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; 272224d848SSeongJae Park 28f23b8eeeSSeongJae Park /* 29f23b8eeeSSeongJae Park * Construct a damon_region struct 30f23b8eeeSSeongJae Park * 31f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 32f23b8eeeSSeongJae Park */ 33f23b8eeeSSeongJae Park struct damon_region *damon_new_region(unsigned long start, unsigned long end) 34f23b8eeeSSeongJae Park { 35f23b8eeeSSeongJae Park struct damon_region *region; 36f23b8eeeSSeongJae Park 37f23b8eeeSSeongJae Park region = kmalloc(sizeof(*region), GFP_KERNEL); 38f23b8eeeSSeongJae Park if (!region) 39f23b8eeeSSeongJae Park return NULL; 40f23b8eeeSSeongJae Park 41f23b8eeeSSeongJae Park region->ar.start = start; 42f23b8eeeSSeongJae Park region->ar.end = end; 43f23b8eeeSSeongJae Park region->nr_accesses = 0; 44f23b8eeeSSeongJae Park INIT_LIST_HEAD(®ion->list); 45f23b8eeeSSeongJae Park 46fda504faSSeongJae Park region->age = 0; 47fda504faSSeongJae Park region->last_nr_accesses = 0; 48fda504faSSeongJae Park 49f23b8eeeSSeongJae Park return region; 50f23b8eeeSSeongJae Park } 51f23b8eeeSSeongJae Park 52f23b8eeeSSeongJae Park /* 53f23b8eeeSSeongJae Park * Add a region between two other regions 54f23b8eeeSSeongJae Park */ 55f23b8eeeSSeongJae Park inline void damon_insert_region(struct damon_region *r, 56b9a6ac4eSSeongJae Park struct damon_region *prev, struct damon_region *next, 57b9a6ac4eSSeongJae Park struct damon_target *t) 58f23b8eeeSSeongJae Park { 59f23b8eeeSSeongJae Park __list_add(&r->list, &prev->list, &next->list); 60b9a6ac4eSSeongJae Park t->nr_regions++; 61f23b8eeeSSeongJae Park } 62f23b8eeeSSeongJae Park 63f23b8eeeSSeongJae Park void damon_add_region(struct damon_region *r, struct damon_target *t) 64f23b8eeeSSeongJae Park { 65f23b8eeeSSeongJae Park list_add_tail(&r->list, &t->regions_list); 66b9a6ac4eSSeongJae Park t->nr_regions++; 67f23b8eeeSSeongJae Park } 68f23b8eeeSSeongJae Park 69b9a6ac4eSSeongJae Park static void damon_del_region(struct damon_region *r, struct damon_target *t) 70f23b8eeeSSeongJae Park { 71f23b8eeeSSeongJae Park list_del(&r->list); 72b9a6ac4eSSeongJae Park t->nr_regions--; 73f23b8eeeSSeongJae Park } 74f23b8eeeSSeongJae Park 75f23b8eeeSSeongJae Park static void damon_free_region(struct damon_region *r) 76f23b8eeeSSeongJae Park { 77f23b8eeeSSeongJae Park kfree(r); 78f23b8eeeSSeongJae Park } 79f23b8eeeSSeongJae Park 80b9a6ac4eSSeongJae Park void damon_destroy_region(struct damon_region *r, struct damon_target *t) 81f23b8eeeSSeongJae Park { 82b9a6ac4eSSeongJae Park damon_del_region(r, t); 83f23b8eeeSSeongJae Park damon_free_region(r); 84f23b8eeeSSeongJae Park } 85f23b8eeeSSeongJae Park 861f366e42SSeongJae Park struct damos *damon_new_scheme( 871f366e42SSeongJae Park unsigned long min_sz_region, unsigned long max_sz_region, 881f366e42SSeongJae Park unsigned int min_nr_accesses, unsigned int max_nr_accesses, 891f366e42SSeongJae Park unsigned int min_age_region, unsigned int max_age_region, 90ee801b7dSSeongJae Park enum damos_action action, struct damos_quota *quota, 91ee801b7dSSeongJae Park struct damos_watermarks *wmarks) 921f366e42SSeongJae Park { 931f366e42SSeongJae Park struct damos *scheme; 941f366e42SSeongJae Park 951f366e42SSeongJae Park scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); 961f366e42SSeongJae Park if (!scheme) 971f366e42SSeongJae Park return NULL; 981f366e42SSeongJae Park scheme->min_sz_region = min_sz_region; 991f366e42SSeongJae Park scheme->max_sz_region = max_sz_region; 1001f366e42SSeongJae Park scheme->min_nr_accesses = min_nr_accesses; 1011f366e42SSeongJae Park scheme->max_nr_accesses = max_nr_accesses; 1021f366e42SSeongJae Park scheme->min_age_region = min_age_region; 1031f366e42SSeongJae Park scheme->max_age_region = max_age_region; 1041f366e42SSeongJae Park scheme->action = action; 105*0e92c2eeSSeongJae Park scheme->stat = (struct damos_stat){}; 1061f366e42SSeongJae Park INIT_LIST_HEAD(&scheme->list); 1071f366e42SSeongJae Park 1081cd24303SSeongJae Park scheme->quota.ms = quota->ms; 1092b8a248dSSeongJae Park scheme->quota.sz = quota->sz; 1102b8a248dSSeongJae Park scheme->quota.reset_interval = quota->reset_interval; 11138683e00SSeongJae Park scheme->quota.weight_sz = quota->weight_sz; 11238683e00SSeongJae Park scheme->quota.weight_nr_accesses = quota->weight_nr_accesses; 11338683e00SSeongJae Park scheme->quota.weight_age = quota->weight_age; 1141cd24303SSeongJae Park scheme->quota.total_charged_sz = 0; 1151cd24303SSeongJae Park scheme->quota.total_charged_ns = 0; 1161cd24303SSeongJae Park scheme->quota.esz = 0; 1172b8a248dSSeongJae Park scheme->quota.charged_sz = 0; 1182b8a248dSSeongJae Park scheme->quota.charged_from = 0; 11950585192SSeongJae Park scheme->quota.charge_target_from = NULL; 12050585192SSeongJae Park scheme->quota.charge_addr_from = 0; 1212b8a248dSSeongJae Park 122ee801b7dSSeongJae Park scheme->wmarks.metric = wmarks->metric; 123ee801b7dSSeongJae Park scheme->wmarks.interval = wmarks->interval; 124ee801b7dSSeongJae Park scheme->wmarks.high = wmarks->high; 125ee801b7dSSeongJae Park scheme->wmarks.mid = wmarks->mid; 126ee801b7dSSeongJae Park scheme->wmarks.low = wmarks->low; 127ee801b7dSSeongJae Park scheme->wmarks.activated = true; 128ee801b7dSSeongJae Park 1291f366e42SSeongJae Park return scheme; 1301f366e42SSeongJae Park } 1311f366e42SSeongJae Park 1321f366e42SSeongJae Park void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) 1331f366e42SSeongJae Park { 1341f366e42SSeongJae Park list_add_tail(&s->list, &ctx->schemes); 1351f366e42SSeongJae Park } 1361f366e42SSeongJae Park 1371f366e42SSeongJae Park static void damon_del_scheme(struct damos *s) 1381f366e42SSeongJae Park { 1391f366e42SSeongJae Park list_del(&s->list); 1401f366e42SSeongJae Park } 1411f366e42SSeongJae Park 1421f366e42SSeongJae Park static void damon_free_scheme(struct damos *s) 1431f366e42SSeongJae Park { 1441f366e42SSeongJae Park kfree(s); 1451f366e42SSeongJae Park } 1461f366e42SSeongJae Park 1471f366e42SSeongJae Park void damon_destroy_scheme(struct damos *s) 1481f366e42SSeongJae Park { 1491f366e42SSeongJae Park damon_del_scheme(s); 1501f366e42SSeongJae Park damon_free_scheme(s); 1511f366e42SSeongJae Park } 1521f366e42SSeongJae Park 153f23b8eeeSSeongJae Park /* 154f23b8eeeSSeongJae Park * Construct a damon_target struct 155f23b8eeeSSeongJae Park * 156f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 157f23b8eeeSSeongJae Park */ 158f23b8eeeSSeongJae Park struct damon_target *damon_new_target(unsigned long id) 159f23b8eeeSSeongJae Park { 160f23b8eeeSSeongJae Park struct damon_target *t; 161f23b8eeeSSeongJae Park 162f23b8eeeSSeongJae Park t = kmalloc(sizeof(*t), GFP_KERNEL); 163f23b8eeeSSeongJae Park if (!t) 164f23b8eeeSSeongJae Park return NULL; 165f23b8eeeSSeongJae Park 166f23b8eeeSSeongJae Park t->id = id; 167b9a6ac4eSSeongJae Park t->nr_regions = 0; 168f23b8eeeSSeongJae Park INIT_LIST_HEAD(&t->regions_list); 169f23b8eeeSSeongJae Park 170f23b8eeeSSeongJae Park return t; 171f23b8eeeSSeongJae Park } 172f23b8eeeSSeongJae Park 173f23b8eeeSSeongJae Park void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) 174f23b8eeeSSeongJae Park { 175b9a6ac4eSSeongJae Park list_add_tail(&t->list, &ctx->adaptive_targets); 176f23b8eeeSSeongJae Park } 177f23b8eeeSSeongJae Park 178b5ca3e83SXin Hao bool damon_targets_empty(struct damon_ctx *ctx) 179b5ca3e83SXin Hao { 180b5ca3e83SXin Hao return list_empty(&ctx->adaptive_targets); 181b5ca3e83SXin Hao } 182b5ca3e83SXin Hao 183f23b8eeeSSeongJae Park static void damon_del_target(struct damon_target *t) 184f23b8eeeSSeongJae Park { 185f23b8eeeSSeongJae Park list_del(&t->list); 186f23b8eeeSSeongJae Park } 187f23b8eeeSSeongJae Park 188f23b8eeeSSeongJae Park void damon_free_target(struct damon_target *t) 189f23b8eeeSSeongJae Park { 190f23b8eeeSSeongJae Park struct damon_region *r, *next; 191f23b8eeeSSeongJae Park 192f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 193f23b8eeeSSeongJae Park damon_free_region(r); 194f23b8eeeSSeongJae Park kfree(t); 195f23b8eeeSSeongJae Park } 196f23b8eeeSSeongJae Park 197f23b8eeeSSeongJae Park void damon_destroy_target(struct damon_target *t) 198f23b8eeeSSeongJae Park { 199f23b8eeeSSeongJae Park damon_del_target(t); 200f23b8eeeSSeongJae Park damon_free_target(t); 201f23b8eeeSSeongJae Park } 202f23b8eeeSSeongJae Park 203b9a6ac4eSSeongJae Park unsigned int damon_nr_regions(struct damon_target *t) 204b9a6ac4eSSeongJae Park { 205b9a6ac4eSSeongJae Park return t->nr_regions; 206b9a6ac4eSSeongJae Park } 207b9a6ac4eSSeongJae Park 2082224d848SSeongJae Park struct damon_ctx *damon_new_ctx(void) 2092224d848SSeongJae Park { 2102224d848SSeongJae Park struct damon_ctx *ctx; 2112224d848SSeongJae Park 2122224d848SSeongJae Park ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 2132224d848SSeongJae Park if (!ctx) 2142224d848SSeongJae Park return NULL; 2152224d848SSeongJae Park 2162224d848SSeongJae Park ctx->sample_interval = 5 * 1000; 2172224d848SSeongJae Park ctx->aggr_interval = 100 * 1000; 2182224d848SSeongJae Park ctx->primitive_update_interval = 60 * 1000 * 1000; 2192224d848SSeongJae Park 2202224d848SSeongJae Park ktime_get_coarse_ts64(&ctx->last_aggregation); 2212224d848SSeongJae Park ctx->last_primitive_update = ctx->last_aggregation; 2222224d848SSeongJae Park 2232224d848SSeongJae Park mutex_init(&ctx->kdamond_lock); 2242224d848SSeongJae Park 225b9a6ac4eSSeongJae Park ctx->min_nr_regions = 10; 226b9a6ac4eSSeongJae Park ctx->max_nr_regions = 1000; 227b9a6ac4eSSeongJae Park 228b9a6ac4eSSeongJae Park INIT_LIST_HEAD(&ctx->adaptive_targets); 2291f366e42SSeongJae Park INIT_LIST_HEAD(&ctx->schemes); 2302224d848SSeongJae Park 2312224d848SSeongJae Park return ctx; 2322224d848SSeongJae Park } 2332224d848SSeongJae Park 234f23b8eeeSSeongJae Park static void damon_destroy_targets(struct damon_ctx *ctx) 235f23b8eeeSSeongJae Park { 236f23b8eeeSSeongJae Park struct damon_target *t, *next_t; 237f23b8eeeSSeongJae Park 238f23b8eeeSSeongJae Park if (ctx->primitive.cleanup) { 239f23b8eeeSSeongJae Park ctx->primitive.cleanup(ctx); 240f23b8eeeSSeongJae Park return; 241f23b8eeeSSeongJae Park } 242f23b8eeeSSeongJae Park 243f23b8eeeSSeongJae Park damon_for_each_target_safe(t, next_t, ctx) 244f23b8eeeSSeongJae Park damon_destroy_target(t); 245f23b8eeeSSeongJae Park } 246f23b8eeeSSeongJae Park 2472224d848SSeongJae Park void damon_destroy_ctx(struct damon_ctx *ctx) 2482224d848SSeongJae Park { 2491f366e42SSeongJae Park struct damos *s, *next_s; 2501f366e42SSeongJae Park 251f23b8eeeSSeongJae Park damon_destroy_targets(ctx); 2521f366e42SSeongJae Park 2531f366e42SSeongJae Park damon_for_each_scheme_safe(s, next_s, ctx) 2541f366e42SSeongJae Park damon_destroy_scheme(s); 2551f366e42SSeongJae Park 2562224d848SSeongJae Park kfree(ctx); 2572224d848SSeongJae Park } 2582224d848SSeongJae Park 2592224d848SSeongJae Park /** 2604bc05954SSeongJae Park * damon_set_targets() - Set monitoring targets. 2614bc05954SSeongJae Park * @ctx: monitoring context 2624bc05954SSeongJae Park * @ids: array of target ids 2634bc05954SSeongJae Park * @nr_ids: number of entries in @ids 2644bc05954SSeongJae Park * 2654bc05954SSeongJae Park * This function should not be called while the kdamond is running. 2664bc05954SSeongJae Park * 2674bc05954SSeongJae Park * Return: 0 on success, negative error code otherwise. 2684bc05954SSeongJae Park */ 2694bc05954SSeongJae Park int damon_set_targets(struct damon_ctx *ctx, 2704bc05954SSeongJae Park unsigned long *ids, ssize_t nr_ids) 2714bc05954SSeongJae Park { 2724bc05954SSeongJae Park ssize_t i; 2734bc05954SSeongJae Park struct damon_target *t, *next; 2744bc05954SSeongJae Park 2754bc05954SSeongJae Park damon_destroy_targets(ctx); 2764bc05954SSeongJae Park 2774bc05954SSeongJae Park for (i = 0; i < nr_ids; i++) { 2784bc05954SSeongJae Park t = damon_new_target(ids[i]); 2794bc05954SSeongJae Park if (!t) { 2804bc05954SSeongJae Park /* The caller should do cleanup of the ids itself */ 2814bc05954SSeongJae Park damon_for_each_target_safe(t, next, ctx) 2824bc05954SSeongJae Park damon_destroy_target(t); 2834bc05954SSeongJae Park return -ENOMEM; 2844bc05954SSeongJae Park } 2854bc05954SSeongJae Park damon_add_target(ctx, t); 2864bc05954SSeongJae Park } 2874bc05954SSeongJae Park 2884bc05954SSeongJae Park return 0; 2894bc05954SSeongJae Park } 2904bc05954SSeongJae Park 2914bc05954SSeongJae Park /** 2922224d848SSeongJae Park * damon_set_attrs() - Set attributes for the monitoring. 2932224d848SSeongJae Park * @ctx: monitoring context 2942224d848SSeongJae Park * @sample_int: time interval between samplings 2952224d848SSeongJae Park * @aggr_int: time interval between aggregations 2962224d848SSeongJae Park * @primitive_upd_int: time interval between monitoring primitive updates 297b9a6ac4eSSeongJae Park * @min_nr_reg: minimal number of regions 298b9a6ac4eSSeongJae Park * @max_nr_reg: maximum number of regions 2992224d848SSeongJae Park * 3002224d848SSeongJae Park * This function should not be called while the kdamond is running. 