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 28*9f7b053aSSeongJae Park static DEFINE_MUTEX(damon_ops_lock); 29*9f7b053aSSeongJae Park static struct damon_operations damon_registered_ops[NR_DAMON_OPS]; 30*9f7b053aSSeongJae Park 31*9f7b053aSSeongJae Park /* Should be called under damon_ops_lock with id smaller than NR_DAMON_OPS */ 32*9f7b053aSSeongJae Park static bool damon_registered_ops_id(enum damon_ops_id id) 33*9f7b053aSSeongJae Park { 34*9f7b053aSSeongJae Park struct damon_operations empty_ops = {}; 35*9f7b053aSSeongJae Park 36*9f7b053aSSeongJae Park if (!memcmp(&empty_ops, &damon_registered_ops[id], sizeof(empty_ops))) 37*9f7b053aSSeongJae Park return false; 38*9f7b053aSSeongJae Park return true; 39*9f7b053aSSeongJae Park } 40*9f7b053aSSeongJae Park 41*9f7b053aSSeongJae Park /** 42*9f7b053aSSeongJae Park * damon_register_ops() - Register a monitoring operations set to DAMON. 43*9f7b053aSSeongJae Park * @ops: monitoring operations set to register. 44*9f7b053aSSeongJae Park * 45*9f7b053aSSeongJae Park * This function registers a monitoring operations set of valid &struct 46*9f7b053aSSeongJae Park * damon_operations->id so that others can find and use them later. 47*9f7b053aSSeongJae Park * 48*9f7b053aSSeongJae Park * Return: 0 on success, negative error code otherwise. 49*9f7b053aSSeongJae Park */ 50*9f7b053aSSeongJae Park int damon_register_ops(struct damon_operations *ops) 51*9f7b053aSSeongJae Park { 52*9f7b053aSSeongJae Park int err = 0; 53*9f7b053aSSeongJae Park 54*9f7b053aSSeongJae Park if (ops->id >= NR_DAMON_OPS) 55*9f7b053aSSeongJae Park return -EINVAL; 56*9f7b053aSSeongJae Park mutex_lock(&damon_ops_lock); 57*9f7b053aSSeongJae Park /* Fail for already registered ops */ 58*9f7b053aSSeongJae Park if (damon_registered_ops_id(ops->id)) { 59*9f7b053aSSeongJae Park err = -EINVAL; 60*9f7b053aSSeongJae Park goto out; 61*9f7b053aSSeongJae Park } 62*9f7b053aSSeongJae Park damon_registered_ops[ops->id] = *ops; 63*9f7b053aSSeongJae Park out: 64*9f7b053aSSeongJae Park mutex_unlock(&damon_ops_lock); 65*9f7b053aSSeongJae Park return err; 66*9f7b053aSSeongJae Park } 67*9f7b053aSSeongJae Park 68*9f7b053aSSeongJae Park /** 69*9f7b053aSSeongJae Park * damon_select_ops() - Select a monitoring operations to use with the context. 70*9f7b053aSSeongJae Park * @ctx: monitoring context to use the operations. 71*9f7b053aSSeongJae Park * @id: id of the registered monitoring operations to select. 72*9f7b053aSSeongJae Park * 73*9f7b053aSSeongJae Park * This function finds registered monitoring operations set of @id and make 74*9f7b053aSSeongJae Park * @ctx to use it. 75*9f7b053aSSeongJae Park * 76*9f7b053aSSeongJae Park * Return: 0 on success, negative error code otherwise. 77*9f7b053aSSeongJae Park */ 78*9f7b053aSSeongJae Park int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id) 79*9f7b053aSSeongJae Park { 80*9f7b053aSSeongJae Park int err = 0; 81*9f7b053aSSeongJae Park 82*9f7b053aSSeongJae Park if (id >= NR_DAMON_OPS) 83*9f7b053aSSeongJae Park return -EINVAL; 84*9f7b053aSSeongJae Park 85*9f7b053aSSeongJae Park mutex_lock(&damon_ops_lock); 86*9f7b053aSSeongJae Park if (!damon_registered_ops_id(id)) 87*9f7b053aSSeongJae Park err = -EINVAL; 88*9f7b053aSSeongJae Park else 89*9f7b053aSSeongJae Park ctx->ops = damon_registered_ops[id]; 90*9f7b053aSSeongJae Park mutex_unlock(&damon_ops_lock); 91*9f7b053aSSeongJae Park return err; 92*9f7b053aSSeongJae Park } 93*9f7b053aSSeongJae Park 94f23b8eeeSSeongJae Park /* 95f23b8eeeSSeongJae Park * Construct a damon_region struct 96f23b8eeeSSeongJae Park * 97f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 98f23b8eeeSSeongJae Park */ 99f23b8eeeSSeongJae Park struct damon_region *damon_new_region(unsigned long start, unsigned long end) 100f23b8eeeSSeongJae Park { 101f23b8eeeSSeongJae Park struct damon_region *region; 102f23b8eeeSSeongJae Park 103f23b8eeeSSeongJae Park region = kmalloc(sizeof(*region), GFP_KERNEL); 104f23b8eeeSSeongJae Park if (!region) 105f23b8eeeSSeongJae Park return NULL; 106f23b8eeeSSeongJae Park 107f23b8eeeSSeongJae Park region->ar.start = start; 108f23b8eeeSSeongJae Park region->ar.end = end; 109f23b8eeeSSeongJae Park region->nr_accesses = 0; 110f23b8eeeSSeongJae Park INIT_LIST_HEAD(®ion->list); 111f23b8eeeSSeongJae Park 112fda504faSSeongJae Park region->age = 0; 113fda504faSSeongJae Park region->last_nr_accesses = 0; 114fda504faSSeongJae Park 115f23b8eeeSSeongJae Park return region; 116f23b8eeeSSeongJae Park } 117f23b8eeeSSeongJae Park 118f23b8eeeSSeongJae Park void damon_add_region(struct damon_region *r, struct damon_target *t) 119f23b8eeeSSeongJae Park { 120f23b8eeeSSeongJae Park list_add_tail(&r->list, &t->regions_list); 121b9a6ac4eSSeongJae Park t->nr_regions++; 122f23b8eeeSSeongJae Park } 123f23b8eeeSSeongJae Park 124b9a6ac4eSSeongJae Park static void damon_del_region(struct damon_region *r, struct damon_target *t) 125f23b8eeeSSeongJae Park { 126f23b8eeeSSeongJae Park list_del(&r->list); 127b9a6ac4eSSeongJae Park t->nr_regions--; 128f23b8eeeSSeongJae Park } 129f23b8eeeSSeongJae Park 130f23b8eeeSSeongJae Park static void damon_free_region(struct damon_region *r) 131f23b8eeeSSeongJae Park { 132f23b8eeeSSeongJae Park kfree(r); 133f23b8eeeSSeongJae Park } 134f23b8eeeSSeongJae Park 135b9a6ac4eSSeongJae Park void damon_destroy_region(struct damon_region *r, struct damon_target *t) 136f23b8eeeSSeongJae Park { 137b9a6ac4eSSeongJae Park damon_del_region(r, t); 138f23b8eeeSSeongJae Park damon_free_region(r); 139f23b8eeeSSeongJae Park } 140f23b8eeeSSeongJae Park 1411f366e42SSeongJae Park struct damos *damon_new_scheme( 1421f366e42SSeongJae Park unsigned long min_sz_region, unsigned long max_sz_region, 1431f366e42SSeongJae Park unsigned int min_nr_accesses, unsigned int max_nr_accesses, 1441f366e42SSeongJae Park unsigned int min_age_region, unsigned int max_age_region, 145ee801b7dSSeongJae Park enum damos_action action, struct damos_quota *quota, 146ee801b7dSSeongJae Park struct damos_watermarks *wmarks) 1471f366e42SSeongJae Park { 1481f366e42SSeongJae Park struct damos *scheme; 1491f366e42SSeongJae Park 1501f366e42SSeongJae Park scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); 1511f366e42SSeongJae Park if (!scheme) 1521f366e42SSeongJae Park return NULL; 1531f366e42SSeongJae Park scheme->min_sz_region = min_sz_region; 1541f366e42SSeongJae Park scheme->max_sz_region = max_sz_region; 1551f366e42SSeongJae Park scheme->min_nr_accesses = min_nr_accesses; 1561f366e42SSeongJae Park scheme->max_nr_accesses = max_nr_accesses; 1571f366e42SSeongJae Park scheme->min_age_region = min_age_region; 1581f366e42SSeongJae Park scheme->max_age_region = max_age_region; 