t); 87f23b8eeeSSeongJae Park damon_free_region(r); 88f23b8eeeSSeongJae Park } 89f23b8eeeSSeongJae Park 901f366e42SSeongJae Park struct damos *damon_new_scheme( 911f366e42SSeongJae Park unsigned long min_sz_region, unsigned long max_sz_region, 921f366e42SSeongJae Park unsigned int min_nr_accesses, unsigned int max_nr_accesses, 931f366e42SSeongJae Park unsigned int min_age_region, unsigned int max_age_region, 94ee801b7dSSeongJae Park enum damos_action action, struct damos_quota *quota, 95ee801b7dSSeongJae Park struct damos_watermarks *wmarks) 961f366e42SSeongJae Park { 971f366e42SSeongJae Park struct damos *scheme; 981f366e42SSeongJae Park 991f366e42SSeongJae Park scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); 1001f366e42SSeongJae Park if (!scheme) 1011f366e42SSeongJae Park return NULL; 1021f366e42SSeongJae Park scheme->min_sz_region = min_sz_region; 1031f366e42SSeongJae Park scheme->max_sz_region = max_sz_region; 1041f366e42SSeongJae Park scheme->min_nr_accesses = min_nr_accesses; 1051f366e42SSeongJae Park scheme->max_nr_accesses = max_nr_accesses; 1061f366e42SSeongJae Park scheme->min_age_region = min_age_region; 1071f366e42SSeongJae Park scheme->max_age_region = max_age_region; 1081f366e42SSeongJae Park scheme->action = action; 1092f0b548cSSeongJae Park scheme->stat_count = 0; 1102f0b548cSSeongJae Park scheme->stat_sz = 0; 1111f366e42SSeongJae Park INIT_LIST_HEAD(&scheme->list); 1121f366e42SSeongJae Park 1131cd24303SSeongJae Park scheme->quota.ms = quota->ms; 1142b8a248dSSeongJae Park scheme->quota.sz = quota->sz; 1152b8a248dSSeongJae Park scheme->quota.reset_interval = quota->reset_interval; 11638683e00SSeongJae Park scheme->quota.weight_sz = quota->weight_sz; 11738683e00SSeongJae Park scheme->quota.weight_nr_accesses = quota->weight_nr_accesses; 11838683e00SSeongJae Park scheme->quota.weight_age = quota->weight_age; 1191cd24303SSeongJae Park scheme->quota.total_charged_sz = 0; 1201cd24303SSeongJae Park scheme->quota.total_charged_ns = 0; 1211cd24303SSeongJae Park scheme->quota.esz = 0; 1222b8a248dSSeongJae Park scheme->quota.charged_sz = 0; 1232b8a248dSSeongJae Park scheme->quota.charged_from = 0; 12450585192SSeongJae Park scheme->quota.charge_target_from = NULL; 12550585192SSeongJae Park scheme->quota.charge_addr_from = 0; 1262b8a248dSSeongJae Park 127ee801b7dSSeongJae Park scheme->wmarks.metric = wmarks->metric; 128ee801b7dSSeongJae Park scheme->wmarks.interval = wmarks->interval; 129ee801b7dSSeongJae Park scheme->wmarks.high = wmarks->high; 130ee801b7dSSeongJae Park scheme->wmarks.mid = wmarks->mid; 131ee801b7dSSeongJae Park scheme->wmarks.low = wmarks->low; 132ee801b7dSSeongJae Park scheme->wmarks.activated = true; 133ee801b7dSSeongJae Park 1341f366e42SSeongJae Park return scheme; 1351f366e42SSeongJae Park } 1361f366e42SSeongJae Park 1371f366e42SSeongJae Park void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) 1381f366e42SSeongJae Park { 1391f366e42SSeongJae Park list_add_tail(&s->list, &ctx->schemes); 1401f366e42SSeongJae Park } 1411f366e42SSeongJae Park 1421f366e42SSeongJae Park static void damon_del_scheme(struct damos *s) 1431f366e42SSeongJae Park { 1441f366e42SSeongJae Park list_del(&s->list); 1451f366e42SSeongJae Park } 1461f366e42SSeongJae Park 1471f366e42SSeongJae Park static void damon_free_scheme(struct damos *s) 1481f366e42SSeongJae Park { 1491f366e42SSeongJae Park kfree(s); 1501f366e42SSeongJae Park } 1511f366e42SSeongJae Park 1521f366e42SSeongJae Park void damon_destroy_scheme(struct damos *s) 1531f366e42SSeongJae Park { 1541f366e42SSeongJae Park damon_del_scheme(s); 1551f366e42SSeongJae Park damon_free_scheme(s); 1561f366e42SSeongJae Park } 1571f366e42SSeongJae Park 158f23b8eeeSSeongJae Park /* 159f23b8eeeSSeongJae Park * Construct a damon_target struct 160f23b8eeeSSeongJae Park * 161f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 162f23b8eeeSSeongJae Park */ 163f23b8eeeSSeongJae Park struct damon_target *damon_new_target(unsigned long id) 164f23b8eeeSSeongJae Park { 165f23b8eeeSSeongJae Park struct damon_target *t; 166f23b8eeeSSeongJae Park 167f23b8eeeSSeongJae Park t = kmalloc(sizeof(*t), GFP_KERNEL); 168f23b8eeeSSeongJae Park if (!t) 169f23b8eeeSSeongJae Park return NULL; 170f23b8eeeSSeongJae Park 171f23b8eeeSSeongJae Park t->id = id; 172b9a6ac4eSSeongJae Park t->nr_regions = 0; 173f23b8eeeSSeongJae Park INIT_LIST_HEAD(&t->regions_list); 174f23b8eeeSSeongJae Park 175f23b8eeeSSeongJae Park return t; 176f23b8eeeSSeongJae Park } 177f23b8eeeSSeongJae Park 178f23b8eeeSSeongJae Park void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) 179f23b8eeeSSeongJae Park { 180b9a6ac4eSSeongJae Park list_add_tail(&t->list, &ctx->adaptive_targets); 181f23b8eeeSSeongJae Park } 182f23b8eeeSSeongJae Park 183b5ca3e83SXin Hao bool damon_targets_empty(struct damon_ctx *ctx) 184b5ca3e83SXin Hao { 185b5ca3e83SXin Hao return list_empty(&ctx->adaptive_targets); 186b5ca3e83SXin Hao } 187b5ca3e83SXin Hao 188f23b8eeeSSeongJae Park static void damon_del_target(struct damon_target *t) 189f23b8eeeSSeongJae Park { 190f23b8eeeSSeongJae Park list_del(&t->list); 191f23b8eeeSSeongJae Park } 192f23b8eeeSSeongJae Park 193f23b8eeeSSeongJae Park void damon_free_target(struct damon_target *t) 194f23b8eeeSSeongJae Park { 195f23b8eeeSSeongJae Park struct damon_region *r, *next; 196f23b8eeeSSeongJae Park 197f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 198f23b8eeeSSeongJae Park damon_free_region(r); 199f23b8eeeSSeongJae Park kfree(t); 200f23b8eeeSSeongJae Park } 201f23b8eeeSSeongJae Park 202f23b8eeeSSeongJae Park void damon_destroy_target(struct damon_target *t) 203f23b8eeeSSeongJae Park { 204f23b8eeeSSeongJae Park damon_del_target(t); 205f23b8eeeSSeongJae Park damon_free_target(t); 206f23b8eeeSSeongJae Park } 207f23b8eeeSSeongJae Park 208b9a6ac4eSSeongJae Park unsigned int damon_nr_regions(struct damon_target *t) 209b9a6ac4eSSeongJae Park { 210b9a6ac4eSSeongJae Park return t->nr_regions; 211b9a6ac4eSSeongJae Park } 212b9a6ac4eSSeongJae Park 2132224d848SSeongJae Park struct damon_ctx *damon_new_ctx(void) 2142224d848SSeongJae Park { 2152224d848SSeongJae Park struct damon_ctx *ctx; 2162224d848SSeongJae