3012224d848SSeongJae Park * Every time interval is in micro-seconds. 3022224d848SSeongJae Park * 3032224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 3042224d848SSeongJae Park */ 3052224d848SSeongJae Park int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int, 306b9a6ac4eSSeongJae Park unsigned long aggr_int, unsigned long primitive_upd_int, 307b9a6ac4eSSeongJae Park unsigned long min_nr_reg, unsigned long max_nr_reg) 3082224d848SSeongJae Park { 3091afaf5cbSSeongJae Park if (min_nr_reg < 3) 310b9a6ac4eSSeongJae Park return -EINVAL; 3111afaf5cbSSeongJae Park if (min_nr_reg > max_nr_reg) 312b9a6ac4eSSeongJae Park return -EINVAL; 313b9a6ac4eSSeongJae Park 3142224d848SSeongJae Park ctx->sample_interval = sample_int; 3152224d848SSeongJae Park ctx->aggr_interval = aggr_int; 3162224d848SSeongJae Park ctx->primitive_update_interval = primitive_upd_int; 317b9a6ac4eSSeongJae Park ctx->min_nr_regions = min_nr_reg; 318b9a6ac4eSSeongJae Park ctx->max_nr_regions = max_nr_reg; 3192224d848SSeongJae Park 3202224d848SSeongJae Park return 0; 3212224d848SSeongJae Park } 3222224d848SSeongJae Park 3234bc05954SSeongJae Park /** 3241f366e42SSeongJae Park * damon_set_schemes() - Set data access monitoring based operation schemes. 3251f366e42SSeongJae Park * @ctx: monitoring context 3261f366e42SSeongJae Park * @schemes: array of the schemes 3271f366e42SSeongJae Park * @nr_schemes: number of entries in @schemes 3281f366e42SSeongJae Park * 3291f366e42SSeongJae Park * This function should not be called while the kdamond of the context is 3301f366e42SSeongJae Park * running. 3311f366e42SSeongJae Park * 3321f366e42SSeongJae Park * Return: 0 if success, or negative error code otherwise. 3331f366e42SSeongJae Park */ 3341f366e42SSeongJae Park int damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, 3351f366e42SSeongJae Park ssize_t nr_schemes) 3361f366e42SSeongJae Park { 3371f366e42SSeongJae Park struct damos *s, *next; 3381f366e42SSeongJae Park ssize_t i; 3391f366e42SSeongJae Park 3401f366e42SSeongJae Park damon_for_each_scheme_safe(s, next, ctx) 3411f366e42SSeongJae Park damon_destroy_scheme(s); 3421f366e42SSeongJae Park for (i = 0; i < nr_schemes; i++) 3431f366e42SSeongJae Park damon_add_scheme(ctx, schemes[i]); 3441f366e42SSeongJae Park return 0; 3451f366e42SSeongJae Park } 3461f366e42SSeongJae Park 3471f366e42SSeongJae Park /** 3484bc05954SSeongJae Park * damon_nr_running_ctxs() - Return number of currently running contexts. 3494bc05954SSeongJae Park */ 3504bc05954SSeongJae Park int damon_nr_running_ctxs(void) 3514bc05954SSeongJae Park { 3524bc05954SSeongJae Park int nr_ctxs; 3534bc05954SSeongJae Park 3544bc05954SSeongJae Park mutex_lock(&damon_lock); 3554bc05954SSeongJae Park nr_ctxs = nr_running_ctxs; 3564bc05954SSeongJae Park mutex_unlock(&damon_lock); 3574bc05954SSeongJae Park 3584bc05954SSeongJae Park return nr_ctxs; 3594bc05954SSeongJae Park } 3604bc05954SSeongJae Park 361b9a6ac4eSSeongJae Park /* Returns the size upper limit for each monitoring region */ 362b9a6ac4eSSeongJae Park static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) 363b9a6ac4eSSeongJae Park { 364b9a6ac4eSSeongJae Park struct damon_target *t; 365b9a6ac4eSSeongJae Park struct damon_region *r; 366b9a6ac4eSSeongJae Park unsigned long sz = 0; 367b9a6ac4eSSeongJae Park 368b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) { 369b9a6ac4eSSeongJae Park damon_for_each_region(r, t) 370b9a6ac4eSSeongJae Park sz += r->ar.end - r->ar.start; 371b9a6ac4eSSeongJae Park } 372b9a6ac4eSSeongJae Park 373b9a6ac4eSSeongJae Park if (ctx->min_nr_regions) 374b9a6ac4eSSeongJae Park sz /= ctx->min_nr_regions; 375b9a6ac4eSSeongJae Park if (sz < DAMON_MIN_REGION) 376b9a6ac4eSSeongJae Park sz = DAMON_MIN_REGION; 377b9a6ac4eSSeongJae Park 378b9a6ac4eSSeongJae Park return sz; 379b9a6ac4eSSeongJae Park } 380b9a6ac4eSSeongJae Park 3812224d848SSeongJae Park static int kdamond_fn(void *data); 3822224d848SSeongJae Park 3832224d848SSeongJae Park /* 3842224d848SSeongJae Park * __damon_start() - Starts monitoring with given context. 3852224d848SSeongJae Park * @ctx: monitoring context 3862224d848SSeongJae Park * 3872224d848SSeongJae Park * This function should be called while damon_lock is hold. 3882224d848SSeongJae Park * 3892224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 3902224d848SSeongJae Park */ 3912224d848SSeongJae Park static int __damon_start(struct damon_ctx *ctx) 3922224d848SSeongJae Park { 3932224d848SSeongJae Park int err = -EBUSY; 3942224d848SSeongJae Park 3952224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 3962224d848SSeongJae Park if (!ctx->kdamond) { 3972224d848SSeongJae Park err = 0; 3982224d848SSeongJae Park ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", 3992224d848SSeongJae Park nr_running_ctxs); 4002224d848SSeongJae Park if (IS_ERR(ctx->kdamond)) { 4012224d848SSeongJae Park err = PTR_ERR(ctx->kdamond); 4027ec1992bSColin Ian King ctx->kdamond = NULL; 4032224d848SSeongJae Park } 4042224d848SSeongJae Park } 4052224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4062224d848SSeongJae Park 4072224d848SSeongJae Park return err; 4082224d848SSeongJae Park } 4092224d848SSeongJae Park 4102224d848SSeongJae Park /** 4112224d848SSeongJae Park * damon_start() - Starts the monitorings for a given group of contexts. 4122224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to start monitoring 4132224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4142224d848SSeongJae Park * 4152224d848SSeongJae Park * This function starts a group of monitoring threads for a group of monitoring 4162224d848SSeongJae Park * contexts. One thread per each context is created and run in parallel. The 4172224d848SSeongJae Park * caller should handle synchronization between the threads by itself. If a 4182224d848SSeongJae Park * group of threads that created by other 'damon_start()' call is currently 4192224d848SSeongJae Park * running, this function does nothing but returns -EBUSY. 