1591f366e42SSeongJae Park scheme->action = action; 1600e92c2eeSSeongJae Park scheme->stat = (struct damos_stat){}; 1611f366e42SSeongJae Park INIT_LIST_HEAD(&scheme->list); 1621f366e42SSeongJae Park 1631cd24303SSeongJae Park scheme->quota.ms = quota->ms; 1642b8a248dSSeongJae Park scheme->quota.sz = quota->sz; 1652b8a248dSSeongJae Park scheme->quota.reset_interval = quota->reset_interval; 16638683e00SSeongJae Park scheme->quota.weight_sz = quota->weight_sz; 16738683e00SSeongJae Park scheme->quota.weight_nr_accesses = quota->weight_nr_accesses; 16838683e00SSeongJae Park scheme->quota.weight_age = quota->weight_age; 1691cd24303SSeongJae Park scheme->quota.total_charged_sz = 0; 1701cd24303SSeongJae Park scheme->quota.total_charged_ns = 0; 1711cd24303SSeongJae Park scheme->quota.esz = 0; 1722b8a248dSSeongJae Park scheme->quota.charged_sz = 0; 1732b8a248dSSeongJae Park scheme->quota.charged_from = 0; 17450585192SSeongJae Park scheme->quota.charge_target_from = NULL; 17550585192SSeongJae Park scheme->quota.charge_addr_from = 0; 1762b8a248dSSeongJae Park 177ee801b7dSSeongJae Park scheme->wmarks.metric = wmarks->metric; 178ee801b7dSSeongJae Park scheme->wmarks.interval = wmarks->interval; 179ee801b7dSSeongJae Park scheme->wmarks.high = wmarks->high; 180ee801b7dSSeongJae Park scheme->wmarks.mid = wmarks->mid; 181ee801b7dSSeongJae Park scheme->wmarks.low = wmarks->low; 182ee801b7dSSeongJae Park scheme->wmarks.activated = true; 183ee801b7dSSeongJae Park 1841f366e42SSeongJae Park return scheme; 1851f366e42SSeongJae Park } 1861f366e42SSeongJae Park 1871f366e42SSeongJae Park void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) 1881f366e42SSeongJae Park { 1891f366e42SSeongJae Park list_add_tail(&s->list, &ctx->schemes); 1901f366e42SSeongJae Park } 1911f366e42SSeongJae Park 1921f366e42SSeongJae Park static void damon_del_scheme(struct damos *s) 1931f366e42SSeongJae Park { 1941f366e42SSeongJae Park list_del(&s->list); 1951f366e42SSeongJae Park } 1961f366e42SSeongJae Park 1971f366e42SSeongJae Park static void damon_free_scheme(struct damos *s) 1981f366e42SSeongJae Park { 1991f366e42SSeongJae Park kfree(s); 2001f366e42SSeongJae Park } 2011f366e42SSeongJae Park 2021f366e42SSeongJae Park void damon_destroy_scheme(struct damos *s) 2031f366e42SSeongJae Park { 2041f366e42SSeongJae Park damon_del_scheme(s); 2051f366e42SSeongJae Park damon_free_scheme(s); 2061f366e42SSeongJae Park } 2071f366e42SSeongJae Park 208f23b8eeeSSeongJae Park /* 209f23b8eeeSSeongJae Park * Construct a damon_target struct 210f23b8eeeSSeongJae Park * 211f23b8eeeSSeongJae Park * Returns the pointer to the new struct if success, or NULL otherwise 212f23b8eeeSSeongJae Park */ 2131971bd63SSeongJae Park struct damon_target *damon_new_target(void) 214f23b8eeeSSeongJae Park { 215f23b8eeeSSeongJae Park struct damon_target *t; 216f23b8eeeSSeongJae Park 217f23b8eeeSSeongJae Park t = kmalloc(sizeof(*t), GFP_KERNEL); 218f23b8eeeSSeongJae Park if (!t) 219f23b8eeeSSeongJae Park return NULL; 220f23b8eeeSSeongJae Park 2211971bd63SSeongJae Park t->pid = NULL; 222b9a6ac4eSSeongJae Park t->nr_regions = 0; 223f23b8eeeSSeongJae Park INIT_LIST_HEAD(&t->regions_list); 224f23b8eeeSSeongJae Park 225f23b8eeeSSeongJae Park return t; 226f23b8eeeSSeongJae Park } 227f23b8eeeSSeongJae Park 228f23b8eeeSSeongJae Park void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) 229f23b8eeeSSeongJae Park { 230b9a6ac4eSSeongJae Park list_add_tail(&t->list, &ctx->adaptive_targets); 231f23b8eeeSSeongJae Park } 232f23b8eeeSSeongJae Park 233b5ca3e83SXin Hao bool damon_targets_empty(struct damon_ctx *ctx) 234b5ca3e83SXin Hao { 235b5ca3e83SXin Hao return list_empty(&ctx->adaptive_targets); 236b5ca3e83SXin Hao } 237b5ca3e83SXin Hao 238f23b8eeeSSeongJae Park static void damon_del_target(struct damon_target *t) 239f23b8eeeSSeongJae Park { 240f23b8eeeSSeongJae Park list_del(&t->list); 241f23b8eeeSSeongJae Park } 242f23b8eeeSSeongJae Park 243f23b8eeeSSeongJae Park void damon_free_target(struct damon_target *t) 244f23b8eeeSSeongJae Park { 245f23b8eeeSSeongJae Park struct damon_region *r, *next; 246f23b8eeeSSeongJae Park 247f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 248f23b8eeeSSeongJae Park damon_free_region(r); 249f23b8eeeSSeongJae Park kfree(t); 250f23b8eeeSSeongJae Park } 251f23b8eeeSSeongJae Park 252f23b8eeeSSeongJae Park void damon_destroy_target(struct damon_target *t) 253f23b8eeeSSeongJae Park { 254f23b8eeeSSeongJae Park damon_del_target(t); 255f23b8eeeSSeongJae Park damon_free_target(t); 256f23b8eeeSSeongJae Park } 257f23b8eeeSSeongJae Park 258b9a6ac4eSSeongJae Park unsigned int damon_nr_regions(struct damon_target *t) 259b9a6ac4eSSeongJae Park { 260b9a6ac4eSSeongJae Park return t->nr_regions; 261b9a6ac4eSSeongJae Park } 262b9a6ac4eSSeongJae Park 2632224d848SSeongJae Park struct damon_ctx *damon_new_ctx(void) 2642224d848SSeongJae Park { 2652224d848SSeongJae Park struct damon_ctx *ctx; 2662224d848SSeongJae Park 2672224d848SSeongJae Park ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 2682224d848SSeongJae Park if (!ctx) 2692224d848SSeongJae Park return NULL; 2702224d848SSeongJae Park 2712224d848SSeongJae Park ctx->sample_interval = 5 * 1000; 2722224d848SSeongJae Park ctx->aggr_interval = 100 * 1000; 273f7d911c3SSeongJae Park ctx->ops_update_interval = 60 * 1000 * 1000; 2742224d848SSeongJae Park 2752224d848SSeongJae Park ktime_get_coarse_ts64(&ctx->last_aggregation); 276f7d911c3SSeongJae Park ctx->last_ops_update = ctx->last_aggregation; 2772224d848SSeongJae Park 2782224d848SSeongJae Park mutex_init(&ctx->kdamond_lock); 2792224d848SSeongJae Park 280b9a6ac4eSSeongJae Park ctx->min_nr_regions = 10; 281b9a6ac4eSSeongJae Park ctx->max_nr_regions = 1000; 282b9a6ac4eSSeongJae Park 283b9a6ac4eSSeongJae Park INIT_LIST_HEAD(&ctx->adaptive_targets); 2841f366e42SSeongJae Park INIT_LIST_HEAD(&ctx->schemes); 2852224d848SSeongJae Park 2862224d848SSeongJae Park return ctx; 2872224d848SSeongJae Park } 2882224d848SSeongJae Park 289f23b8eeeSSeongJae Park static void damon_destroy_targets(struct damon_ctx *ctx) 290f23b8eeeSSeongJae Park { 291f23b8eeeSSeongJae Park struct damon_target *t, *next_t; 292f23b8eeeSSeongJae Park 293f7d911c3SSeongJae Park if (ctx->ops.cleanup) { 294f7d911c3SSeongJae Park ctx->ops.cleanup(ctx); 295f23b8eeeSSeongJae Park return; 296f23b8eeeSSeongJae Park } 297f23b8eeeSSeongJae Park 298f23b8eeeSSeongJae Park damon_for_each_target_safe(t, next_t, ctx) 299f23b8eeeSSeongJae Park damon_destroy_target(t); 300f23b8eeeSSeongJae Park } 301f23b8eeeSSeongJae Park 3022224d848SSeongJae Park void damon_destroy_ctx(struct damon_ctx *ctx) 3032224d848SSeongJae Park { 3041f366e42SSeongJae Park struct damos *s, *next_s; 3051f366e42SSeongJae Park 306f23b8eeeSSeongJae Park damon_destroy_targets(ctx); 3071f366e42SSeongJae Park 3081f366e42SSeongJae Park damon_for_each_scheme_safe(s, next_s, ctx) 3091f366e42SSeongJae Park damon_destroy_scheme(s); 3101f366e42SSeongJae Park 3112224d848SSeongJae Park kfree(ctx); 3122224d848SSeongJae Park } 3132224d848SSeongJae Park 3142224d848SSeongJae Park /** 3152224d848SSeongJae Park * damon_set_attrs() - Set attributes for the monitoring. 