Park 2172224d848SSeongJae Park ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 2182224d848SSeongJae Park if (!ctx) 2192224d848SSeongJae Park return NULL; 2202224d848SSeongJae Park 2212224d848SSeongJae Park ctx->sample_interval = 5 * 1000; 2222224d848SSeongJae Park ctx->aggr_interval = 100 * 1000; 2232224d848SSeongJae Park ctx->primitive_update_interval = 60 * 1000 * 1000; 2242224d848SSeongJae Park 2252224d848SSeongJae Park ktime_get_coarse_ts64(&ctx->last_aggregation); 2262224d848SSeongJae Park ctx->last_primitive_update = ctx->last_aggregation; 2272224d848SSeongJae Park 2282224d848SSeongJae Park mutex_init(&ctx->kdamond_lock); 2292224d848SSeongJae Park 230b9a6ac4eSSeongJae Park ctx->min_nr_regions = 10; 231b9a6ac4eSSeongJae Park ctx->max_nr_regions = 1000; 232b9a6ac4eSSeongJae Park 233b9a6ac4eSSeongJae Park INIT_LIST_HEAD(&ctx->adaptive_targets); 2341f366e42SSeongJae Park INIT_LIST_HEAD(&ctx->schemes); 2352224d848SSeongJae Park 2362224d848SSeongJae Park return ctx; 2372224d848SSeongJae Park } 2382224d848SSeongJae Park 239f23b8eeeSSeongJae Park static void damon_destroy_targets(struct damon_ctx *ctx) 240f23b8eeeSSeongJae Park { 241f23b8eeeSSeongJae Park struct damon_target *t, *next_t; 242f23b8eeeSSeongJae Park 243f23b8eeeSSeongJae Park if (ctx->primitive.cleanup) { 244f23b8eeeSSeongJae Park ctx->primitive.cleanup(ctx); 245f23b8eeeSSeongJae Park return; 246f23b8eeeSSeongJae Park } 247f23b8eeeSSeongJae Park 248f23b8eeeSSeongJae Park damon_for_each_target_safe(t, next_t, ctx) 249f23b8eeeSSeongJae Park damon_destroy_target(t); 250f23b8eeeSSeongJae Park } 251f23b8eeeSSeongJae Park 2522224d848SSeongJae Park void damon_destroy_ctx(struct damon_ctx *ctx) 2532224d848SSeongJae Park { 2541f366e42SSeongJae Park struct damos *s, *next_s; 2551f366e42SSeongJae Park 256f23b8eeeSSeongJae Park damon_destroy_targets(ctx); 2571f366e42SSeongJae Park 2581f366e42SSeongJae Park damon_for_each_scheme_safe(s, next_s, ctx) 2591f366e42SSeongJae Park damon_destroy_scheme(s); 2601f366e42SSeongJae Park 2612224d848SSeongJae Park kfree(ctx); 2622224d848SSeongJae Park } 2632224d848SSeongJae Park 2642224d848SSeongJae Park /** 2654bc05954SSeongJae Park * damon_set_targets() - Set monitoring targets. 2664bc05954SSeongJae Park * @ctx: monitoring context 2674bc05954SSeongJae Park * @ids: array of target ids 2684bc05954SSeongJae Park * @nr_ids: number of entries in @ids 2694bc05954SSeongJae Park * 2704bc05954SSeongJae Park * This function should not be called while the kdamond is running. 2714bc05954SSeongJae Park * 2724bc05954SSeongJae Park * Return: 0 on success, negative error code otherwise. 2734bc05954SSeongJae Park */ 2744bc05954SSeongJae Park int damon_set_targets(struct damon_ctx *ctx, 2754bc05954SSeongJae Park unsigned long *ids, ssize_t nr_ids) 2764bc05954SSeongJae Park { 2774bc05954SSeongJae Park ssize_t i; 2784bc05954SSeongJae Park struct damon_target *t, *next; 2794bc05954SSeongJae Park 2804bc05954SSeongJae Park damon_destroy_targets(ctx); 2814bc05954SSeongJae Park 2824bc05954SSeongJae Park for (i = 0; i < nr_ids; i++) { 2834bc05954SSeongJae Park t = damon_new_target(ids[i]); 2844bc05954SSeongJae Park if (!t) { 2854bc05954SSeongJae Park pr_err("Failed to alloc damon_target\n"); 2864bc05954SSeongJae Park /* The caller should do cleanup of the ids itself */ 2874bc05954SSeongJae Park damon_for_each_target_safe(t, next, ctx) 2884bc05954SSeongJae Park damon_destroy_target(t); 2894bc05954SSeongJae Park return -ENOMEM; 2904bc05954SSeongJae Park } 2914bc05954SSeongJae Park damon_add_target(ctx, t); 2924bc05954SSeongJae Park } 2934bc05954SSeongJae Park 2944bc05954SSeongJae Park return 0; 2954bc05954SSeongJae Park } 2964bc05954SSeongJae Park 2974bc05954SSeongJae Park /** 2982224d848SSeongJae Park * damon_set_attrs() - Set attributes for the monitoring. 2992224d848SSeongJae Park * @ctx: monitoring context 3002224d848SSeongJae Park * @sample_int: time interval between samplings 3012224d848SSeongJae Park * @aggr_int: time interval between aggregations 3022224d848SSeongJae Park * @primitive_upd_int: time interval between monitoring primitive updates 303b9a6ac4eSSeongJae Park * @min_nr_reg: minimal number of regions 304b9a6ac4eSSeongJae Park * @max_nr_reg: maximum number of regions 3052224d848SSeongJae Park * 3062224d848SSeongJae Park * This function should not be called while the kdamond is running. 3072224d848SSeongJae Park * Every time interval is in micro-seconds. 3082224d848SSeongJae Park * 3092224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 3102224d848SSeongJae Park */ 3112224d848SSeongJae Park int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int, 312b9a6ac4eSSeongJae Park unsigned long aggr_int, unsigned long primitive_upd_int, 313b9a6ac4eSSeongJae Park unsigned long min_nr_reg, unsigned long max_nr_reg) 3142224d848SSeongJae Park { 315b9a6ac4eSSeongJae Park if (min_nr_reg < 3) { 316b9a6ac4eSSeongJae Park pr_err("min_nr_regions (%lu) must be at least 3\n", 317b9a6ac4eSSeongJae Park min_nr_reg); 318b9a6ac4eSSeongJae Park return -EINVAL; 319b9a6ac4eSSeongJae Park } 320b9a6ac4eSSeongJae Park if (min_nr_reg > max_nr_reg) { 321b9a6ac4eSSeongJae Park pr_err("invalid nr_regions. min (%lu) > max (%lu)\n", 322b9a6ac4eSSeongJae Park min_nr_reg, max_nr_reg); 323b9a6ac4eSSeongJae Park return -EINVAL; 324b9a6ac4eSSeongJae Park } 325b9a6ac4eSSeongJae Park 3262224d848SSeongJae Park ctx->sample_interval = sample_int; 3272224d848SSeongJae Park ctx->aggr_interval = aggr_int; 3282224d848SSeongJae Park ctx->primitive_update_interval = primitive_upd_int; 329b9a6ac4eSSeongJae Park ctx->min_nr_regions = min_nr_reg; 330b9a6ac4eSSeongJae Park ctx->max_nr_regions = max_nr_reg; 3312224d848SSeongJae Park 3322224d848SSeongJae Park return 0; 3332224d848SSeongJae Park } 3342224d848SSeongJae Park 3354bc05954SSeongJae Park /** 3361f366e42SSeongJae Park * damon_set_schemes() - Set data access monitoring based operation schemes. 3371f366e42SSeongJae Park * @ctx: monitoring context 3381f366e42SSeongJae Park * @schemes: array of the schemes 3391f366e42SSeongJae Park * @nr_schemes: number of entries in @schemes 3401f366e42SSeongJae Park * 3411f366e42SSeongJae Park * This function should not be called while the kdamond of the context is 3421f366e42SSeongJae Park * running. 