4202224d848SSeongJae Park * 4212224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4222224d848SSeongJae Park */ 4232224d848SSeongJae Park int damon_start(struct damon_ctx **ctxs, int nr_ctxs) 4242224d848SSeongJae Park { 4252224d848SSeongJae Park int i; 4262224d848SSeongJae Park int err = 0; 4272224d848SSeongJae Park 4282224d848SSeongJae Park mutex_lock(&damon_lock); 4292224d848SSeongJae Park if (nr_running_ctxs) { 4302224d848SSeongJae Park mutex_unlock(&damon_lock); 4312224d848SSeongJae Park return -EBUSY; 4322224d848SSeongJae Park } 4332224d848SSeongJae Park 4342224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 4352224d848SSeongJae Park err = __damon_start(ctxs[i]); 4362224d848SSeongJae Park if (err) 4372224d848SSeongJae Park break; 4382224d848SSeongJae Park nr_running_ctxs++; 4392224d848SSeongJae Park } 4402224d848SSeongJae Park mutex_unlock(&damon_lock); 4412224d848SSeongJae Park 4422224d848SSeongJae Park return err; 4432224d848SSeongJae Park } 4442224d848SSeongJae Park 4452224d848SSeongJae Park /* 4462224d848SSeongJae Park * __damon_stop() - Stops monitoring of given context. 4472224d848SSeongJae Park * @ctx: monitoring context 4482224d848SSeongJae Park * 4492224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4502224d848SSeongJae Park */ 4512224d848SSeongJae Park static int __damon_stop(struct damon_ctx *ctx) 4522224d848SSeongJae Park { 4530f91d133SChangbin Du struct task_struct *tsk; 4540f91d133SChangbin Du 4552224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 4560f91d133SChangbin Du tsk = ctx->kdamond; 4570f91d133SChangbin Du if (tsk) { 4580f91d133SChangbin Du get_task_struct(tsk); 4592224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4600f91d133SChangbin Du kthread_stop(tsk); 4610f91d133SChangbin Du put_task_struct(tsk); 4622224d848SSeongJae Park return 0; 4632224d848SSeongJae Park } 4642224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4652224d848SSeongJae Park 4662224d848SSeongJae Park return -EPERM; 4672224d848SSeongJae Park } 4682224d848SSeongJae Park 4692224d848SSeongJae Park /** 4702224d848SSeongJae Park * damon_stop() - Stops the monitorings for a given group of contexts. 4712224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to stop monitoring 4722224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4732224d848SSeongJae Park * 4742224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4752224d848SSeongJae Park */ 4762224d848SSeongJae Park int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) 4772224d848SSeongJae Park { 4782224d848SSeongJae Park int i, err = 0; 4792224d848SSeongJae Park 4802224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 4812224d848SSeongJae Park /* nr_running_ctxs is decremented in kdamond_fn */ 4822224d848SSeongJae Park err = __damon_stop(ctxs[i]); 4832224d848SSeongJae Park if (err) 4842224d848SSeongJae Park return err; 4852224d848SSeongJae Park } 4862224d848SSeongJae Park 4872224d848SSeongJae Park return err; 4882224d848SSeongJae Park } 4892224d848SSeongJae Park 4902224d848SSeongJae Park /* 4912224d848SSeongJae Park * damon_check_reset_time_interval() - Check if a time interval is elapsed. 4922224d848SSeongJae Park * @baseline: the time to check whether the interval has elapsed since 4932224d848SSeongJae Park * @interval: the time interval (microseconds) 4942224d848SSeongJae Park * 4952224d848SSeongJae Park * See whether the given time interval has passed since the given baseline 4962224d848SSeongJae Park * time. If so, it also updates the baseline to current time for next check. 4972224d848SSeongJae Park * 4982224d848SSeongJae Park * Return: true if the time interval has passed, or false otherwise. 4992224d848SSeongJae Park */ 5002224d848SSeongJae Park static bool damon_check_reset_time_interval(struct timespec64 *baseline, 5012224d848SSeongJae Park unsigned long interval) 5022224d848SSeongJae Park { 5032224d848SSeongJae Park struct timespec64 now; 5042224d848SSeongJae Park 5052224d848SSeongJae Park ktime_get_coarse_ts64(&now); 5062224d848SSeongJae Park if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) < 5072224d848SSeongJae Park interval * 1000) 5082224d848SSeongJae Park return false; 5092224d848SSeongJae Park *baseline = now; 5102224d848SSeongJae Park return true; 5112224d848SSeongJae Park } 5122224d848SSeongJae Park 5132224d848SSeongJae Park /* 5142224d848SSeongJae Park * Check whether it is time to flush the aggregated information 5152224d848SSeongJae Park */ 5162224d848SSeongJae Park static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) 5172224d848SSeongJae Park { 5182224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_aggregation, 5192224d848SSeongJae Park ctx->aggr_interval); 5202224d848SSeongJae Park } 5212224d848SSeongJae Park 5222224d848SSeongJae Park /* 523f23b8eeeSSeongJae Park * Reset the aggregated monitoring results ('nr_accesses' of each region). 524f23b8eeeSSeongJae Park */ 525f23b8eeeSSeongJae Park static void kdamond_reset_aggregated(struct damon_ctx *c) 526f23b8eeeSSeongJae Park { 527f23b8eeeSSeongJae Park struct damon_target *t; 528f23b8eeeSSeongJae Park 529f23b8eeeSSeongJae Park damon_for_each_target(t, c) { 530f23b8eeeSSeongJae Park struct damon_region *r; 531f23b8eeeSSeongJae Park 5322fcb9362SSeongJae Park damon_for_each_region(r, t) { 5332fcb9362SSeongJae Park trace_damon_aggregated(t, r, damon_nr_regions(t)); 534fda504faSSeongJae Park r->last_nr_accesses = r->nr_accesses; 535f23b8eeeSSeongJae Park r->nr_accesses = 0; 536f23b8eeeSSeongJae Park } 537f23b8eeeSSeongJae Park } 5382fcb9362SSeongJae Park } 539f23b8eeeSSeongJae Park 5402b8a248dSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 5412b8a248dSSeongJae Park struct damon_target *t, struct damon_region *r, 5422b8a248dSSeongJae Park unsigned long sz_r); 5432b8a248dSSeongJae Park 54438683e00SSeongJae Park static bool __damos_valid_target(struct damon_region *r, struct damos *s) 54538683e00SSeongJae Park { 54638683e00SSeongJae Park unsigned long sz; 54738683e00SSeongJae Park 54838683e00SSeongJae Park sz = r->ar.end - r->ar.start; 54938683e00SSeongJae Park return s->min_sz_region <= sz && sz <= s->max_sz_region && 55038683e00SSeongJae Park s->min_nr_accesses <= r->nr_accesses && 55138683e00SSeongJae Park r->nr_accesses <= s->max_nr_accesses && 55238683e00SSeongJae Park s->min_age_region <= r->age && r->age <= s->max_age_region; 55338683e00SSeongJae Park } 55438683e00SSeongJae Park 55538683e00SSeongJae Park static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, 55638683e00SSeongJae Park struct damon_region *r, struct damos *s) 55738683e00SSeongJae Park { 55838683e00SSeongJae Park bool ret = __damos_valid_target(r, s); 55938683e00SSeongJae Park 56038683e00SSeongJae Park if (!ret || !s->quota.esz || !c->primitive.get_scheme_score) 56138683e00SSeongJae Park return ret; 56238683e00SSeongJae Park 56338683e00SSeongJae Park