3162224d848SSeongJae Park * @ctx: monitoring context 3172224d848SSeongJae Park * @sample_int: time interval between samplings 3182224d848SSeongJae Park * @aggr_int: time interval between aggregations 319f7d911c3SSeongJae Park * @ops_upd_int: time interval between monitoring operations updates 320b9a6ac4eSSeongJae Park * @min_nr_reg: minimal number of regions 321b9a6ac4eSSeongJae Park * @max_nr_reg: maximum number of regions 3222224d848SSeongJae Park * 3232224d848SSeongJae Park * This function should not be called while the kdamond is running. 3242224d848SSeongJae Park * Every time interval is in micro-seconds. 3252224d848SSeongJae Park * 3262224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 3272224d848SSeongJae Park */ 3282224d848SSeongJae Park int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int, 329f7d911c3SSeongJae Park unsigned long aggr_int, unsigned long ops_upd_int, 330b9a6ac4eSSeongJae Park unsigned long min_nr_reg, unsigned long max_nr_reg) 3312224d848SSeongJae Park { 3321afaf5cbSSeongJae Park if (min_nr_reg < 3) 333b9a6ac4eSSeongJae Park return -EINVAL; 3341afaf5cbSSeongJae Park if (min_nr_reg > max_nr_reg) 335b9a6ac4eSSeongJae Park return -EINVAL; 336b9a6ac4eSSeongJae Park 3372224d848SSeongJae Park ctx->sample_interval = sample_int; 3382224d848SSeongJae Park ctx->aggr_interval = aggr_int; 339f7d911c3SSeongJae Park ctx->ops_update_interval = ops_upd_int; 340b9a6ac4eSSeongJae Park ctx->min_nr_regions = min_nr_reg; 341b9a6ac4eSSeongJae Park ctx->max_nr_regions = max_nr_reg; 3422224d848SSeongJae Park 3432224d848SSeongJae Park return 0; 3442224d848SSeongJae Park } 3452224d848SSeongJae Park 3464bc05954SSeongJae Park /** 3471f366e42SSeongJae Park * damon_set_schemes() - Set data access monitoring based operation schemes. 3481f366e42SSeongJae Park * @ctx: monitoring context 3491f366e42SSeongJae Park * @schemes: array of the schemes 3501f366e42SSeongJae Park * @nr_schemes: number of entries in @schemes 3511f366e42SSeongJae Park * 3521f366e42SSeongJae Park * This function should not be called while the kdamond of the context is 3531f366e42SSeongJae Park * running. 3541f366e42SSeongJae Park * 3551f366e42SSeongJae Park * Return: 0 if success, or negative error code otherwise. 3561f366e42SSeongJae Park */ 3571f366e42SSeongJae Park int damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes, 3581f366e42SSeongJae Park ssize_t nr_schemes) 3591f366e42SSeongJae Park { 3601f366e42SSeongJae Park struct damos *s, *next; 3611f366e42SSeongJae Park ssize_t i; 3621f366e42SSeongJae Park 3631f366e42SSeongJae Park damon_for_each_scheme_safe(s, next, ctx) 3641f366e42SSeongJae Park damon_destroy_scheme(s); 3651f366e42SSeongJae Park for (i = 0; i < nr_schemes; i++) 3661f366e42SSeongJae Park damon_add_scheme(ctx, schemes[i]); 3671f366e42SSeongJae Park return 0; 3681f366e42SSeongJae Park } 3691f366e42SSeongJae Park 3701f366e42SSeongJae Park /** 3714bc05954SSeongJae Park * damon_nr_running_ctxs() - Return number of currently running contexts. 3724bc05954SSeongJae Park */ 3734bc05954SSeongJae Park int damon_nr_running_ctxs(void) 3744bc05954SSeongJae Park { 3754bc05954SSeongJae Park int nr_ctxs; 3764bc05954SSeongJae Park 3774bc05954SSeongJae Park mutex_lock(&damon_lock); 3784bc05954SSeongJae Park nr_ctxs = nr_running_ctxs; 3794bc05954SSeongJae Park mutex_unlock(&damon_lock); 3804bc05954SSeongJae Park 3814bc05954SSeongJae Park return nr_ctxs; 3824bc05954SSeongJae Park } 3834bc05954SSeongJae Park 384b9a6ac4eSSeongJae Park /* Returns the size upper limit for each monitoring region */ 385b9a6ac4eSSeongJae Park static unsigned long damon_region_sz_limit(struct damon_ctx *ctx) 386b9a6ac4eSSeongJae Park { 387b9a6ac4eSSeongJae Park struct damon_target *t; 388b9a6ac4eSSeongJae Park struct damon_region *r; 389b9a6ac4eSSeongJae Park unsigned long sz = 0; 390b9a6ac4eSSeongJae Park 391b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) { 392b9a6ac4eSSeongJae Park damon_for_each_region(r, t) 393b9a6ac4eSSeongJae Park sz += r->ar.end - r->ar.start; 394b9a6ac4eSSeongJae Park } 395b9a6ac4eSSeongJae Park 396b9a6ac4eSSeongJae Park if (ctx->min_nr_regions) 397b9a6ac4eSSeongJae Park sz /= ctx->min_nr_regions; 398b9a6ac4eSSeongJae Park if (sz < DAMON_MIN_REGION) 399b9a6ac4eSSeongJae Park sz = DAMON_MIN_REGION; 400b9a6ac4eSSeongJae Park 401b9a6ac4eSSeongJae Park return sz; 402b9a6ac4eSSeongJae Park } 403b9a6ac4eSSeongJae Park 4042224d848SSeongJae Park static int kdamond_fn(void *data); 4052224d848SSeongJae Park 4062224d848SSeongJae Park /* 4072224d848SSeongJae Park * __damon_start() - Starts monitoring with given context. 4082224d848SSeongJae Park * @ctx: monitoring context 4092224d848SSeongJae Park * 4102224d848SSeongJae Park * This function should be called while damon_lock is hold. 4112224d848SSeongJae Park * 4122224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4132224d848SSeongJae Park */ 4142224d848SSeongJae Park static int __damon_start(struct damon_ctx *ctx) 4152224d848SSeongJae Park { 4162224d848SSeongJae Park int err = -EBUSY; 4172224d848SSeongJae Park 4182224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 4192224d848SSeongJae Park if (!ctx->kdamond) { 4202224d848SSeongJae Park err = 0; 4212224d848SSeongJae Park ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d", 4222224d848SSeongJae Park nr_running_ctxs); 4232224d848SSeongJae Park if (IS_ERR(ctx->kdamond)) { 4242224d848SSeongJae Park err = PTR_ERR(ctx->kdamond); 4257ec1992bSColin Ian King ctx->kdamond = NULL; 4262224d848SSeongJae Park } 4272224d848SSeongJae Park } 4282224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4292224d848SSeongJae Park 4302224d848SSeongJae Park return err; 4312224d848SSeongJae Park } 4322224d848SSeongJae Park 4332224d848SSeongJae Park /** 4342224d848SSeongJae Park * damon_start() - Starts the monitorings for a given group of contexts. 