3431f366e42SSeongJae Park * 3441f366e42SSeongJae Park * Return: 0 if success, or negative error code otherwise. 3451f366e42SSeongJae Park */ 3461f366e42SSeongJae Park int damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, 3471f366e42SSeongJae Park ssize_t nr_schemes) 3481f366e42SSeongJae Park { 3491f366e42SSeongJae Park struct damos *s, *next; 3501f366e42SSeongJae Park ssize_t i; 3511f366e42SSeongJae Park 3521f366e42SSeongJae Park damon_for_each_scheme_safe(s, next, ctx) 3531f366e42SSeongJae Park damon_destroy_scheme(s); 3541f366e42SSeongJae Park for (i = 0; i < nr_schemes; i++) 3551f366e42SSeongJae Park damon_add_scheme(ctx, schemes[i]); 3561f366e42SSeongJae Park return 0; 3571f366e42SSeongJae Park } 3581f366e42SSeongJae Park 3591f366e42SSeongJae Park /** 3604bc05954SSeongJae Park * damon_nr_running_ctxs() - Return number of currently running contexts. 3614bc05954SSeongJae Park */ 3624bc05954SSeongJae Park int damon_nr_running_ctxs(void) 3634bc05954SSeongJae Park { 3644bc05954SSeongJae Park int nr_ctxs; 3654bc05954SSeongJae Park 3664bc05954SSeongJae Park mutex_lock(&damon_lock); 3674bc05954SSeongJae Park nr_ctxs = nr_running_ctxs; 3684bc05954SSeongJae Park mutex_unlock(&damon_lock); 3694bc05954SSeongJae Park 3704bc05954SSeongJae Park return nr_ctxs; 3714bc05954SSeongJae Park } 3724bc05954SSeongJae Park 373b9a6ac4eSSeongJae Park /* Returns the size upper limit for each monitoring region */ 374b9a6ac4eSSeongJae Park static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) 375b9a6ac4eSSeongJae Park { 376b9a6ac4eSSeongJae Park struct damon_target *t; 377b9a6ac4eSSeongJae Park struct damon_region *r; 378b9a6ac4eSSeongJae Park unsigned long sz = 0; 379b9a6ac4eSSeongJae Park 380b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) { 381b9a6ac4eSSeongJae Park damon_for_each_region(r, t) 382b9a6ac4eSSeongJae Park sz += r->ar.end - r->ar.start; 383b9a6ac4eSSeongJae Park } 384b9a6ac4eSSeongJae Park 385b9a6ac4eSSeongJae Park if (ctx->min_nr_regions) 386b9a6ac4eSSeongJae Park sz /= ctx->min_nr_regions; 387b9a6ac4eSSeongJae Park if (sz < DAMON_MIN_REGION) 388b9a6ac4eSSeongJae Park sz = DAMON_MIN_REGION; 389b9a6ac4eSSeongJae Park 390b9a6ac4eSSeongJae Park return sz; 391b9a6ac4eSSeongJae Park } 392b9a6ac4eSSeongJae Park 3932224d848SSeongJae Park static int kdamond_fn(void *data); 3942224d848SSeongJae Park 3952224d848SSeongJae Park /* 3962224d848SSeongJae Park * __damon_start() - Starts monitoring with given context. 3972224d848SSeongJae Park * @ctx: monitoring context 3982224d848SSeongJae Park * 3992224d848SSeongJae Park * This function should be called while damon_lock is hold. 4002224d848SSeongJae Park * 4012224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4022224d848SSeongJae Park */ 4032224d848SSeongJae Park static int __damon_start(struct damon_ctx *ctx) 4042224d848SSeongJae Park { 4052224d848SSeongJae Park int err = -EBUSY; 4062224d848SSeongJae Park 4072224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 4082224d848SSeongJae Park if (!ctx->kdamond) { 4092224d848SSeongJae Park err = 0; 4102224d848SSeongJae Park ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", 4112224d848SSeongJae Park nr_running_ctxs); 4122224d848SSeongJae Park if (IS_ERR(ctx->kdamond)) { 4132224d848SSeongJae Park err = PTR_ERR(ctx->kdamond); 4147ec1992bSColin Ian King ctx->kdamond = NULL; 4152224d848SSeongJae Park } 4162224d848SSeongJae Park } 4172224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4182224d848SSeongJae Park 4192224d848SSeongJae Park return err; 4202224d848SSeongJae Park } 4212224d848SSeongJae Park 4222224d848SSeongJae Park /** 4232224d848SSeongJae Park * damon_start() - Starts the monitorings for a given group of contexts. 4242224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to start monitoring 4252224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4262224d848SSeongJae Park * 4272224d848SSeongJae Park * This function starts a group of monitoring threads for a group of monitoring 4282224d848SSeongJae Park * contexts. One thread per each context is created and run in parallel. The 4292224d848SSeongJae Park * caller should handle synchronization between the threads by itself. If a 4302224d848SSeongJae Park * group of threads that created by other 'damon_start()' call is currently 4312224d848SSeongJae Park * running, this function does nothing but returns -EBUSY. 4322224d848SSeongJae Park * 4332224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4342224d848SSeongJae Park */ 4352224d848SSeongJae Park int damon_start(struct damon_ctx **ctxs, int nr_ctxs) 4362224d848SSeongJae Park { 4372224d848SSeongJae Park int i; 4382224d848SSeongJae Park int err = 0; 4392224d848SSeongJae Park 4402224d848SSeongJae Park mutex_lock(&damon_lock); 4412224d848SSeongJae Park if (nr_running_ctxs) { 4422224d848SSeongJae Park mutex_unlock(&damon_lock); 4432224d848SSeongJae Park return -EBUSY; 4442224d848SSeongJae Park } 4452224d848SSeongJae Park 4462224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 4472224d848SSeongJae Park err = __damon_start(ctxs[i]); 4482224d848SSeongJae Park if (err) 4492224d848SSeongJae Park break; 4502224d848SSeongJae Park nr_running_ctxs++; 4512224d848SSeongJae Park } 4522224d848SSeongJae Park mutex_unlock(&damon_lock); 4532224d848SSeongJae Park 4542224d848SSeongJae Park return err; 4552224d848SSeongJae Park } 4562224d848SSeongJae Park 4572224d848SSeongJae Park /* 4582224d848SSeongJae Park * __damon_stop() - Stops monitoring of given context. 