return c->primitive.get_scheme_score(c, t, r, s) >= s->quota.min_score; 56438683e00SSeongJae Park } 56538683e00SSeongJae Park 5661f366e42SSeongJae Park static void damon_do_apply_schemes(struct damon_ctx *c, 5671f366e42SSeongJae Park struct damon_target *t, 5681f366e42SSeongJae Park struct damon_region *r) 5691f366e42SSeongJae Park { 5701f366e42SSeongJae Park struct damos *s; 5711f366e42SSeongJae Park 5721f366e42SSeongJae Park damon_for_each_scheme(s, c) { 5732b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 5742b8a248dSSeongJae Park unsigned long sz = r->ar.end - r->ar.start; 5751cd24303SSeongJae Park struct timespec64 begin, end; 576*0e92c2eeSSeongJae Park unsigned long sz_applied = 0; 5772b8a248dSSeongJae Park 578ee801b7dSSeongJae Park if (!s->wmarks.activated) 579ee801b7dSSeongJae Park continue; 580ee801b7dSSeongJae Park 5812b8a248dSSeongJae Park /* Check the quota */ 5821cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 5832b8a248dSSeongJae Park continue; 5842b8a248dSSeongJae Park 58550585192SSeongJae Park /* Skip previously charged regions */ 58650585192SSeongJae Park if (quota->charge_target_from) { 58750585192SSeongJae Park if (t != quota->charge_target_from) 58850585192SSeongJae Park continue; 58950585192SSeongJae Park if (r == damon_last_region(t)) { 59050585192SSeongJae Park quota->charge_target_from = NULL; 59150585192SSeongJae Park quota->charge_addr_from = 0; 59250585192SSeongJae Park continue; 59350585192SSeongJae Park } 59450585192SSeongJae Park if (quota->charge_addr_from && 59550585192SSeongJae Park r->ar.end <= quota->charge_addr_from) 59650585192SSeongJae Park continue; 59750585192SSeongJae Park 59850585192SSeongJae Park if (quota->charge_addr_from && r->ar.start < 59950585192SSeongJae Park quota->charge_addr_from) { 60050585192SSeongJae Park sz = ALIGN_DOWN(quota->charge_addr_from - 60150585192SSeongJae Park r->ar.start, DAMON_MIN_REGION); 60250585192SSeongJae Park if (!sz) { 60350585192SSeongJae Park if (r->ar.end - r->ar.start <= 60450585192SSeongJae Park DAMON_MIN_REGION) 60550585192SSeongJae Park continue; 60650585192SSeongJae Park sz = DAMON_MIN_REGION; 60750585192SSeongJae Park } 60850585192SSeongJae Park damon_split_region_at(c, t, r, sz); 60950585192SSeongJae Park r = damon_next_region(r); 61050585192SSeongJae Park sz = r->ar.end - r->ar.start; 61150585192SSeongJae Park } 61250585192SSeongJae Park quota->charge_target_from = NULL; 61350585192SSeongJae Park quota->charge_addr_from = 0; 61450585192SSeongJae Park } 61550585192SSeongJae Park 61638683e00SSeongJae Park if (!damos_valid_target(c, t, r, s)) 6171f366e42SSeongJae Park continue; 6182b8a248dSSeongJae Park 6192b8a248dSSeongJae Park /* Apply the scheme */ 6202b8a248dSSeongJae Park if (c->primitive.apply_scheme) { 6211cd24303SSeongJae Park if (quota->esz && 6221cd24303SSeongJae Park quota->charged_sz + sz > quota->esz) { 6231cd24303SSeongJae Park sz = ALIGN_DOWN(quota->esz - quota->charged_sz, 6242b8a248dSSeongJae Park DAMON_MIN_REGION); 6252b8a248dSSeongJae Park if (!sz) 6262b8a248dSSeongJae Park goto update_stat; 6272b8a248dSSeongJae Park damon_split_region_at(c, t, r, sz); 6282b8a248dSSeongJae Park } 6291cd24303SSeongJae Park ktime_get_coarse_ts64(&begin); 630*0e92c2eeSSeongJae Park sz_applied = c->primitive.apply_scheme(c, t, r, s); 6311cd24303SSeongJae Park ktime_get_coarse_ts64(&end); 6321cd24303SSeongJae Park quota->total_charged_ns += timespec64_to_ns(&end) - 6331cd24303SSeongJae Park timespec64_to_ns(&begin); 6342b8a248dSSeongJae Park quota->charged_sz += sz; 6351cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) { 63650585192SSeongJae Park quota->charge_target_from = t; 63750585192SSeongJae Park quota->charge_addr_from = r->ar.end + 1; 63850585192SSeongJae Park } 6392b8a248dSSeongJae Park } 6402f0b548cSSeongJae Park if (s->action != DAMOS_STAT) 6411f366e42SSeongJae Park r->age = 0; 6422b8a248dSSeongJae Park 6432b8a248dSSeongJae Park update_stat: 644*0e92c2eeSSeongJae Park s->stat.nr_tried++; 645*0e92c2eeSSeongJae Park s->stat.sz_tried += sz; 646*0e92c2eeSSeongJae Park if (sz_applied) 647*0e92c2eeSSeongJae Park s->stat.nr_applied++; 648*0e92c2eeSSeongJae Park s->stat.sz_applied += sz_applied; 6491f366e42SSeongJae Park } 6501f366e42SSeongJae Park } 6511f366e42SSeongJae Park 6521cd24303SSeongJae Park /* Shouldn't be called if quota->ms and quota->sz are zero */ 6531cd24303SSeongJae Park static void damos_set_effective_quota(struct damos_quota *quota) 6541cd24303SSeongJae Park { 6551cd24303SSeongJae Park unsigned long throughput; 6561cd24303SSeongJae Park unsigned long esz; 6571cd24303SSeongJae Park 6581cd24303SSeongJae Park if (!quota->ms) { 6591cd24303SSeongJae Park quota->esz = quota->sz; 6601cd24303SSeongJae Park return; 6611cd24303SSeongJae Park } 6621cd24303SSeongJae Park 6631cd24303SSeongJae Park if (quota->total_charged_ns) 6641cd24303SSeongJae Park throughput = quota->total_charged_sz * 1000000 / 6651cd24303SSeongJae Park quota->total_charged_ns; 6661cd24303SSeongJae Park else 6671cd24303SSeongJae Park throughput = PAGE_SIZE * 1024; 6681cd24303SSeongJae Park esz = throughput * quota->ms; 6691cd24303SSeongJae Park 6701cd24303SSeongJae Park if (quota->sz && quota->sz < esz) 6711cd24303SSeongJae Park esz = quota->sz; 6721cd24303SSeongJae Park quota->esz = esz; 6731cd24303SSeongJae Park } 6741cd24303SSeongJae Park 6751f366e42SSeongJae Park static void kdamond_apply_schemes(struct damon_ctx *c) 6761f366e42SSeongJae Park { 6771f366e42SSeongJae Park struct damon_target *t; 6782b8a248dSSeongJae Park struct damon_region *r, *next_r; 6792b8a248dSSeongJae Park struct damos *s; 6802b8a248dSSeongJae Park 6812b8a248dSSeongJae Park damon_for_each_scheme(s, c) { 6822b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 68338683e00SSeongJae Park unsigned long cumulated_sz; 68438683e00SSeongJae Park unsigned int score, max_score = 0; 6852b8a248dSSeongJae Park 686ee801b7dSSeongJae Park if (!s->wmarks.activated) 687ee801b7dSSeongJae Park continue; 688ee801b7dSSeongJae Park 6891cd24303SSeongJae Park if (!quota->ms && !quota->sz) 6902b8a248dSSeongJae Park continue; 6912b8a248dSSeongJae Park 6922b8a248dSSeongJae Park /* New charge window starts */ 6932b8a248dSSeongJae Park if (time_after_eq(jiffies, quota->charged_from + 6942b8a248dSSeongJae Park msecs_to_jiffies( 6952b8a248dSSeongJae Park quota->reset_interval))) { 6961cd24303SSeongJae Park quota->total_charged_sz += quota->charged_sz; 6972b8a248dSSeongJae Park quota->charged_from = jiffies; 6982b8a248dSSeongJae Park quota->charged_sz = 0; 6991cd24303SSeongJae Park damos_set_effective_quota(quota); 7002b8a248dSSeongJae Park } 70138683e00SSeongJae Park 70238683e00SSeongJae Park if (!c->primitive.get_scheme_score) 70338683e00SSeongJae Park continue; 70438683e00SSeongJae Park 70538683e00SSeongJae Park /* Fill up the score histogram */ 70638683e00SSeongJae Park memset(quota->histogram, 0, sizeof(quota->histogram)); 70738683e00SSeongJae Park damon_for_each_target(t, c) { 70838683e00SSeongJae Park damon_for_each_region(r, t) { 70938683e00SSeongJae Park if (!