4352224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to start monitoring 4362224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4372224d848SSeongJae Park * 4382224d848SSeongJae Park * This function starts a group of monitoring threads for a group of monitoring 4392224d848SSeongJae Park * contexts. One thread per each context is created and run in parallel. The 4402224d848SSeongJae Park * caller should handle synchronization between the threads by itself. If a 4412224d848SSeongJae Park * group of threads that created by other 'damon_start()' call is currently 4422224d848SSeongJae Park * running, this function does nothing but returns -EBUSY. 4432224d848SSeongJae Park * 4442224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4452224d848SSeongJae Park */ 4462224d848SSeongJae Park int damon_start(struct damon_ctx **ctxs, int nr_ctxs) 4472224d848SSeongJae Park { 4482224d848SSeongJae Park int i; 4492224d848SSeongJae Park int err = 0; 4502224d848SSeongJae Park 4512224d848SSeongJae Park mutex_lock(&damon_lock); 4522224d848SSeongJae Park if (nr_running_ctxs) { 4532224d848SSeongJae Park mutex_unlock(&damon_lock); 4542224d848SSeongJae Park return -EBUSY; 4552224d848SSeongJae Park } 4562224d848SSeongJae Park 4572224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 4582224d848SSeongJae Park err = __damon_start(ctxs[i]); 4592224d848SSeongJae Park if (err) 4602224d848SSeongJae Park break; 4612224d848SSeongJae Park nr_running_ctxs++; 4622224d848SSeongJae Park } 4632224d848SSeongJae Park mutex_unlock(&damon_lock); 4642224d848SSeongJae Park 4652224d848SSeongJae Park return err; 4662224d848SSeongJae Park } 4672224d848SSeongJae Park 4682224d848SSeongJae Park /* 4692224d848SSeongJae Park * __damon_stop() - Stops monitoring of given context. 4702224d848SSeongJae Park * @ctx: monitoring context 4712224d848SSeongJae Park * 4722224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4732224d848SSeongJae Park */ 4742224d848SSeongJae Park static int __damon_stop(struct damon_ctx *ctx) 4752224d848SSeongJae Park { 4760f91d133SChangbin Du struct task_struct *tsk; 4770f91d133SChangbin Du 4782224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 4790f91d133SChangbin Du tsk = ctx->kdamond; 4800f91d133SChangbin Du if (tsk) { 4810f91d133SChangbin Du get_task_struct(tsk); 4822224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4830f91d133SChangbin Du kthread_stop(tsk); 4840f91d133SChangbin Du put_task_struct(tsk); 4852224d848SSeongJae Park return 0; 4862224d848SSeongJae Park } 4872224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 4882224d848SSeongJae Park 4892224d848SSeongJae Park return -EPERM; 4902224d848SSeongJae Park } 4912224d848SSeongJae Park 4922224d848SSeongJae Park /** 4932224d848SSeongJae Park * damon_stop() - Stops the monitorings for a given group of contexts. 4942224d848SSeongJae Park * @ctxs: an array of the pointers for contexts to stop monitoring 4952224d848SSeongJae Park * @nr_ctxs: size of @ctxs 4962224d848SSeongJae Park * 4972224d848SSeongJae Park * Return: 0 on success, negative error code otherwise. 4982224d848SSeongJae Park */ 4992224d848SSeongJae Park int damon_stop(struct damon_ctx **ctxs, int nr_ctxs) 5002224d848SSeongJae Park { 5012224d848SSeongJae Park int i, err = 0; 5022224d848SSeongJae Park 5032224d848SSeongJae Park for (i = 0; i < nr_ctxs; i++) { 5042224d848SSeongJae Park /* nr_running_ctxs is decremented in kdamond_fn */ 5052224d848SSeongJae Park err = __damon_stop(ctxs[i]); 5062224d848SSeongJae Park if (err) 5072224d848SSeongJae Park return err; 5082224d848SSeongJae Park } 5092224d848SSeongJae Park 5102224d848SSeongJae Park return err; 5112224d848SSeongJae Park } 5122224d848SSeongJae Park 5132224d848SSeongJae Park /* 5142224d848SSeongJae Park * damon_check_reset_time_interval() - Check if a time interval is elapsed. 5152224d848SSeongJae Park * @baseline: the time to check whether the interval has elapsed since 5162224d848SSeongJae Park * @interval: the time interval (microseconds) 5172224d848SSeongJae Park * 5182224d848SSeongJae Park * See whether the given time interval has passed since the given baseline 5192224d848SSeongJae Park * time. If so, it also updates the baseline to current time for next check. 5202224d848SSeongJae Park * 5212224d848SSeongJae Park * Return: true if the time interval has passed, or false otherwise. 5222224d848SSeongJae Park */ 5232224d848SSeongJae Park static bool damon_check_reset_time_interval(struct timespec64 *baseline, 5242224d848SSeongJae Park unsigned long interval) 5252224d848SSeongJae Park { 5262224d848SSeongJae Park struct timespec64 now; 5272224d848SSeongJae Park 5282224d848SSeongJae Park ktime_get_coarse_ts64(&now); 5292224d848SSeongJae Park if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) < 5302224d848SSeongJae Park interval * 1000) 5312224d848SSeongJae Park return false; 5322224d848SSeongJae Park *baseline = now; 5332224d848SSeongJae Park return true; 5342224d848SSeongJae Park } 5352224d848SSeongJae Park 5362224d848SSeongJae Park /* 5372224d848SSeongJae Park * Check whether it is time to flush the aggregated information 5382224d848SSeongJae Park */ 5392224d848SSeongJae Park static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx) 5402224d848SSeongJae Park { 5412224d848SSeongJae Park return damon_check_reset_time_interval(&ctx->last_aggregation, 5422224d848SSeongJae Park ctx->aggr_interval); 5432224d848SSeongJae Park } 5442224d848SSeongJae Park 5452224d848SSeongJae Park /* 546f23b8eeeSSeongJae Park * Reset the aggregated monitoring results ('nr_accesses' of each region). 547f23b8eeeSSeongJae Park */ 548f23b8eeeSSeongJae Park static void kdamond_reset_aggregated(struct damon_ctx *c) 549f23b8eeeSSeongJae Park { 550f23b8eeeSSeongJae Park struct damon_target *t; 55176fd0285SSeongJae Park unsigned int ti = 0; /* target's index */ 552f23b8eeeSSeongJae Park 553f23b8eeeSSeongJae Park damon_for_each_target(t, c) { 554f23b8eeeSSeongJae Park struct damon_region *r; 555f23b8eeeSSeongJae Park 5562fcb9362SSeongJae Park damon_for_each_region(r, t) { 55776fd0285SSeongJae Park trace_damon_aggregated(t, ti, r, damon_nr_regions(t)); 558fda504faSSeongJae Park r->last_nr_accesses = r->nr_accesses; 559f23b8eeeSSeongJae Park r->nr_accesses = 0; 560f23b8eeeSSeongJae Park } 56176fd0285SSeongJae Park ti++; 562f23b8eeeSSeongJae Park } 5632fcb9362SSeongJae Park } 564f23b8eeeSSeongJae Park 5652b8a248dSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 5662b8a248dSSeongJae Park struct damon_target *t, struct damon_region *r, 5672b8a248dSSeongJae Park unsigned long sz_r); 5682b8a248dSSeongJae Park 56938683e00SSeongJae Park static bool __damos_valid_target(struct damon_region *r, struct damos *s) 57038683e00SSeongJae Park { 57138683e00SSeongJae Park unsigned long sz; 57238683e00SSeongJae Park 57338683e00SSeongJae Park sz = r->ar.end - r->ar.start; 57438683e00SSeongJae Park return s->min_sz_region <= sz && sz <= s->max_sz_region && 57538683e00SSeongJae Park s->min_nr_accesses <= r->nr_accesses && 57638683e00SSeongJae Park r->nr_accesses <= s->max_nr_accesses && 57738683e00SSeongJae Park s->min_age_region <= r->age && r->age <= s->max_age_region; 57838683e00SSeongJae Park } 57938683e00SSeongJae Park 58038683e00SSeongJae Park static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, 58138683e00SSeongJae Park struct damon_region *r, struct damos *s) 58238683e00SSeongJae Park { 58338683e00SSeongJae Park bool ret = __damos_valid_target(r, s); 58438683e00SSeongJae Park 585f7d911c3SSeongJae Park if (!ret || !s->quota.esz || !c->ops.get_scheme_score) 58638683e00SSeongJae Park return ret; 58738683e00SSeongJae Park 588f7d911c3SSeongJae Park return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; 58938683e00SSeongJae Park } 59038683e00SSeongJae Park 5911f366e42SSeongJae Park static void damon_do_apply_schemes(struct damon_ctx *c, 5921f366e42SSeongJae Park struct damon_target *t, 5931f366e42SSeongJae Park struct damon_region *r) 5941f366e42SSeongJae Park { 5951f366e42SSeongJae Park struct damos *s; 5961f366e42SSeongJae Park 5971f366e42SSeongJae Park damon_for_each_scheme(s, c) { 5982b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 5992b8a248dSSeongJae Park unsigned long sz = r->ar.end - r->ar.start; 6001cd24303SSeongJae Park struct timespec64 begin, end; 6010e92c2eeSSeongJae Park unsigned long sz_applied = 0; 6022b8a248dSSeongJae Park 603ee801b7dSSeongJae Park if (!s->wmarks.activated) 604ee801b7dSSeongJae Park continue; 605ee801b7dSSeongJae Park 6062b8a248dSSeongJae Park /* Check the quota */ 6071cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 6082b8a248dSSeongJae Park continue; 6092b8a248dSSeongJae Park 61050585192SSeongJae Park /* Skip previously charged regions */ 61150585192SSeongJae Park if (quota->charge_target_from) { 61250585192SSeongJae Park if (t != quota->charge_target_from) 61350585192SSeongJae Park continue; 61450585192SSeongJae Park if (r == damon_last_region(t)) { 61550585192SSeongJae Park quota->charge_target_from = NULL; 61650585192SSeongJae Park quota->charge_addr_from = 0; 61750585192SSeongJae Park continue; 61850585192SSeongJae Park } 61950585192SSeongJae Park if (quota->charge_addr_from && 62050585192SSeongJae Park r->ar.end <= quota->charge_addr_from) 62150585192SSeongJae Park continue; 62250585192SSeongJae Park 62350585192SSeongJae Park if (quota->charge_addr_from && r->ar.start < 62450585192SSeongJae Park quota->charge_addr_from) { 62550585192SSeongJae Park sz = ALIGN_DOWN(quota->charge_addr_from - 62650585192SSeongJae Park r->ar.start, DAMON_MIN_REGION); 62750585192SSeongJae Park if (!sz) { 62850585192SSeongJae Park if (r->ar.end - r->ar.start <= 62950585192SSeongJae Park DAMON_MIN_REGION) 63050585192SSeongJae Park continue; 63150585192SSeongJae Park sz = DAMON_MIN_REGION; 63250585192SSeongJae Park } 63350585192SSeongJae Park damon_split_region_at(c, t, r, sz); 63450585192SSeongJae Park r = damon_next_region(r); 63550585192SSeongJae Park sz = r->ar.end - r->ar.start; 63650585192SSeongJae Park } 63750585192SSeongJae Park quota->charge_target_from = NULL; 63850585192SSeongJae Park quota->charge_addr_from = 0; 63950585192SSeongJae Park } 64050585192SSeongJae Park 64138683e00SSeongJae Park if (!damos_valid_target(c, t, r, s)) 6421f366e42SSeongJae Park continue; 6432b8a248dSSeongJae Park 6442b8a248dSSeongJae Park /* Apply the scheme */ 645f7d911c3SSeongJae Park if (c->ops.apply_scheme) { 6461cd24303SSeongJae Park if (quota->esz && 6471cd24303SSeongJae Park quota->charged_sz + sz > quota->esz) { 6481cd24303SSeongJae Park sz = ALIGN_DOWN(quota->esz - quota->charged_sz, 6492b8a248dSSeongJae Park DAMON_MIN_REGION); 6502b8a248dSSeongJae Park if (!sz) 6512b8a248dSSeongJae Park goto update_stat; 6522b8a248dSSeongJae Park damon_split_region_at(c, t, r, sz); 6532b8a248dSSeongJae Park } 6541cd24303SSeongJae Park ktime_get_coarse_ts64(&begin); 655f7d911c3SSeongJae Park sz_applied = c->ops.apply_scheme(c, t, r, s); 6561cd24303SSeongJae Park ktime_get_coarse_ts64(&end); 6571cd24303SSeongJae Park quota->total_charged_ns += timespec64_to_ns(&end) - 6581cd24303SSeongJae Park timespec64_to_ns(&begin); 6592b8a248dSSeongJae Park quota->charged_sz += sz; 6601cd24303SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) { 66150585192SSeongJae Park quota->charge_target_from = t; 66250585192SSeongJae Park quota->charge_addr_from = r->ar.end + 1; 66350585192SSeongJae Park } 6642b8a248dSSeongJae Park } 6652f0b548cSSeongJae Park if (s->action != DAMOS_STAT) 6661f366e42SSeongJae Park r->age = 0; 6672b8a248dSSeongJae Park 6682b8a248dSSeongJae Park update_stat: 6690e92c2eeSSeongJae Park s->stat.nr_tried++; 6700e92c2eeSSeongJae Park s->stat.sz_tried += sz; 6710e92c2eeSSeongJae Park if (sz_applied) 6720e92c2eeSSeongJae Park s->stat.nr_applied++; 6730e92c2eeSSeongJae Park s->stat.sz_applied += sz_applied; 6741f366e42SSeongJae Park } 6751f366e42SSeongJae Park } 6761f366e42SSeongJae Park 6771cd24303SSeongJae Park /* Shouldn't be called if quota->ms and quota->sz are zero */ 6781cd24303SSeongJae Park static void damos_set_effective_quota(struct damos_quota *quota) 6791cd24303SSeongJae Park { 6801cd24303SSeongJae Park unsigned long throughput; 6811cd24303SSeongJae Park unsigned long esz; 6821cd24303SSeongJae Park 6831cd24303SSeongJae Park if (!quota->ms) { 6841cd24303SSeongJae Park quota->esz = quota->sz; 6851cd24303SSeongJae Park return; 6861cd24303SSeongJae Park } 6871cd24303SSeongJae Park 6881cd24303SSeongJae Park if (quota->total_charged_ns) 6891cd24303SSeongJae Park throughput = quota->total_charged_sz * 1000000 / 6901cd24303SSeongJae Park quota->total_charged_ns; 6911cd24303SSeongJae Park else 6921cd24303SSeongJae Park throughput = PAGE_SIZE * 1024; 6931cd24303SSeongJae Park esz = throughput * quota->ms; 6941cd24303SSeongJae Park 6951cd24303SSeongJae Park if (quota->sz && quota->sz < esz) 6961cd24303SSeongJae Park esz = quota->sz; 6971cd24303SSeongJae Park quota->esz = esz; 6981cd24303SSeongJae Park } 6991cd24303SSeongJae Park 7001f366e42SSeongJae Park static void kdamond_apply_schemes(struct damon_ctx *c) 7011f366e42SSeongJae Park { 7021f366e42SSeongJae Park struct damon_target *t; 7032b8a248dSSeongJae Park struct damon_region *r, *next_r; 7042b8a248dSSeongJae Park struct damos *s; 7052b8a248dSSeongJae Park 7062b8a248dSSeongJae Park damon_for_each_scheme(s, c) { 7072b8a248dSSeongJae Park struct damos_quota *quota = &s->quota; 70838683e00SSeongJae Park unsigned long cumulated_sz; 70938683e00SSeongJae Park unsigned int score, max_score = 0; 7102b8a248dSSeongJae Park 711ee801b7dSSeongJae Park if (!s->wmarks.activated) 712ee801b7dSSeongJae Park continue; 713ee801b7dSSeongJae Park 