4592224d848SSeongJae Park * @ctx: monitoring context 4602224d848SSeongJae Park * 4612224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4622224d848SSeongJae Park */ 4632224d848SSeongJae Park static int __damon_stop(struct damon_ctx *ctx) 4642224d848SSeongJae Park { 465*0f91d133SChangbin Du struct task_struct *tsk; 466*0f91d133SChangbin Du 4672224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 468*0f91d133SChangbin Du tsk = ctx->kdamond; 469*0f91d133SChangbin Du if (tsk) { 470*0f91d133SChangbin Du get_task_struct(tsk); 4712224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 472*0f91d133SChangbin Du kthread_stop(tsk); 473*0f91d133SChangbin Du put_task_struct(tsk); 4742224d848SSeongJae Park return 0; 4752224d848SSeongJae Park } 4762224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4772224d848SSeongJae Park 4782224d848SSeongJae Park return -EPERM; 4792224d848SSeongJae Park } 4802224d848SSeongJae Park 4812224d848SSeongJae Park /** 4822224d848SSeongJae Park * damon_stop() - Stops the monitorings for a given group of contexts. 4832224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to stop monitoring 4842224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4852224d848SSeongJae Park * 4862224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4872224d848SSeongJae Park */ 4882224d848SSeongJae Park int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) 4892224d848SSeongJae Park { 4902224d848SSeongJae Park int i, err = 0; 4912224d848SSeongJae Park 4922224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 4932224d848SSeongJae Park /* nr_running_ctxs is decremented in kdamond_fn */ 4942224d848SSeongJae Park err = __damon_stop(ctxs[i]); 4952224d848SSeongJae Park if (err) 4962224d848SSeongJae Park return err; 4972224d848SSeongJae Park } 4982224d848SSeongJae Park 4992224d848SSeongJae Park return err; 5002224d848SSeongJae Park } 5012224d848SSeongJae Park 5022224d848SSeongJae Park /* 5032224d848SSeongJae Park * damon_check_reset_time_interval() - Check if a time interval is elapsed. 5042224d848SSeongJae Park * @baseline: the time to check whether the interval has elapsed since 5052224d848SSeongJae Park * @interval: the time interval (microseconds) 5062224d848SSeongJae Park * 5072224d848SSeongJae Park * See whether the given time interval has passed since the given baseline 5082224d848SSeongJae Park * time. If so, it also updates the baseline to current time for next check. 5092224d848SSeongJae Park * 5102224d848SSeongJae Park * Return: true if the time interval has passed, or false otherwise. 5112224d848SSeongJae Park */ 5122224d848SSeongJae Park static bool damon_check_reset_time_interval(struct timespec64 *baseline, 5132224d848SSeongJae Park unsigned long interval) 5142224d848SSeongJae Park { 5152224d848SSeongJae Park struct timespec64 now; 5162224d848SSeongJae Park 5172224d848SSeongJae Park ktime_get_coarse_ts64(&now); 5182224d848SSeongJae Park if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) < 5192224d848SSeongJae Park interval * 1000) 5202224d848SSeongJae Park return false; 5212224d848SSeongJae Park *baseline = now; 5222224d848SSeongJae Park return true; 5232224d848SSeongJae Park } 5242224d848SSeongJae Park 5252224d848SSeongJae Park /* 5262224d848SSeongJae Park * Check whether it is time to flush the aggregated information 5272224d848SSeongJae Park */ 5282224d848SSeongJae Park static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) 5292224d848SSeongJae Park { 5302224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_aggregation, 5312224d848SSeongJae Park ctx->aggr_interval); 5322224d848SSeongJae Park } 5332224d848SSeongJae Park 5342224d848SSeongJae Park /* 535f23b8eeeSSeongJae Park * Reset the aggregated monitoring results ('nr_accesses' of each region). 536f23b8eeeSSeongJae Park */ 537f23b8eeeSSeongJae Park static void kdamond_reset_aggregated(struct damon_ctx *c) 538f23b8eeeSSeongJae Park { 539f23b8eeeSSeongJae Park struct damon_target *t; 540f23b8eeeSSeongJae Park 541f23b8eeeSSeongJae Park damon_for_each_target(t, c) { 542f23b8eeeSSeongJae Park struct damon_region *r; 543f23b8eeeSSeongJae Park 5442fcb9362SSeongJae Park damon_for_each_region(r, t) { 5452fcb9362SSeongJae Park trace_damon_aggregated(t, r, damon_nr_regions(t)); 546fda504faSSeongJae Park r->last_nr_accesses = r->nr_accesses; 547f23b8eeeSSeongJae Park r->nr_accesses = 0; 548f23b8eeeSSeongJae Park } 549f23b8eeeSSeongJae Park } 5502fcb9362SSeongJae Park } 551f23b8eeeSSeongJae Park 5522b8a248dSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 5532b8a248dSSeongJae Park struct damon_target *t, struct damon_region *r, 5542b8a248dSSeongJae Park unsigned long sz_r); 5552b8a248dSSeongJae Park 55638683e00SSeongJae Park static bool __damos_valid_target(struct damon_region *r, struct damos *s) 55738683e00SSeongJae Park { 55838683e00SSeongJae Park unsigned long sz; 55938683e00SSeongJae Park 56038683e00SSeongJae Park sz = r->ar.end - r->ar.start; 56138683e00SSeongJae Park return s->min_sz_region <= sz && sz <= s->max_sz_region && 56238683e00SSeongJae Park s->min_nr_accesses <= r->nr_accesses && 56338683e00SSeongJae Park r->nr_accesses <= s->max_nr_accesses && 56438683e00SSeongJae Park s->min_age_region <= r->age && r->age <= s->max_age_region; 56538683e00SSeongJae Park } 56638683e00SSeongJae Park 56738683e00SSeongJae Park static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, 56838683e00SSeongJae Park struct damon_region *r, struct damos *s) 56938683e00SSeongJae Park { 57038683e00SSeongJae Park bool ret = __damos_valid_target(r, s); 57138683e00SSeongJae Park 57238683e00SSeongJae Park if (!ret || !s->quota.esz || !c->primitive.get_scheme_score) 57338683e00SSeongJae Park return ret; 57438683e00SSeongJae Park 57538683e00SSeongJae Park return c->primitive.get_scheme_score(c, t, r, s) >= s->quota.min_score; 57638683e00SSeongJae Park } 57738683e00SSeongJae Park 5781f366e42SSeongJae Park static void damon_do_apply_schemes(struct damon_ctx *c, 5791f366e42SSeongJae Park struct damon_target *t, 5801f366e42SSeongJae Park struct damon_region *r) 5811f366e42SSeongJae Park { 5821f366e42SSeongJae Park struct damos *s; 5831f366e42SSeongJae Park 5841f366e42SSeongJae Park damon_for_each_scheme(s, c) { 5852b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 5862b8a248dSSeongJae Park unsigned long sz = r->ar.end - r->ar.start; 5871cd24303SSeongJae Park struct timespec64 begin, end; 5882b8a248dSSeongJae Park 589ee801b7dSSeongJae Park if (!s->wmarks.activated) 590ee801b7dSSeongJae Park continue; 591ee801b7dSSeongJae Park 5922b8a248dSSeongJae Park /* Check the quota */ 5931cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 5942b8a248dSSeongJae