__damos_valid_target(r, s)) 71038683e00SSeongJae Park continue; 71138683e00SSeongJae Park score = c->primitive.get_scheme_score( 71238683e00SSeongJae Park c, t, r, s); 71338683e00SSeongJae Park quota->histogram[score] += 71438683e00SSeongJae Park r->ar.end - r->ar.start; 71538683e00SSeongJae Park if (score > max_score) 71638683e00SSeongJae Park max_score = score; 71738683e00SSeongJae Park } 71838683e00SSeongJae Park } 71938683e00SSeongJae Park 72038683e00SSeongJae Park /* Set the min score limit */ 72138683e00SSeongJae Park for (cumulated_sz = 0, score = max_score; ; score--) { 72238683e00SSeongJae Park cumulated_sz += quota->histogram[score]; 72338683e00SSeongJae Park if (cumulated_sz >= quota->esz || !score) 72438683e00SSeongJae Park break; 72538683e00SSeongJae Park } 72638683e00SSeongJae Park quota->min_score = score; 7272b8a248dSSeongJae Park } 7281f366e42SSeongJae Park 7291f366e42SSeongJae Park damon_for_each_target(t, c) { 7302b8a248dSSeongJae Park damon_for_each_region_safe(r, next_r, t) 7311f366e42SSeongJae Park damon_do_apply_schemes(c, t, r); 7321f366e42SSeongJae Park } 7331f366e42SSeongJae Park } 7341f366e42SSeongJae Park 73588f86dcfSSeongJae Park static inline unsigned long sz_damon_region(struct damon_region *r) 73688f86dcfSSeongJae Park { 73788f86dcfSSeongJae Park return r->ar.end - r->ar.start; 73888f86dcfSSeongJae Park } 739b9a6ac4eSSeongJae Park 740b9a6ac4eSSeongJae Park /* 741b9a6ac4eSSeongJae Park * Merge two adjacent regions into one region 742b9a6ac4eSSeongJae Park */ 743b9a6ac4eSSeongJae Park static void damon_merge_two_regions(struct damon_target *t, 744b9a6ac4eSSeongJae Park struct damon_region *l, struct damon_region *r) 745b9a6ac4eSSeongJae Park { 746b9a6ac4eSSeongJae Park unsigned long sz_l = sz_damon_region(l), sz_r = sz_damon_region(r); 747b9a6ac4eSSeongJae Park 748b9a6ac4eSSeongJae Park l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / 749b9a6ac4eSSeongJae Park (sz_l + sz_r); 750fda504faSSeongJae Park l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); 751b9a6ac4eSSeongJae Park l->ar.end = r->ar.end; 752b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 753b9a6ac4eSSeongJae Park } 754b9a6ac4eSSeongJae Park 755b9a6ac4eSSeongJae Park /* 756b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 757b9a6ac4eSSeongJae Park * 758b9a6ac4eSSeongJae Park * t target affected by this merge operation 759b9a6ac4eSSeongJae Park * thres '->nr_accesses' diff threshold for the merge 760b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 761b9a6ac4eSSeongJae Park */ 762b9a6ac4eSSeongJae Park static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, 763b9a6ac4eSSeongJae Park unsigned long sz_limit) 764b9a6ac4eSSeongJae Park { 765b9a6ac4eSSeongJae Park struct damon_region *r, *prev = NULL, *next; 766b9a6ac4eSSeongJae Park 767b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 768d720bbbdSXin Hao if (abs(r->nr_accesses - r->last_nr_accesses) > thres) 769fda504faSSeongJae Park r->age = 0; 770fda504faSSeongJae Park else 771fda504faSSeongJae Park r->age++; 772fda504faSSeongJae Park 773b9a6ac4eSSeongJae Park if (prev && prev->ar.end == r->ar.start && 774d720bbbdSXin Hao abs(prev->nr_accesses - r->nr_accesses) <= thres && 775b9a6ac4eSSeongJae Park sz_damon_region(prev) + sz_damon_region(r) <= sz_limit) 776b9a6ac4eSSeongJae Park damon_merge_two_regions(t, prev, r); 777b9a6ac4eSSeongJae Park else 778b9a6ac4eSSeongJae Park prev = r; 779b9a6ac4eSSeongJae Park } 780b9a6ac4eSSeongJae Park } 781b9a6ac4eSSeongJae Park 782b9a6ac4eSSeongJae Park /* 783b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 784b9a6ac4eSSeongJae Park * 785b9a6ac4eSSeongJae Park * threshold '->nr_accesses' diff threshold for the merge 786b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 787b9a6ac4eSSeongJae Park * 788b9a6ac4eSSeongJae Park * This function merges monitoring target regions which are adjacent and their 789b9a6ac4eSSeongJae Park * access frequencies are similar. This is for minimizing the monitoring 790b9a6ac4eSSeongJae Park * overhead under the dynamically changeable access pattern. If a merge was 791b9a6ac4eSSeongJae Park * unnecessarily made, later 'kdamond_split_regions()' will revert it. 792b9a6ac4eSSeongJae Park */ 793b9a6ac4eSSeongJae Park static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, 794b9a6ac4eSSeongJae Park unsigned long sz_limit) 795b9a6ac4eSSeongJae Park { 796b9a6ac4eSSeongJae Park struct damon_target *t; 797b9a6ac4eSSeongJae Park 798b9a6ac4eSSeongJae Park damon_for_each_target(t, c) 799b9a6ac4eSSeongJae Park damon_merge_regions_of(t, threshold, sz_limit); 800b9a6ac4eSSeongJae Park } 801b9a6ac4eSSeongJae Park 802b9a6ac4eSSeongJae Park /* 803b9a6ac4eSSeongJae Park * Split a region in two 804b9a6ac4eSSeongJae Park * 805b9a6ac4eSSeongJae Park * r the region to be split 806b9a6ac4eSSeongJae Park * sz_r size of the first sub-region that will be made 807b9a6ac4eSSeongJae Park */ 808b9a6ac4eSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 809b9a6ac4eSSeongJae Park struct damon_target *t, struct damon_region *r, 810b9a6ac4eSSeongJae Park unsigned long sz_r) 811b9a6ac4eSSeongJae Park { 812b9a6ac4eSSeongJae Park struct damon_region *new; 813b9a6ac4eSSeongJae Park 814b9a6ac4eSSeongJae Park new = damon_new_region(r->ar.start + sz_r, r->ar.end); 815b9a6ac4eSSeongJae Park if (!new) 816b9a6ac4eSSeongJae Park return; 817b9a6ac4eSSeongJae Park 818b9a6ac4eSSeongJae Park r->ar.end = new->ar.start; 819b9a6ac4eSSeongJae Park 820fda504faSSeongJae Park new->age = r->age; 821fda504faSSeongJae Park new->last_nr_accesses = r->last_nr_accesses; 822fda504faSSeongJae Park 823b9a6ac4eSSeongJae Park damon_insert_region(new, r, damon_next_region(r), t); 824b9a6ac4eSSeongJae Park } 825b9a6ac4eSSeongJae Park 826b9a6ac4eSSeongJae Park /* Split every region in the given target into 'nr_subs' regions */ 