7141cd24303SSeongJae Park if (!quota->ms && !quota->sz) 7152b8a248dSSeongJae Park continue; 7162b8a248dSSeongJae Park 7172b8a248dSSeongJae Park /* New charge window starts */ 7182b8a248dSSeongJae Park if (time_after_eq(jiffies, quota->charged_from + 7192b8a248dSSeongJae Park msecs_to_jiffies( 7202b8a248dSSeongJae Park quota->reset_interval))) { 7216268eac3SSeongJae Park if (quota->esz && quota->charged_sz >= quota->esz) 7226268eac3SSeongJae Park s->stat.qt_exceeds++; 7231cd24303SSeongJae Park quota->total_charged_sz += quota->charged_sz; 7242b8a248dSSeongJae Park quota->charged_from = jiffies; 7252b8a248dSSeongJae Park quota->charged_sz = 0; 7261cd24303SSeongJae Park damos_set_effective_quota(quota); 7272b8a248dSSeongJae Park } 72838683e00SSeongJae Park 729f7d911c3SSeongJae Park if (!c->ops.get_scheme_score) 73038683e00SSeongJae Park continue; 73138683e00SSeongJae Park 73238683e00SSeongJae Park /* Fill up the score histogram */ 73338683e00SSeongJae Park memset(quota->histogram, 0, sizeof(quota->histogram)); 73438683e00SSeongJae Park damon_for_each_target(t, c) { 73538683e00SSeongJae Park damon_for_each_region(r, t) { 73638683e00SSeongJae Park if (!__damos_valid_target(r, s)) 73738683e00SSeongJae Park continue; 738f7d911c3SSeongJae Park score = c->ops.get_scheme_score( 73938683e00SSeongJae Park c, t, r, s); 74038683e00SSeongJae Park quota->histogram[score] += 74138683e00SSeongJae Park r->ar.end - r->ar.start; 74238683e00SSeongJae Park if (score > max_score) 74338683e00SSeongJae Park max_score = score; 74438683e00SSeongJae Park } 74538683e00SSeongJae Park } 74638683e00SSeongJae Park 74738683e00SSeongJae Park /* Set the min score limit */ 74838683e00SSeongJae Park for (cumulated_sz = 0, score = max_score; ; score--) { 74938683e00SSeongJae Park cumulated_sz += quota->histogram[score]; 75038683e00SSeongJae Park if (cumulated_sz >= quota->esz || !score) 75138683e00SSeongJae Park break; 75238683e00SSeongJae Park } 75338683e00SSeongJae Park quota->min_score = score; 7542b8a248dSSeongJae Park } 7551f366e42SSeongJae Park 7561f366e42SSeongJae Park damon_for_each_target(t, c) { 7572b8a248dSSeongJae Park damon_for_each_region_safe(r, next_r, t) 7581f366e42SSeongJae Park damon_do_apply_schemes(c, t, r); 7591f366e42SSeongJae Park } 7601f366e42SSeongJae Park } 7611f366e42SSeongJae Park 76288f86dcfSSeongJae Park static inline unsigned long sz_damon_region(struct damon_region *r) 76388f86dcfSSeongJae Park { 76488f86dcfSSeongJae Park return r->ar.end - r->ar.start; 76588f86dcfSSeongJae Park } 766b9a6ac4eSSeongJae Park 767b9a6ac4eSSeongJae Park /* 768b9a6ac4eSSeongJae Park * Merge two adjacent regions into one region 769b9a6ac4eSSeongJae Park */ 770b9a6ac4eSSeongJae Park static void damon_merge_two_regions(struct damon_target *t, 771b9a6ac4eSSeongJae Park struct damon_region *l, struct damon_region *r) 772b9a6ac4eSSeongJae Park { 773b9a6ac4eSSeongJae Park unsigned long sz_l = sz_damon_region(l), sz_r = sz_damon_region(r); 774b9a6ac4eSSeongJae Park 775b9a6ac4eSSeongJae Park l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / 776b9a6ac4eSSeongJae Park (sz_l + sz_r); 777fda504faSSeongJae Park l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); 778b9a6ac4eSSeongJae Park l->ar.end = r->ar.end; 779b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 780b9a6ac4eSSeongJae Park } 781b9a6ac4eSSeongJae Park 782b9a6ac4eSSeongJae Park /* 783b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 784b9a6ac4eSSeongJae Park * 785b9a6ac4eSSeongJae Park * t target affected by this merge operation 786b9a6ac4eSSeongJae Park * thres '->nr_accesses' diff threshold for the merge 787b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 788b9a6ac4eSSeongJae Park */ 789b9a6ac4eSSeongJae Park static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, 790b9a6ac4eSSeongJae Park unsigned long sz_limit) 791b9a6ac4eSSeongJae Park { 792b9a6ac4eSSeongJae Park struct damon_region *r, *prev = NULL, *next; 793b9a6ac4eSSeongJae Park 794b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 795d720bbbdSXin Hao if (abs(r->nr_accesses - r->last_nr_accesses) > thres) 796fda504faSSeongJae Park r->age = 0; 797fda504faSSeongJae Park else 798fda504faSSeongJae Park r->age++; 799fda504faSSeongJae Park 800b9a6ac4eSSeongJae Park if (prev && prev->ar.end == r->ar.start && 801d720bbbdSXin Hao abs(prev->nr_accesses - r->nr_accesses) <= thres && 802b9a6ac4eSSeongJae Park sz_damon_region(prev) + sz_damon_region(r) <= sz_limit) 803b9a6ac4eSSeongJae Park damon_merge_two_regions(t, prev, r); 804b9a6ac4eSSeongJae Park else 805b9a6ac4eSSeongJae Park prev = r; 806b9a6ac4eSSeongJae Park } 807b9a6ac4eSSeongJae Park } 808b9a6ac4eSSeongJae Park 809b9a6ac4eSSeongJae Park /* 810b9a6ac4eSSeongJae Park * Merge adjacent regions having similar access frequencies 811b9a6ac4eSSeongJae Park * 812b9a6ac4eSSeongJae Park * threshold '->nr_accesses' diff threshold for the merge 813b9a6ac4eSSeongJae Park * sz_limit size upper limit of each region 814b9a6ac4eSSeongJae Park * 815b9a6ac4eSSeongJae Park * This function merges monitoring target regions which are adjacent and their 816b9a6ac4eSSeongJae Park * access frequencies are similar. This is for minimizing the monitoring 817b9a6ac4eSSeongJae Park * overhead under the dynamically changeable access pattern. If a merge was 818b9a6ac4eSSeongJae Park * unnecessarily made, later 'kdamond_split_regions()' will revert it. 819b9a6ac4eSSeongJae Park */ 820b9a6ac4eSSeongJae Park static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, 821b9a6ac4eSSeongJae Park unsigned long sz_limit) 822b9a6ac4eSSeongJae Park { 823b9a6ac4eSSeongJae Park struct damon_target *t; 824b9a6ac4eSSeongJae Park 825b9a6ac4eSSeongJae Park damon_for_each_target(t, c) 826b9a6ac4eSSeongJae Park damon_merge_regions_of(t, threshold, sz_limit); 827b9a6ac4eSSeongJae Park } 828b9a6ac4eSSeongJae Park 829b9a6ac4eSSeongJae Park /* 830b9a6ac4eSSeongJae Park * Split a region in two 831b9a6ac4eSSeongJae Park * 832b9a6ac4eSSeongJae Park * r the region to be split 833b9a6ac4eSSeongJae Park * sz_r size of the first sub-region that will be made 834b9a6ac4eSSeongJae Park */ 835b9a6ac4eSSeongJae Park static void damon_split_region_at(struct damon_ctx *ctx, 836b9a6ac4eSSeongJae Park struct damon_target *t, struct damon_region *r, 837b9a6ac4eSSeongJae Park unsigned long sz_r) 838b9a6ac4eSSeongJae Park { 839b9a6ac4eSSeongJae Park struct damon_region *new; 840b9a6ac4eSSeongJae Park 841b9a6ac4eSSeongJae Park new = damon_new_region(r->ar.start + sz_r, r->ar.end); 842b9a6ac4eSSeongJae Park if (!new) 843b9a6ac4eSSeongJae Park return; 844b9a6ac4eSSeongJae Park 845b9a6ac4eSSeongJae Park r->ar.end = new->ar.start; 