Park continue; 5952b8a248dSSeongJae Park 59650585192SSeongJae Park /* Skip previously charged regions */ 59750585192SSeongJae Park if (quota->charge_target_from) { 59850585192SSeongJae Park if (t != quota->charge_target_from) 59950585192SSeongJae Park continue; 60050585192SSeongJae Park if (r == damon_last_region(t)) { 60150585192SSeongJae Park quota->charge_target_from = NULL; 60250585192SSeongJae Park quota->charge_addr_from = 0; 60350585192SSeongJae Park continue; 60450585192SSeongJae Park } 60550585192SSeongJae Park if (quota->charge_addr_from && 60650585192SSeongJae Park r->ar.end <= quota->charge_addr_from) 60750585192SSeongJae Park continue; 60850585192SSeongJae Park 60950585192SSeongJae Park if (quota->charge_addr_from && r->ar.start < 61050585192SSeongJae Park quota->charge_addr_from) { 61150585192SSeongJae Park sz = ALIGN_DOWN(quota->charge_addr_from - 61250585192SSeongJae Park r->ar.start, DAMON_MIN_REGION); 61350585192SSeongJae Park if (!sz) { 61450585192SSeongJae Park if (r->ar.end - r->ar.start <= 61550585192SSeongJae Park DAMON_MIN_REGION) 61650585192SSeongJae Park continue; 61750585192SSeongJae Park sz = DAMON_MIN_REGION; 61850585192SSeongJae Park } 61950585192SSeongJae Park damon_split_region_at(c, t, r, sz); 62050585192SSeongJae Park r = damon_next_region(r); 62150585192SSeongJae Park sz = r->ar.end - r->ar.start; 62250585192SSeongJae Park } 62350585192SSeongJae Park quota->charge_target_from = NULL; 62450585192SSeongJae Park quota->charge_addr_from = 0; 62550585192SSeongJae Park } 62650585192SSeongJae Park 62738683e00SSeongJae Park if (!damos_valid_target(c, t, r, s)) 6281f366e42SSeongJae Park continue; 6292b8a248dSSeongJae Park 6302b8a248dSSeongJae Park /* Apply the scheme */ 6312b8a248dSSeongJae Park if (c->primitive.apply_scheme) { 6321cd24303SSeongJae Park if (quota->esz && 6331cd24303SSeongJae Park quota->charged_sz + sz > quota->esz) { 6341cd24303SSeongJae Park sz = ALIGN_DOWN(quota->esz - quota->charged_sz, 6352b8a248dSSeongJae Park DAMON_MIN_REGION); 6362b8a248dSSeongJae Park if (!sz) 6372b8a248dSSeongJae Park goto update_stat; 6382b8a248dSSeongJae Park damon_split_region_at(c, t, r, sz); 6392b8a248dSSeongJae Park } 6401cd24303SSeongJae Park ktime_get_coarse_ts64(&begin); 6411f366e42SSeongJae Park c->primitive.apply_scheme(c, t, r, s); 6421cd24303SSeongJae Park ktime_get_coarse_ts64(&end); 6431cd24303SSeongJae Park quota->total_charged_ns += timespec64_to_ns(&end) - 6441cd24303SSeongJae Park timespec64_to_ns(&begin); 6452b8a248dSSeongJae Park quota->charged_sz += sz; 6461cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) { 64750585192SSeongJae Park quota->charge_target_from = t; 64850585192SSeongJae Park quota->charge_addr_from = r->ar.end + 1; 64950585192SSeongJae Park } 6502b8a248dSSeongJae Park } 6512f0b548cSSeongJae Park if (s->action != DAMOS_STAT) 6521f366e42SSeongJae Park r->age = 0; 6532b8a248dSSeongJae Park 6542b8a248dSSeongJae Park update_stat: 6552b8a248dSSeongJae Park s->stat_count++; 6562b8a248dSSeongJae Park s->stat_sz += sz; 6571f366e42SSeongJae Park } 6581f366e42SSeongJae Park } 6591f366e42SSeongJae Park 6601cd24303SSeongJae Park /* Shouldn't be called if quota->ms and quota->sz are zero */ 6611cd24303SSeongJae Park static void damos_set_effective_quota(struct damos_quota *quota) 6621cd24303SSeongJae Park { 6631cd24303SSeongJae Park unsigned long throughput; 6641cd24303SSeongJae Park unsigned long esz; 6651cd24303SSeongJae Park 6661cd24303SSeongJae Park if (!quota->ms) { 6671cd24303SSeongJae Park quota->esz = quota->sz; 6681cd24303SSeongJae Park return; 6691cd24303SSeongJae Park } 6701cd24303SSeongJae Park 6711cd24303SSeongJae Park if (quota->total_charged_ns) 6721cd24303SSeongJae Park throughput = quota->total_charged_sz * 1000000 / 6731cd24303SSeongJae Park quota->total_charged_ns; 6741cd24303SSeongJae Park else 6751cd24303SSeongJae Park throughput = PAGE_SIZE * 1024; 6761cd24303SSeongJae Park esz = throughput * quota->ms; 6771cd24303SSeongJae Park 6781cd24303SSeongJae Park if (quota->sz && quota->sz < esz) 6791cd24303SSeongJae Park esz = quota->sz; 6801cd24303SSeongJae Park quota->esz = esz; 6811cd24303SSeongJae Park } 6821cd24303SSeongJae Park 6831f366e42SSeongJae Park static void kdamond_apply_schemes(struct damon_ctx *c) 6841f366e42SSeongJae Park { 6851f366e42SSeongJae Park struct damon_target *t; 6862b8a248dSSeongJae Park struct damon_region *r, *next_r; 6872b8a248dSSeongJae Park struct damos *s; 6882b8a248dSSeongJae Park 6892b8a248dSSeongJae Park damon_for_each_scheme(s, c) { 6902b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 69138683e00SSeongJae Park unsigned long cumulated_sz; 69238683e00SSeongJae Park unsigned int score, max_score = 0; 6932b8a248dSSeongJae Park 694ee801b7dSSeongJae Park if (!s->wmarks.activated) 695ee801b7dSSeongJae Park continue; 696ee801b7dSSeongJae Park 6971cd24303SSeongJae Park if (!quota->ms && !quota->sz) 6982b8a248dSSeongJae Park continue; 6992b8a248dSSeongJae Park 7002b8a248dSSeongJae Park /* New charge window starts */ 7012b8a248dSSeongJae Park if (time_after_eq(jiffies, quota->charged_from + 7022b8a248dSSeongJae Park msecs_to_jiffies( 7032b8a248dSSeongJae Park quota->reset_interval))) { 7041cd24303SSeongJae Park quota->total_charged_sz += quota->charged_sz; 7052b8a248dSSeongJae Park quota->charged_from = jiffies; 7062b8a248dSSeongJae Park quota->charged_sz = 0; 7071cd24303SSeongJae Park damos_set_effective_quota(quota); 7082b8a248dSSeongJae Park } 70938683e00SSeongJae Park 71038683e00SSeongJae Park if (!c->primitive.get_scheme_score) 71138683e00SSeongJae Park continue; 71238683e00SSeongJae Park 71338683e00SSeongJae Park /* Fill up the score histogram */ 71438683e00SSeongJae Park memset(quota->histogram, 0, sizeof(quota->histogram)); 71538683e00SSeongJae Park damon_for_each_target(t, c) { 71638683e00SSeongJae Park damon_for_each_region(r, t) { 71738683e00SSeongJae Park if (!