827b9a6ac4eSSeongJae Park static void damon_split_regions_of(struct damon_ctx *ctx, 828b9a6ac4eSSeongJae Park struct damon_target *t, int nr_subs) 829b9a6ac4eSSeongJae Park { 830b9a6ac4eSSeongJae Park struct damon_region *r, *next; 831b9a6ac4eSSeongJae Park unsigned long sz_region, sz_sub = 0; 832b9a6ac4eSSeongJae Park int i; 833b9a6ac4eSSeongJae Park 834b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 835b9a6ac4eSSeongJae Park sz_region = r->ar.end - r->ar.start; 836b9a6ac4eSSeongJae Park 837b9a6ac4eSSeongJae Park for (i = 0; i < nr_subs - 1 && 838b9a6ac4eSSeongJae Park sz_region > 2 * DAMON_MIN_REGION; i++) { 839b9a6ac4eSSeongJae Park /* 840b9a6ac4eSSeongJae Park * Randomly select size of left sub-region to be at 841b9a6ac4eSSeongJae Park * least 10 percent and at most 90% of original region 842b9a6ac4eSSeongJae Park */ 843b9a6ac4eSSeongJae Park sz_sub = ALIGN_DOWN(damon_rand(1, 10) * 844b9a6ac4eSSeongJae Park sz_region / 10, DAMON_MIN_REGION); 845b9a6ac4eSSeongJae Park /* Do not allow blank region */ 846b9a6ac4eSSeongJae Park if (sz_sub == 0 || sz_sub >= sz_region) 847b9a6ac4eSSeongJae Park continue; 848b9a6ac4eSSeongJae Park 849b9a6ac4eSSeongJae Park damon_split_region_at(ctx, t, r, sz_sub); 850b9a6ac4eSSeongJae Park sz_region = sz_sub; 851b9a6ac4eSSeongJae Park } 852b9a6ac4eSSeongJae Park } 853b9a6ac4eSSeongJae Park } 854b9a6ac4eSSeongJae Park 855b9a6ac4eSSeongJae Park /* 856b9a6ac4eSSeongJae Park * Split every target region into randomly-sized small regions 857b9a6ac4eSSeongJae Park * 858b9a6ac4eSSeongJae Park * This function splits every target region into random-sized small regions if 859b9a6ac4eSSeongJae Park * current total number of the regions is equal or smaller than half of the 860b9a6ac4eSSeongJae Park * user-specified maximum number of regions. This is for maximizing the 861b9a6ac4eSSeongJae Park * monitoring accuracy under the dynamically changeable access patterns. If a 862b9a6ac4eSSeongJae Park * split was unnecessarily made, later 'kdamond_merge_regions()' will revert 863b9a6ac4eSSeongJae Park * it. 864b9a6ac4eSSeongJae Park */ 865b9a6ac4eSSeongJae Park static void kdamond_split_regions(struct damon_ctx *ctx) 866b9a6ac4eSSeongJae Park { 867b9a6ac4eSSeongJae Park struct damon_target *t; 868b9a6ac4eSSeongJae Park unsigned int nr_regions = 0; 869b9a6ac4eSSeongJae Park static unsigned int last_nr_regions; 870b9a6ac4eSSeongJae Park int nr_subregions = 2; 871b9a6ac4eSSeongJae Park 872b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 873b9a6ac4eSSeongJae Park nr_regions += damon_nr_regions(t); 874b9a6ac4eSSeongJae Park 875b9a6ac4eSSeongJae Park if (nr_regions > ctx->max_nr_regions / 2) 876b9a6ac4eSSeongJae Park return; 877b9a6ac4eSSeongJae Park 878b9a6ac4eSSeongJae Park /* Maybe the middle of the region has different access frequency */ 879b9a6ac4eSSeongJae Park if (last_nr_regions == nr_regions && 880b9a6ac4eSSeongJae Park nr_regions < ctx->max_nr_regions / 3) 881b9a6ac4eSSeongJae Park nr_subregions = 3; 882b9a6ac4eSSeongJae Park 883b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 884b9a6ac4eSSeongJae Park damon_split_regions_of(ctx, t, nr_subregions); 885b9a6ac4eSSeongJae Park 886b9a6ac4eSSeongJae Park last_nr_regions = nr_regions; 887b9a6ac4eSSeongJae Park } 888b9a6ac4eSSeongJae Park 889f23b8eeeSSeongJae Park /* 8902224d848SSeongJae Park * Check whether it is time to check and apply the target monitoring regions 8912224d848SSeongJae Park * 8922224d848SSeongJae Park * Returns true if it is. 8932224d848SSeongJae Park */ 8942224d848SSeongJae Park static bool kdamond_need_update_primitive(struct damon_ctx *ctx) 8952224d848SSeongJae Park { 8962224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_primitive_update, 8972224d848SSeongJae Park ctx->primitive_update_interval); 8982224d848SSeongJae Park } 8992224d848SSeongJae Park 9002224d848SSeongJae Park /* 9012224d848SSeongJae Park * Check whether current monitoring should be stopped 9022224d848SSeongJae Park * 9032224d848SSeongJae Park * The monitoring is stopped when either the user requested to stop, or all 9042224d848SSeongJae Park * monitoring targets are invalid. 9052224d848SSeongJae Park * 9062224d848SSeongJae Park * Returns true if need to stop current monitoring. 9072224d848SSeongJae Park */ 9082224d848SSeongJae Park static bool kdamond_need_stop(struct damon_ctx *ctx) 9092224d848SSeongJae Park { 910f23b8eeeSSeongJae Park struct damon_target *t; 9112224d848SSeongJae Park 9120f91d133SChangbin Du if (kthread_should_stop()) 9132224d848SSeongJae Park return true; 9142224d848SSeongJae Park 9152224d848SSeongJae Park if (!ctx->primitive.target_valid) 9162224d848SSeongJae Park return false; 9172224d848SSeongJae Park 918f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 919f23b8eeeSSeongJae Park if (ctx->primitive.target_valid(t)) 920f23b8eeeSSeongJae Park return false; 921f23b8eeeSSeongJae Park } 922f23b8eeeSSeongJae Park 923f23b8eeeSSeongJae Park return true; 9242224d848SSeongJae Park } 9252224d848SSeongJae Park 926ee801b7dSSeongJae Park static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) 927ee801b7dSSeongJae Park { 928ee801b7dSSeongJae Park struct sysinfo i; 929ee801b7dSSeongJae Park 930ee801b7dSSeongJae Park switch (metric) { 931ee801b7dSSeongJae Park case DAMOS_WMARK_FREE_MEM_RATE: 932ee801b7dSSeongJae Park si_meminfo(&i); 933ee801b7dSSeongJae Park return i.freeram * 1000 / i.totalram; 934ee801b7dSSeongJae Park default: 935ee801b7dSSeongJae Park break; 936ee801b7dSSeongJae Park } 937ee801b7dSSeongJae Park return -EINVAL; 938ee801b7dSSeongJae Park } 939ee801b7dSSeongJae Park 940ee801b7dSSeongJae Park /* 941ee801b7dSSeongJae Park * Returns zero if the scheme is active. Else, returns time to wait for next 942ee801b7dSSeongJae Park * watermark check in micro-seconds. 943ee801b7dSSeongJae Park */ 944ee801b7dSSeongJae Park static unsigned long damos_wmark_wait_us(struct damos *scheme) 945ee801b7dSSeongJae Park { 946ee801b7dSSeongJae Park unsigned long metric; 947ee801b7dSSeongJae Park 948ee801b7dSSeongJae Park if (scheme->wmarks.metric == DAMOS_WMARK_NONE) 949ee801b7dSSeongJae Park return 0; 950ee801b7dSSeongJae Park 951ee801b7dSSeongJae Park metric = damos_wmark_metric_value(scheme->wmarks.metric); 952ee801b7dSSeongJae Park /* higher than high watermark or lower than low watermark */ 953ee801b7dSSeongJae Park if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { 954ee801b7dSSeongJae Park if (scheme->wmarks.activated) 95501078655SColin Ian King pr_debug("deactivate a scheme (%d) for %s wmark\n", 956ee801b7dSSeongJae Park scheme->action, 957ee801b7dSSeongJae Park metric > scheme->wmarks.high ? 