846b9a6ac4eSSeongJae Park 847fda504faSSeongJae Park new->age = r->age; 848fda504faSSeongJae Park new->last_nr_accesses = r->last_nr_accesses; 849fda504faSSeongJae Park 850b9a6ac4eSSeongJae Park damon_insert_region(new, r, damon_next_region(r), t); 851b9a6ac4eSSeongJae Park } 852b9a6ac4eSSeongJae Park 853b9a6ac4eSSeongJae Park /* Split every region in the given target into 'nr_subs' regions */ 854b9a6ac4eSSeongJae Park static void damon_split_regions_of(struct damon_ctx *ctx, 855b9a6ac4eSSeongJae Park struct damon_target *t, int nr_subs) 856b9a6ac4eSSeongJae Park { 857b9a6ac4eSSeongJae Park struct damon_region *r, *next; 858b9a6ac4eSSeongJae Park unsigned long sz_region, sz_sub = 0; 859b9a6ac4eSSeongJae Park int i; 860b9a6ac4eSSeongJae Park 861b9a6ac4eSSeongJae Park damon_for_each_region_safe(r, next, t) { 862b9a6ac4eSSeongJae Park sz_region = r->ar.end - r->ar.start; 863b9a6ac4eSSeongJae Park 864b9a6ac4eSSeongJae Park for (i = 0; i < nr_subs - 1 && 865b9a6ac4eSSeongJae Park sz_region > 2 * DAMON_MIN_REGION; i++) { 866b9a6ac4eSSeongJae Park /* 867b9a6ac4eSSeongJae Park * Randomly select size of left sub-region to be at 868b9a6ac4eSSeongJae Park * least 10 percent and at most 90% of original region 869b9a6ac4eSSeongJae Park */ 870b9a6ac4eSSeongJae Park sz_sub = ALIGN_DOWN(damon_rand(1, 10) * 871b9a6ac4eSSeongJae Park sz_region / 10, DAMON_MIN_REGION); 872b9a6ac4eSSeongJae Park /* Do not allow blank region */ 873b9a6ac4eSSeongJae Park if (sz_sub == 0 || sz_sub >= sz_region) 874b9a6ac4eSSeongJae Park continue; 875b9a6ac4eSSeongJae Park 876b9a6ac4eSSeongJae Park damon_split_region_at(ctx, t, r, sz_sub); 877b9a6ac4eSSeongJae Park sz_region = sz_sub; 878b9a6ac4eSSeongJae Park } 879b9a6ac4eSSeongJae Park } 880b9a6ac4eSSeongJae Park } 881b9a6ac4eSSeongJae Park 882b9a6ac4eSSeongJae Park /* 883b9a6ac4eSSeongJae Park * Split every target region into randomly-sized small regions 884b9a6ac4eSSeongJae Park * 885b9a6ac4eSSeongJae Park * This function splits every target region into random-sized small regions if 886b9a6ac4eSSeongJae Park * current total number of the regions is equal or smaller than half of the 887b9a6ac4eSSeongJae Park * user-specified maximum number of regions. This is for maximizing the 888b9a6ac4eSSeongJae Park * monitoring accuracy under the dynamically changeable access patterns. If a 889b9a6ac4eSSeongJae Park * split was unnecessarily made, later 'kdamond_merge_regions()' will revert 890b9a6ac4eSSeongJae Park * it. 891b9a6ac4eSSeongJae Park */ 892b9a6ac4eSSeongJae Park static void kdamond_split_regions(struct damon_ctx *ctx) 893b9a6ac4eSSeongJae Park { 894b9a6ac4eSSeongJae Park struct damon_target *t; 895b9a6ac4eSSeongJae Park unsigned int nr_regions = 0; 896b9a6ac4eSSeongJae Park static unsigned int last_nr_regions; 897b9a6ac4eSSeongJae Park int nr_subregions = 2; 898b9a6ac4eSSeongJae Park 899b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 900b9a6ac4eSSeongJae Park nr_regions += damon_nr_regions(t); 901b9a6ac4eSSeongJae Park 902b9a6ac4eSSeongJae Park if (nr_regions > ctx->max_nr_regions / 2) 903b9a6ac4eSSeongJae Park return; 904b9a6ac4eSSeongJae Park 905b9a6ac4eSSeongJae Park /* Maybe the middle of the region has different access frequency */ 906b9a6ac4eSSeongJae Park if (last_nr_regions == nr_regions && 907b9a6ac4eSSeongJae Park nr_regions < ctx->max_nr_regions / 3) 908b9a6ac4eSSeongJae Park nr_subregions = 3; 909b9a6ac4eSSeongJae Park 910b9a6ac4eSSeongJae Park damon_for_each_target(t, ctx) 911b9a6ac4eSSeongJae Park damon_split_regions_of(ctx, t, nr_subregions); 912b9a6ac4eSSeongJae Park 913b9a6ac4eSSeongJae Park last_nr_regions = nr_regions; 914b9a6ac4eSSeongJae Park } 915b9a6ac4eSSeongJae Park 916f23b8eeeSSeongJae Park /* 917f7d911c3SSeongJae Park * Check whether it is time to check and apply the operations-related data 918f7d911c3SSeongJae Park * structures. 9192224d848SSeongJae Park * 9202224d848SSeongJae Park * Returns true if it is. 9212224d848SSeongJae Park */ 922f7d911c3SSeongJae Park static bool kdamond_need_update_operations(struct damon_ctx *ctx) 9232224d848SSeongJae Park { 924f7d911c3SSeongJae Park return damon_check_reset_time_interval(&ctx->last_ops_update, 925f7d911c3SSeongJae Park ctx->ops_update_interval); 9262224d848SSeongJae Park } 9272224d848SSeongJae Park 9282224d848SSeongJae Park /* 9292224d848SSeongJae Park * Check whether current monitoring should be stopped 9302224d848SSeongJae Park * 9312224d848SSeongJae Park * The monitoring is stopped when either the user requested to stop, or all 9322224d848SSeongJae Park * monitoring targets are invalid. 9332224d848SSeongJae Park * 9342224d848SSeongJae Park * Returns true if need to stop current monitoring. 9352224d848SSeongJae Park */ 9362224d848SSeongJae Park static bool kdamond_need_stop(struct damon_ctx *ctx) 9372224d848SSeongJae Park { 938f23b8eeeSSeongJae Park struct damon_target *t; 9392224d848SSeongJae Park 9400f91d133SChangbin Du if (kthread_should_stop()) 9412224d848SSeongJae Park return true; 9422224d848SSeongJae Park 943f7d911c3SSeongJae Park if (!ctx->ops.target_valid) 9442224d848SSeongJae Park return false; 9452224d848SSeongJae Park 946f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 947f7d911c3SSeongJae Park if (ctx->ops.target_valid(t)) 948f23b8eeeSSeongJae Park return false; 949f23b8eeeSSeongJae Park } 950f23b8eeeSSeongJae Park 951f23b8eeeSSeongJae Park return true; 9522224d848SSeongJae Park } 9532224d848SSeongJae Park 954ee801b7dSSeongJae Park static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric) 955ee801b7dSSeongJae Park { 956ee801b7dSSeongJae Park struct sysinfo i; 957ee801b7dSSeongJae Park 958ee801b7dSSeongJae Park switch (metric) { 959ee801b7dSSeongJae Park case DAMOS_WMARK_FREE_MEM_RATE: 960ee801b7dSSeongJae Park si_meminfo(&i); 961ee801b7dSSeongJae Park return i.freeram * 1000 / i.totalram; 962ee801b7dSSeongJae Park default: 963ee801b7dSSeongJae Park break; 964ee801b7dSSeongJae Park } 965ee801b7dSSeongJae Park return -EINVAL; 966ee801b7dSSeongJae Park } 967ee801b7dSSeongJae Park 968ee801b7dSSeongJae Park /* 969ee801b7dSSeongJae Park * Returns zero if the scheme is active. Else, returns time to wait for next 970ee801b7dSSeongJae Park * watermark check in micro-seconds. 971ee801b7dSSeongJae Park */ 972ee801b7dSSeongJae Park static unsigned long damos_wmark_wait_us(struct damos *scheme) 973ee801b7dSSeongJae Park { 974ee801b7dSSeongJae Park unsigned long metric; 975ee801b7dSSeongJae Park 976ee801b7dSSeongJae Park if (scheme->wmarks.metric == DAMOS_WMARK_NONE) 977ee801b7dSSeongJae Park return 0; 978ee801b7dSSeongJae Park 979ee801b7dSSeongJae Park metric = damos_wmark_metric_value(scheme->wmarks.metric); 980ee801b7dSSeongJae Park /* higher than high watermark or lower than low watermark */ 981ee801b7dSSeongJae Park if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) { 982ee801b7dSSeongJae Park if (scheme->wmarks.activated) 98301078655SColin Ian King pr_debug("deactivate a scheme (%d) for %s wmark\n", 984ee801b7dSSeongJae Park scheme->action, 985ee801b7dSSeongJae Park metric > scheme->wmarks.high ? 