__damos_valid_target(r, s)) 71838683e00SSeongJae Park continue; 71938683e00SSeongJae Park score = c->primitive.get_scheme_score( 72038683e00SSeongJae Park c, t, r, s); 72138683e00SSeongJae Park quota->histogram[score] += 72238683e00SSeongJae Park r->ar.end - r->ar.start; 72338683e00SSeongJae Park if (score > max_score) 72438683e00SSeongJae Park max_score = score; 72538683e00SSeongJae Park } 72638683e00SSeongJae Park } 72738683e00SSeongJae Park 72838683e00SSeongJae Park /* Set the min score limit */ 72938683e00SSeongJae Park for (cumulated_sz = 0, score = max_score; ; score--) { 73038683e00SSeongJae Park cumulated_sz += quota->histogram[score]; 73138683e00SSeongJae Park if (cumulated_sz >= quota->esz || !score) 73238683e00SSeongJae Park break; 73338683e00SSeongJae Park } 73438683e00SSeongJae Park quota->min_score = score; 7352b8a248dSSeongJae Park } 7361f366e42SSeongJae Park 7371f366e42SSeongJae Park damon_for_each_target(t, c) { 7382b8a248dSSeongJae Park damon_for_each_region_safe(r, next_r, t) 7391f366e42SSeongJae Park damon_do_apply_schemes(c, t, r); 7401f366e42SSeongJae Park } 7411f366e42SSeongJae Park } 7421f366e42SSeongJae Park 743b9a6ac4eSSeongJae Park #define sz_damon_region(r) (r->ar.end - r->ar.start) 744b9a6ac4eSSeongJae Park 745b9a6ac4eSSeongJae Park /* 746b9a6ac4eSSeongJae Park * Merge two adjacent regions into one region 747b9a6ac4eSSeongJae Park */ 748b9a6ac4eSSeongJae Park static void damon_merge_two_regions(struct damon_target *t, 749b9a6ac4eSSeongJae Park struct damon_region *l, struct damon_region *r) 750b9a6ac4eSSeongJae Park { 751b9a6ac4eSSeongJae Park unsigned long sz_l = sz_damon_region(l), sz_r = sz_damon_region(r); 752b9a6ac4eSSeongJae Park 753b9a6ac4eSSeongJae Park l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / 754b9a6ac4eSSeongJae Park (sz_l + sz_r); 755fda504faSSeongJae Park l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); 756b9a6ac4eSSeongJae Park l->ar.end = r->ar.end; 757b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 758b9a6ac4eSSeongJae Park } 759b9a6ac4eSSeongJae Park 760b9a6ac4eSSeongJae Park #define diff_of(a, b) (a > b ? a - b : b - a) 761b9a6ac4eSSeongJae Park 762b9a6ac4eSSeongJae Park /* 763b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 764b9a6ac4eSSeongJae Park * 765b9a6ac4eSSeongJae Park * t target affected by this merge operation 766b9a6ac4eSSeongJae Park * thres '->nr_accesses' diff threshold for the merge 767b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 768b9a6ac4eSSeongJae Park */ 769b9a6ac4eSSeongJae Park static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, 770b9a6ac4eSSeongJae Park unsigned long sz_limit) 771b9a6ac4eSSeongJae Park { 772b9a6ac4eSSeongJae Park struct damon_region *r, *prev = NULL, *next; 773b9a6ac4eSSeongJae Park 774b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 775fda504faSSeongJae Park if (diff_of(r->nr_accesses, r->last_nr_accesses) > thres) 776fda504faSSeongJae Park r->age = 0; 777fda504faSSeongJae Park else 778fda504faSSeongJae Park r->age++; 779fda504faSSeongJae Park 780b9a6ac4eSSeongJae Park if (prev && prev->ar.end == r->ar.start && 781b9a6ac4eSSeongJae Park diff_of(prev->nr_accesses, r->nr_accesses) <= thres && 782b9a6ac4eSSeongJae Park sz_damon_region(prev) + sz_damon_region(r) <= sz_limit) 783b9a6ac4eSSeongJae Park damon_merge_two_regions(t, prev, r); 784b9a6ac4eSSeongJae Park else 785b9a6ac4eSSeongJae Park prev = r; 786b9a6ac4eSSeongJae Park } 787b9a6ac4eSSeongJae Park } 788b9a6ac4eSSeongJae Park 789b9a6ac4eSSeongJae Park /* 790b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 791b9a6ac4eSSeongJae Park * 792b9a6ac4eSSeongJae Park * threshold '->nr_accesses' diff threshold for the merge 793b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 794b9a6ac4eSSeongJae Park * 795b9a6ac4eSSeongJae Park * This function merges monitoring target regions which are adjacent and their 796b9a6ac4eSSeongJae Park * access frequencies are similar. This is for minimizing the monitoring 797b9a6ac4eSSeongJae Park * overhead under the dynamically changeable access pattern. If a merge was 798b9a6ac4eSSeongJae Park * unnecessarily made, later 'kdamond_split_regions()' will revert it. 799b9a6ac4eSSeongJae Park */ 800b9a6ac4eSSeongJae Park static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, 801b9a6ac4eSSeongJae Park unsigned long sz_limit) 802b9a6ac4eSSeongJae Park { 803b9a6ac4eSSeongJae Park struct damon_target *t; 804b9a6ac4eSSeongJae Park 805b9a6ac4eSSeongJae Park damon_for_each_target(t, c) 806b9a6ac4eSSeongJae Park damon_merge_regions_of(t, threshold, sz_limit); 807b9a6ac4eSSeongJae Park } 808b9a6ac4eSSeongJae Park 809b9a6ac4eSSeongJae Park /* 810b9a6ac4eSSeongJae Park * Split a region in two 811b9a6ac4eSSeongJae Park * 812b9a6ac4eSSeongJae Park * r the region to be split 813b9a6ac4eSSeongJae Park * sz_r size of the first sub-region that will be made 814b9a6ac4eSSeongJae Park */ 815b9a6ac4eSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 816b9a6ac4eSSeongJae Park struct damon_target *t, struct damon_region *r, 817b9a6ac4eSSeongJae Park unsigned long sz_r) 818b9a6ac4eSSeongJae Park { 819b9a6ac4eSSeongJae Park struct damon_region *new; 820b9a6ac4eSSeongJae Park 821b9a6ac4eSSeongJae Park new = damon_new_region(r->ar.start + sz_r, r->ar.end); 822b9a6ac4eSSeongJae Park if (!new) 823b9a6ac4eSSeongJae Park return; 824b9a6ac4eSSeongJae Park 825b9a6ac4eSSeongJae Park r->ar.end = new->ar.start; 826b9a6ac4eSSeongJae Park 827fda504faSSeongJae Park new->age = r->age; 828fda504faSSeongJae Park new->last_nr_accesses = r->last_nr_accesses; 829fda504faSSeongJae Park 830b9a6ac4eSSeongJae Park damon_insert_region(new, r, damon_next_region(r), t); 831b9a6ac4eSSeongJae Park } 832b9a6ac4eSSeongJae Park 833b9a6ac4eSSeongJae Park /* Split every region in the given target into 'nr_subs' regions */ 834b9a6ac4eSSeongJae Park static void damon_split_regions_of(struct damon_ctx *ctx, 835b9a6ac4eSSeongJae Park struct damon_target *t, int nr_subs) 836b9a6ac4eSSeongJae Park { 837b9a6ac4eSSeongJae Park struct damon_region *r, *next; 838b9a6ac4eSSeongJae Park unsigned long sz_region, sz_sub = 0; 839b9a6ac4eSSeongJae Park int i; 840b9a6ac4eSSeongJae Park 841b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 842b9a6ac4eSSeongJae Park sz_region = r->ar.end - r->ar.start; 843b9a6ac4eSSeongJae Park 844b9a6ac4eSSeongJae Park for (i = 0; i < nr_subs - 1 && 845b9a6ac4eSSeongJae Park sz_region > 2 * DAMON_MIN_REGION; i++) { 846b9a6ac4eSSeongJae Park /* 847b9a6ac4eSSeongJae Park * Randomly select size of left sub-region to be at 848b9a6ac4eSSeongJae Park * least 10 percent and at most 90% of original region 849b9a6ac4eSSeongJae Park */ 850b9a6ac4eSSeongJae Park sz_sub = ALIGN_DOWN(damon_rand(1, 10) * 851b9a6ac4eSSeongJae Park sz_region / 10, DAMON_MIN_REGION); 852b9a6ac4eSSeongJae Park /* Do not allow blank region */ 853b9a6ac4eSSeongJae Park if (sz_sub == 0 || sz_sub >= sz_region) 854b9a6ac4eSSeongJae Park continue; 855b9a6ac4eSSeongJae Park 856b9a6ac4eSSeongJae Park damon_split_region_at(ctx, t, r, sz_sub); 857b9a6ac4eSSeongJae Park sz_region = sz_sub; 858b9a6ac4eSSeongJae Park } 859b9a6ac4eSSeongJae Park } 860b9a6ac4eSSeongJae Park } 861b9a6ac4eSSeongJae Park 862b9a6ac4eSSeongJae Park /* 863b9a6ac4eSSeongJae Park * Split every target region into randomly-sized small regions 864b9a6ac4eSSeongJae Park * 865b9a6ac4eSSeongJae Park * This function splits every target region into random-sized small regions if 866b9a6ac4eSSeongJae Park * current total number of the regions is equal or smaller than half of the 867b9a6ac4eSSeongJae Park * user-specified maximum number of regions. This is for maximizing the 868b9a6ac4eSSeongJae Park * monitoring accuracy under the dynamically changeable access patterns. If a 869b9a6ac4eSSeongJae Park * split was unnecessarily made, later 'kdamond_merge_regions()' will revert 870b9a6ac4eSSeongJae Park * it. 871b9a6ac4eSSeongJae Park */ 872b9a6ac4eSSeongJae Park static void kdamond_split_regions(struct damon_ctx *ctx) 873b9a6ac4eSSeongJae Park { 874b9a6ac4eSSeongJae Park struct damon_target *t; 875b9a6ac4eSSeongJae Park unsigned int nr_regions = 0; 876b9a6ac4eSSeongJae Park static unsigned int last_nr_regions; 877b9a6ac4eSSeongJae Park int nr_subregions = 2; 878b9a6ac4eSSeongJae Park 879b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 880b9a6ac4eSSeongJae Park nr_regions += damon_nr_regions(t); 881b9a6ac4eSSeongJae Park 882b9a6ac4eSSeongJae Park if (nr_regions > ctx->max_nr_regions / 2) 883b9a6ac4eSSeongJae Park return; 884b9a6ac4eSSeongJae Park 885b9a6ac4eSSeongJae Park /* Maybe the middle of the region has different access frequency */ 886b9a6ac4eSSeongJae Park if (last_nr_regions == nr_regions && 887b9a6ac4eSSeongJae Park nr_regions < ctx->max_nr_regions / 3) 888b9a6ac4eSSeongJae Park nr_subregions = 3; 889b9a6ac4eSSeongJae Park 890b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 891b9a6ac4eSSeongJae Park damon_split_regions_of(ctx, t, nr_subregions); 892b9a6ac4eSSeongJae Park 893b9a6ac4eSSeongJae Park last_nr_regions = nr_regions; 894b9a6ac4eSSeongJae Park } 895b9a6ac4eSSeongJae Park 896f23b8eeeSSeongJae Park /* 8972224d848SSeongJae Park * Check whether it is time to check and apply the target monitoring regions 8982224d848SSeongJae Park * 8992224d848SSeongJae Park * Returns true if it is. 9002224d848SSeongJae Park */ 9012224d848SSeongJae Park static bool kdamond_need_update_primitive(struct damon_ctx *ctx) 9022224d848SSeongJae Park { 9032224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_primitive_update, 9042224d848SSeongJae Park ctx->primitive_update_interval); 9052224d848SSeongJae Park } 9062224d848SSeongJae Park 9072224d848SSeongJae Park /* 9082224d848SSeongJae Park * Check whether current monitoring should be stopped 9092224d848SSeongJae Park * 9102224d848SSeongJae Park * The monitoring is stopped when either the user requested to stop, or all 9112224d848SSeongJae Park * monitoring targets are invalid. 9122224d848SSeongJae Park * 9132224d848SSeongJae Park * Returns true if need to stop current monitoring. 9142224d848SSeongJae Park */ 9152224d848SSeongJae Park static bool kdamond_need_stop(struct damon_ctx *ctx) 9162224d848SSeongJae Park { 917f23b8eeeSSeongJae Park struct damon_target *t; 9182224d848SSeongJae Park 919*0f91d133SChangbin Du if (kthread_should_stop()) 9202224d848SSeongJae Park return true; 9212224d848SSeongJae Park 9222224d848SSeongJae Park if (!ctx->primitive.target_valid) 9232224d848SSeongJae Park return false; 9242224d848SSeongJae Park 925f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 926f23b8eeeSSeongJae Park if (ctx->primitive.target_valid(t)) 927f23b8eeeSSeongJae Park return false; 928f23b8eeeSSeongJae Park } 929f23b8eeeSSeongJae Park 930f23b8eeeSSeongJae Park return true; 9312224d848SSeongJae Park } 9322224d848SSeongJae Park 933ee801b7dSSeongJae Park static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) 934ee801b7dSSeongJae Park { 935ee801b7dSSeongJae Park struct sysinfo i; 936ee801b7dSSeongJae Park 937ee801b7dSSeongJae Park switch (metric) { 938ee801b7dSSeongJae Park case DAMOS_WMARK_FREE_MEM_RATE: 939ee801b7dSSeongJae Park si_meminfo(&i); 940ee801b7dSSeongJae Park return i.freeram * 1000 / i.totalram; 941ee801b7dSSeongJae Park default: 942ee801b7dSSeongJae Park break; 943ee801b7dSSeongJae Park } 944ee801b7dSSeongJae Park return -EINVAL; 945ee801b7dSSeongJae Park } 946ee801b7dSSeongJae Park 947ee801b7dSSeongJae Park /* 948ee801b7dSSeongJae Park * Returns zero if the scheme is active. Else, returns time to wait for next 949ee801b7dSSeongJae Park * watermark check in micro-seconds. 950ee801b7dSSeongJae Park */ 951ee801b7dSSeongJae Park static unsigned long damos_wmark_wait_us(struct damos *scheme) 952ee801b7dSSeongJae Park { 953ee801b7dSSeongJae Park unsigned long metric; 954ee801b7dSSeongJae Park 955ee801b7dSSeongJae Park if (scheme->wmarks.metric == DAMOS_WMARK_NONE) 956ee801b7dSSeongJae Park return 0; 957ee801b7dSSeongJae Park 958ee801b7dSSeongJae Park metric = damos_wmark_metric_value(scheme->wmarks.metric); 959ee801b7dSSeongJae Park /* higher than high watermark or lower than low watermark */ 960ee801b7dSSeongJae Park if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { 961ee801b7dSSeongJae Park if (scheme->wmarks.activated) 962ee801b7dSSeongJae Park pr_debug("inactivate a scheme (%d) for %s wmark\n", 963ee801b7dSSeongJae Park scheme->action, 964ee801b7dSSeongJae Park metric > scheme->wmarks.high ? 