958ee801b7dSSeongJae Park "high" : "low"); 959ee801b7dSSeongJae Park scheme->wmarks.activated = false; 960ee801b7dSSeongJae Park return scheme->wmarks.interval; 961ee801b7dSSeongJae Park } 962ee801b7dSSeongJae Park 963ee801b7dSSeongJae Park /* inactive and higher than middle watermark */ 964ee801b7dSSeongJae Park if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && 965ee801b7dSSeongJae Park !scheme->wmarks.activated) 966ee801b7dSSeongJae Park return scheme->wmarks.interval; 967ee801b7dSSeongJae Park 968ee801b7dSSeongJae Park if (!scheme->wmarks.activated) 969ee801b7dSSeongJae Park pr_debug("activate a scheme (%d)\n", scheme->action); 970ee801b7dSSeongJae Park scheme->wmarks.activated = true; 971ee801b7dSSeongJae Park return 0; 972ee801b7dSSeongJae Park } 973ee801b7dSSeongJae Park 974ee801b7dSSeongJae Park static void kdamond_usleep(unsigned long usecs) 975ee801b7dSSeongJae Park { 9764de46a30SSeongJae Park /* See Documentation/timers/timers-howto.rst for the thresholds */ 9774de46a30SSeongJae Park if (usecs > 20 * USEC_PER_MSEC) 97870e92748SSeongJae Park schedule_timeout_idle(usecs_to_jiffies(usecs)); 979ee801b7dSSeongJae Park else 98070e92748SSeongJae Park usleep_idle_range(usecs, usecs + 1); 981ee801b7dSSeongJae Park } 982ee801b7dSSeongJae Park 983ee801b7dSSeongJae Park /* Returns negative error code if it's not activated but should return */ 984ee801b7dSSeongJae Park static int kdamond_wait_activation(struct damon_ctx *ctx) 985ee801b7dSSeongJae Park { 986ee801b7dSSeongJae Park struct damos *s; 987ee801b7dSSeongJae Park unsigned long wait_time; 988ee801b7dSSeongJae Park unsigned long min_wait_time = 0; 989ee801b7dSSeongJae Park 990ee801b7dSSeongJae Park while (!kdamond_need_stop(ctx)) { 991ee801b7dSSeongJae Park damon_for_each_scheme(s, ctx) { 992ee801b7dSSeongJae Park wait_time = damos_wmark_wait_us(s); 993ee801b7dSSeongJae Park if (!min_wait_time || wait_time < min_wait_time) 994ee801b7dSSeongJae Park min_wait_time = wait_time; 995ee801b7dSSeongJae Park } 996ee801b7dSSeongJae Park if (!min_wait_time) 997ee801b7dSSeongJae Park return 0; 998ee801b7dSSeongJae Park 999ee801b7dSSeongJae Park kdamond_usleep(min_wait_time); 1000ee801b7dSSeongJae Park } 1001ee801b7dSSeongJae Park return -EBUSY; 1002ee801b7dSSeongJae Park } 1003ee801b7dSSeongJae Park 10042224d848SSeongJae Park /* 10052224d848SSeongJae Park * The monitoring daemon that runs as a kernel thread 10062224d848SSeongJae Park */ 10072224d848SSeongJae Park static int kdamond_fn(void *data) 10082224d848SSeongJae Park { 10092224d848SSeongJae Park struct damon_ctx *ctx = (struct damon_ctx *)data; 1010f23b8eeeSSeongJae Park struct damon_target *t; 1011f23b8eeeSSeongJae Park struct damon_region *r, *next; 1012b9a6ac4eSSeongJae Park unsigned int max_nr_accesses = 0; 1013b9a6ac4eSSeongJae Park unsigned long sz_limit = 0; 10140f91d133SChangbin Du bool done = false; 10152224d848SSeongJae Park 101642e4cef5SChangbin Du pr_debug("kdamond (%d) starts\n", current->pid); 10172224d848SSeongJae Park 10182224d848SSeongJae Park if (ctx->primitive.init) 10192224d848SSeongJae Park ctx->primitive.init(ctx); 10202224d848SSeongJae Park if (ctx->callback.before_start && ctx->callback.before_start(ctx)) 10210f91d133SChangbin Du done = true; 10222224d848SSeongJae Park 1023b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 1024b9a6ac4eSSeongJae Park 10250f91d133SChangbin Du while (!kdamond_need_stop(ctx) && !done) { 1026ee801b7dSSeongJae Park if (kdamond_wait_activation(ctx)) 1027ee801b7dSSeongJae Park continue; 1028ee801b7dSSeongJae Park 10292224d848SSeongJae Park if (ctx->primitive.prepare_access_checks) 10302224d848SSeongJae Park ctx->primitive.prepare_access_checks(ctx); 10312224d848SSeongJae Park if (ctx->callback.after_sampling && 10322224d848SSeongJae Park ctx->callback.after_sampling(ctx)) 10330f91d133SChangbin Du done = true; 10342224d848SSeongJae Park 103570e92748SSeongJae Park kdamond_usleep(ctx->sample_interval); 10362224d848SSeongJae Park 10372224d848SSeongJae Park if (ctx->primitive.check_accesses) 1038b9a6ac4eSSeongJae Park max_nr_accesses = ctx->primitive.check_accesses(ctx); 10392224d848SSeongJae Park 10402224d848SSeongJae Park if (kdamond_aggregate_interval_passed(ctx)) { 1041b9a6ac4eSSeongJae Park kdamond_merge_regions(ctx, 1042b9a6ac4eSSeongJae Park max_nr_accesses / 10, 1043b9a6ac4eSSeongJae Park sz_limit); 10442224d848SSeongJae Park if (ctx->callback.after_aggregation && 10452224d848SSeongJae Park ctx->callback.after_aggregation(ctx)) 10460f91d133SChangbin Du done = true; 10471f366e42SSeongJae Park kdamond_apply_schemes(ctx); 1048f23b8eeeSSeongJae Park kdamond_reset_aggregated(ctx); 1049b9a6ac4eSSeongJae Park kdamond_split_regions(ctx); 10502224d848SSeongJae Park if (ctx->primitive.reset_aggregated) 10512224d848SSeongJae Park ctx->primitive.reset_aggregated(ctx); 10522224d848SSeongJae Park } 10532224d848SSeongJae Park 10542224d848SSeongJae Park if (kdamond_need_update_primitive(ctx)) { 10552224d848SSeongJae Park if (ctx->primitive.update) 10562224d848SSeongJae Park ctx->primitive.update(ctx); 1057b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 10582224d848SSeongJae Park } 10592224d848SSeongJae Park } 1060f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 1061f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 1062b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 1063f23b8eeeSSeongJae Park } 10642224d848SSeongJae Park 10650f91d133SChangbin Du if (ctx->callback.before_terminate) 10660f91d133SChangbin Du ctx->callback.before_terminate(ctx); 10672224d848SSeongJae Park if (ctx->primitive.cleanup) 10682224d848SSeongJae Park ctx->primitive.cleanup(ctx); 10692224d848SSeongJae Park 107042e4cef5SChangbin Du pr_debug("kdamond (%d) finishes\n", current->pid); 10712224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 10722224d848SSeongJae Park ctx->kdamond = NULL; 10732224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 10742224d848SSeongJae Park 10752224d848SSeongJae Park mutex_lock(&damon_lock); 10762224d848SSeongJae Park nr_running_ctxs--; 10772224d848SSeongJae Park mutex_unlock(&damon_lock); 10782224d848SSeongJae Park 10795f7fe2b9SChangbin Du return 0; 10802224d848SSeongJae Park } 108117ccae8bSSeongJae Park 108217ccae8bSSeongJae Park #include "core-test.h" 1083