986ee801b7dSSeongJae Park "high" : "low"); 987ee801b7dSSeongJae Park scheme->wmarks.activated = false; 988ee801b7dSSeongJae Park return scheme->wmarks.interval; 989ee801b7dSSeongJae Park } 990ee801b7dSSeongJae Park 991ee801b7dSSeongJae Park /* inactive and higher than middle watermark */ 992ee801b7dSSeongJae Park if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) && 993ee801b7dSSeongJae Park !scheme->wmarks.activated) 994ee801b7dSSeongJae Park return scheme->wmarks.interval; 995ee801b7dSSeongJae Park 996ee801b7dSSeongJae Park if (!scheme->wmarks.activated) 997ee801b7dSSeongJae Park pr_debug("activate a scheme (%d)\n", scheme->action); 998ee801b7dSSeongJae Park scheme->wmarks.activated = true; 999ee801b7dSSeongJae Park return 0; 1000ee801b7dSSeongJae Park } 1001ee801b7dSSeongJae Park 1002ee801b7dSSeongJae Park static void kdamond_usleep(unsigned long usecs) 1003ee801b7dSSeongJae Park { 10044de46a30SSeongJae Park /* See Documentation/timers/timers-howto.rst for the thresholds */ 10054de46a30SSeongJae Park if (usecs > 20 * USEC_PER_MSEC) 100670e92748SSeongJae Park schedule_timeout_idle(usecs_to_jiffies(usecs)); 1007ee801b7dSSeongJae Park else 100870e92748SSeongJae Park usleep_idle_range(usecs, usecs + 1); 1009ee801b7dSSeongJae Park } 1010ee801b7dSSeongJae Park 1011ee801b7dSSeongJae Park /* Returns negative error code if it's not activated but should return */ 1012ee801b7dSSeongJae Park static int kdamond_wait_activation(struct damon_ctx *ctx) 1013ee801b7dSSeongJae Park { 1014ee801b7dSSeongJae Park struct damos *s; 1015ee801b7dSSeongJae Park unsigned long wait_time; 1016ee801b7dSSeongJae Park unsigned long min_wait_time = 0; 1017ee801b7dSSeongJae Park 1018ee801b7dSSeongJae Park while (!kdamond_need_stop(ctx)) { 1019ee801b7dSSeongJae Park damon_for_each_scheme(s, ctx) { 1020ee801b7dSSeongJae Park wait_time = damos_wmark_wait_us(s); 1021ee801b7dSSeongJae Park if (!min_wait_time || wait_time < min_wait_time) 1022ee801b7dSSeongJae Park min_wait_time = wait_time; 1023ee801b7dSSeongJae Park } 1024ee801b7dSSeongJae Park if (!min_wait_time) 1025ee801b7dSSeongJae Park return 0; 1026ee801b7dSSeongJae Park 1027ee801b7dSSeongJae Park kdamond_usleep(min_wait_time); 1028ee801b7dSSeongJae Park } 1029ee801b7dSSeongJae Park return -EBUSY; 1030ee801b7dSSeongJae Park } 1031ee801b7dSSeongJae Park 10322224d848SSeongJae Park /* 10332224d848SSeongJae Park * The monitoring daemon that runs as a kernel thread 10342224d848SSeongJae Park */ 10352224d848SSeongJae Park static int kdamond_fn(void *data) 10362224d848SSeongJae Park { 10372224d848SSeongJae Park struct damon_ctx *ctx = (struct damon_ctx *)data; 1038f23b8eeeSSeongJae Park struct damon_target *t; 1039f23b8eeeSSeongJae Park struct damon_region *r, *next; 1040b9a6ac4eSSeongJae Park unsigned int max_nr_accesses = 0; 1041b9a6ac4eSSeongJae Park unsigned long sz_limit = 0; 10420f91d133SChangbin Du bool done = false; 10432224d848SSeongJae Park 104442e4cef5SChangbin Du pr_debug("kdamond (%d) starts\n", current->pid); 10452224d848SSeongJae Park 1046f7d911c3SSeongJae Park if (ctx->ops.init) 1047f7d911c3SSeongJae Park ctx->ops.init(ctx); 10482224d848SSeongJae Park if (ctx->callback.before_start && ctx->callback.before_start(ctx)) 10490f91d133SChangbin Du done = true; 10502224d848SSeongJae Park 1051b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 1052b9a6ac4eSSeongJae Park 10530f91d133SChangbin Du while (!kdamond_need_stop(ctx) && !done) { 1054ee801b7dSSeongJae Park if (kdamond_wait_activation(ctx)) 1055ee801b7dSSeongJae Park continue; 1056ee801b7dSSeongJae Park 1057f7d911c3SSeongJae Park if (ctx->ops.prepare_access_checks) 1058f7d911c3SSeongJae Park ctx->ops.prepare_access_checks(ctx); 10592224d848SSeongJae Park if (ctx->callback.after_sampling && 10602224d848SSeongJae Park ctx->callback.after_sampling(ctx)) 10610f91d133SChangbin Du done = true; 10622224d848SSeongJae Park 106370e92748SSeongJae Park kdamond_usleep(ctx->sample_interval); 10642224d848SSeongJae Park 1065f7d911c3SSeongJae Park if (ctx->ops.check_accesses) 1066f7d911c3SSeongJae Park max_nr_accesses = ctx->ops.check_accesses(ctx); 10672224d848SSeongJae Park 10682224d848SSeongJae Park if (kdamond_aggregate_interval_passed(ctx)) { 1069b9a6ac4eSSeongJae Park kdamond_merge_regions(ctx, 1070b9a6ac4eSSeongJae Park max_nr_accesses / 10, 1071b9a6ac4eSSeongJae Park sz_limit); 10722224d848SSeongJae Park if (ctx->callback.after_aggregation && 10732224d848SSeongJae Park ctx->callback.after_aggregation(ctx)) 10740f91d133SChangbin Du done = true; 10751f366e42SSeongJae Park kdamond_apply_schemes(ctx); 1076f23b8eeeSSeongJae Park kdamond_reset_aggregated(ctx); 1077b9a6ac4eSSeongJae Park kdamond_split_regions(ctx); 1078f7d911c3SSeongJae Park if (ctx->ops.reset_aggregated) 1079f7d911c3SSeongJae Park ctx->ops.reset_aggregated(ctx); 10802224d848SSeongJae Park } 10812224d848SSeongJae Park 1082f7d911c3SSeongJae Park if (kdamond_need_update_operations(ctx)) { 1083f7d911c3SSeongJae Park if (ctx->ops.update) 1084f7d911c3SSeongJae Park ctx->ops.update(ctx); 1085b9a6ac4eSSeongJae Park sz_limit = damon_region_sz_limit(ctx); 10862224d848SSeongJae Park } 10872224d848SSeongJae Park } 1088f23b8eeeSSeongJae Park damon_for_each_target(t, ctx) { 1089f23b8eeeSSeongJae Park damon_for_each_region_safe(r, next, t) 1090b9a6ac4eSSeongJae Park damon_destroy_region(r, t); 1091f23b8eeeSSeongJae Park } 10922224d848SSeongJae Park 10930f91d133SChangbin Du if (ctx->callback.before_terminate) 10940f91d133SChangbin Du ctx->callback.before_terminate(ctx); 1095f7d911c3SSeongJae Park if (ctx->ops.cleanup) 1096f7d911c3SSeongJae Park ctx->ops.cleanup(ctx); 10972224d848SSeongJae Park 109842e4cef5SChangbin Du pr_debug("kdamond (%d) finishes\n", current->pid); 10992224d848SSeongJae Park mutex_lock(&ctx->kdamond_lock); 11002224d848SSeongJae Park ctx->kdamond = NULL; 11012224d848SSeongJae Park mutex_unlock(&ctx->kdamond_lock); 11022224d848SSeongJae Park 11032224d848SSeongJae Park mutex_lock(&damon_lock); 11042224d848SSeongJae Park nr_running_ctxs--; 11052224d848SSeongJae Park mutex_unlock(&damon_lock); 11062224d848SSeongJae Park 11075f7fe2b9SChangbin Du return 0; 11082224d848SSeongJae Park } 110917ccae8bSSeongJae Park 111017ccae8bSSeongJae Park #include "core-test.h" 1111