965ee801b7dSSeongJae Park "high" : "low"); 966ee801b7dSSeongJae Park scheme->wmarks.activated = false; 967ee801b7dSSeongJae Park return scheme->wmarks.interval; 968ee801b7dSSeongJae Park } 969ee801b7dSSeongJae Park 970ee801b7dSSeongJae Park /* inactive and higher than middle watermark */ 971ee801b7dSSeongJae Park if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && 972ee801b7dSSeongJae Park !scheme->wmarks.activated) 973ee801b7dSSeongJae Park return scheme->wmarks.interval; 974ee801b7dSSeongJae Park 975ee801b7dSSeongJae Park if (!scheme->wmarks.activated) 976ee801b7dSSeongJae Park pr_debug("activate a scheme (%d)\n", scheme->action); 977ee801b7dSSeongJae Park scheme->wmarks.activated = true; 978ee801b7dSSeongJae Park return 0; 979ee801b7dSSeongJae Park } 980ee801b7dSSeongJae Park 981ee801b7dSSeongJae Park static void kdamond_usleep(unsigned long usecs) 982ee801b7dSSeongJae Park { 983ee801b7dSSeongJae Park if (usecs > 100 * 1000) 984ee801b7dSSeongJae Park schedule_timeout_interruptible(usecs_to_jiffies(usecs)); 985ee801b7dSSeongJae Park else 986ee801b7dSSeongJae Park usleep_range(usecs, usecs + 1); 987ee801b7dSSeongJae Park } 988ee801b7dSSeongJae Park 989ee801b7dSSeongJae Park /* Returns negative error code if it's not activated but should return */ 990ee801b7dSSeongJae Park static int kdamond_wait_activation(struct damon_ctx *ctx) 991ee801b7dSSeongJae Park { 992ee801b7dSSeongJae Park struct damos *s; 993ee801b7dSSeongJae Park unsigned long wait_time; 994ee801b7dSSeongJae Park unsigned long min_wait_time = 0; 995ee801b7dSSeongJae Park 996ee801b7dSSeongJae Park while (!kdamond_need_stop(ctx)) { 997ee801b7dSSeongJae Park damon_for_each_scheme(s, ctx) { 998ee801b7dSSeongJae Park wait_time = damos_wmark_wait_us(s); 999ee801b7dSSeongJae Park if (!min_wait_time || wait_time < min_wait_time) 1000ee801b7dSSeongJae Park min_wait_time = wait_time; 1001ee801b7dSSeongJae Park } 1002ee801b7dSSeongJae Park if (!min_wait_time) 1003ee801b7dSSeongJae Park return 0; 1004ee801b7dSSeongJae Park 1005ee801b7dSSeongJae Park kdamond_usleep(min_wait_time); 1006ee801b7dSSeongJae Park } 1007ee801b7dSSeongJae Park return -EBUSY; 1008ee801b7dSSeongJae Park } 1009ee801b7dSSeongJae Park 10102224d848SSeongJae Park /* 10112224d848SSeongJae Park * The monitoring daemon that runs as a kernel thread 10122224d848SSeongJae Park */ 10132224d848SSeongJae Park static int kdamond_fn(void *data) 10142224d848SSeongJae Park { 10152224d848SSeongJae Park struct damon_ctx *ctx = (struct damon_ctx *)data; 1016f23b8eeeSSeongJae Park struct damon_target *t; 1017f23b8eeeSSeongJae Park struct damon_region *r, *next; 1018b9a6ac4eSSeongJae Park unsigned int max_nr_accesses = 0; 1019b9a6ac4eSSeongJae Park unsigned long sz_limit = 0; 1020*0f91d133SChangbin Du bool done = false; 10212224d848SSeongJae Park 102242e4cef5SChangbin Du pr_debug("kdamond (%d) starts\n", current->pid); 10232224d848SSeongJae Park 10242224d848SSeongJae Park if (ctx->primitive.init) 10252224d848SSeongJae Park ctx->primitive.init(ctx); 10262224d848SSeongJae Park if (ctx->callback.before_start && ctx->callback.before_start(ctx)) 1027*0f91d133SChangbin Du done = true; 10282224d848SSeongJae Park 1029b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 1030b9a6ac4eSSeongJae Park 1031*0f91d133SChangbin Du while (!kdamond_need_stop(ctx) && !done) { 1032ee801b7dSSeongJae Park if (kdamond_wait_activation(ctx)) 1033ee801b7dSSeongJae Park continue; 1034ee801b7dSSeongJae Park 10352224d848SSeongJae Park if (ctx->primitive.prepare_access_checks) 10362224d848SSeongJae Park ctx->primitive.prepare_access_checks(ctx); 10372224d848SSeongJae Park if (ctx->callback.after_sampling && 10382224d848SSeongJae Park ctx->callback.after_sampling(ctx)) 1039*0f91d133SChangbin Du done = true; 10402224d848SSeongJae Park 10412224d848SSeongJae Park usleep_range(ctx->sample_interval, ctx->sample_interval + 1); 10422224d848SSeongJae Park 10432224d848SSeongJae Park if (ctx->primitive.check_accesses) 1044b9a6ac4eSSeongJae Park max_nr_accesses = ctx->primitive.check_accesses(ctx); 10452224d848SSeongJae Park 10462224d848SSeongJae Park if (kdamond_aggregate_interval_passed(ctx)) { 1047b9a6ac4eSSeongJae Park kdamond_merge_regions(ctx, 1048b9a6ac4eSSeongJae Park max_nr_accesses / 10, 1049b9a6ac4eSSeongJae Park sz_limit); 10502224d848SSeongJae Park if (ctx->callback.after_aggregation && 10512224d848SSeongJae Park ctx->callback.after_aggregation(ctx)) 1052*0f91d133SChangbin Du done = true; 10531f366e42SSeongJae Park kdamond_apply_schemes(ctx); 1054f23b8eeeSSeongJae Park kdamond_reset_aggregated(ctx); 1055b9a6ac4eSSeongJae Park kdamond_split_regions(ctx); 10562224d848SSeongJae Park if (ctx->primitive.reset_aggregated) 10572224d848SSeongJae Park ctx->primitive.reset_aggregated(ctx); 10582224d848SSeongJae Park } 10592224d848SSeongJae Park 10602224d848SSeongJae Park if (kdamond_need_update_primitive(ctx)) { 10612224d848SSeongJae Park if (ctx->primitive.update) 10622224d848SSeongJae Park ctx->primitive.update(ctx); 1063b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 10642224d848SSeongJae Park } 10652224d848SSeongJae Park } 1066f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 1067f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 1068b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 1069f23b8eeeSSeongJae Park } 10702224d848SSeongJae Park 1071*0f91d133SChangbin Du if (ctx->callback.before_terminate) 1072*0f91d133SChangbin Du ctx->callback.before_terminate(ctx); 10732224d848SSeongJae Park if (ctx->primitive.cleanup) 10742224d848SSeongJae Park ctx->primitive.cleanup(ctx); 10752224d848SSeongJae Park 107642e4cef5SChangbin Du pr_debug("kdamond (%d) finishes\n", current->pid); 10772224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 10782224d848SSeongJae Park ctx->kdamond = NULL; 10792224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 10802224d848SSeongJae Park 10812224d848SSeongJae Park mutex_lock(&damon_lock); 10822224d848SSeongJae Park nr_running_ctxs--; 10832224d848SSeongJae Park mutex_unlock(&damon_lock); 10842224d848SSeongJae Park 10855f7fe2b9SChangbin Du return 0; 10862224d848SSeongJae Park } 108717ccae8bSSeongJae Park 108817ccae8bSSeongJae Park #include "core-test.h" 1089