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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * DAMON-based LRU-lists Sorting
4 *
5 * Author: SeongJae Park <sj@kernel.org>
6 */
7
8#define pr_fmt(fmt) "damon-lru-sort: " fmt
9
10#include <linux/damon.h>
11#include <linux/kstrtox.h>
12#include <linux/module.h>
13
14#include "modules-common.h"
15
16#ifdef MODULE_PARAM_PREFIX
17#undef MODULE_PARAM_PREFIX
18#endif
19#define MODULE_PARAM_PREFIX "damon_lru_sort."
20
21/*
22 * Enable or disable DAMON_LRU_SORT.
23 *
24 * You can enable DAMON_LRU_SORT by setting the value of this parameter as
25 * ``Y``. Setting it as ``N`` disables DAMON_LRU_SORT. Note that
26 * DAMON_LRU_SORT could do no real monitoring and LRU-lists sorting due to the
27 * watermarks-based activation condition. Refer to below descriptions for the
28 * watermarks parameter for this.
29 */
30static bool enabled __read_mostly;
31
32/*
33 * Make DAMON_LRU_SORT reads the input parameters again, except ``enabled``.
34 *
35 * Input parameters that updated while DAMON_LRU_SORT is running are not
36 * applied by default. Once this parameter is set as ``Y``, DAMON_LRU_SORT
37 * reads values of parametrs except ``enabled`` again. Once the re-reading is
38 * done, this parameter is set as ``N``. If invalid parameters are found while
39 * the re-reading, DAMON_LRU_SORT will be disabled.
40 */
41static bool commit_inputs __read_mostly;
42module_param(commit_inputs, bool, 0600);
43
44/*
45 * Access frequency threshold for hot memory regions identification in permil.
46 *
47 * If a memory region is accessed in frequency of this or higher,
48 * DAMON_LRU_SORT identifies the region as hot, and mark it as accessed on the
49 * LRU list, so that it could not be reclaimed under memory pressure. 50% by
50 * default.
51 */
52static unsigned long hot_thres_access_freq = 500;
53module_param(hot_thres_access_freq, ulong, 0600);
54
55/*
56 * Time threshold for cold memory regions identification in microseconds.
57 *
58 * If a memory region is not accessed for this or longer time, DAMON_LRU_SORT
59 * identifies the region as cold, and mark it as unaccessed on the LRU list, so
60 * that it could be reclaimed first under memory pressure. 120 seconds by
61 * default.
62 */
63static unsigned long cold_min_age __read_mostly = 120000000;
64module_param(cold_min_age, ulong, 0600);
65
66static struct damos_quota damon_lru_sort_quota = {
67 /* Use up to 10 ms per 1 sec, by default */
68 .ms = 10,
69 .sz = 0,
70 .reset_interval = 1000,
71 /* Within the quota, mark hotter regions accessed first. */
72 .weight_sz = 0,
73 .weight_nr_accesses = 1,
74 .weight_age = 0,
75};
76DEFINE_DAMON_MODULES_DAMOS_TIME_QUOTA(damon_lru_sort_quota);
77
78static struct damos_watermarks damon_lru_sort_wmarks = {
79 .metric = DAMOS_WMARK_FREE_MEM_RATE,
80 .interval = 5000000, /* 5 seconds */
81 .high = 200, /* 20 percent */
82 .mid = 150, /* 15 percent */
83 .low = 50, /* 5 percent */
84};
85DEFINE_DAMON_MODULES_WMARKS_PARAMS(damon_lru_sort_wmarks);
86
87static struct damon_attrs damon_lru_sort_mon_attrs = {
88 .sample_interval = 5000, /* 5 ms */
89 .aggr_interval = 100000, /* 100 ms */
90 .ops_update_interval = 0,
91 .min_nr_regions = 10,
92 .max_nr_regions = 1000,
93};
94DEFINE_DAMON_MODULES_MON_ATTRS_PARAMS(damon_lru_sort_mon_attrs);
95
96/*
97 * Start of the target memory region in physical address.
98 *
99 * The start physical address of memory region that DAMON_LRU_SORT will do work
100 * against. By default, biggest System RAM is used as the region.
101 */
102static unsigned long monitor_region_start __read_mostly;
103module_param(monitor_region_start, ulong, 0600);
104
105/*
106 * End of the target memory region in physical address.
107 *
108 * The end physical address of memory region that DAMON_LRU_SORT will do work
109 * against. By default, biggest System RAM is used as the region.
110 */
111static unsigned long monitor_region_end __read_mostly;
112module_param(monitor_region_end, ulong, 0600);
113
114/*
115 * PID of the DAMON thread
116 *
117 * If DAMON_LRU_SORT is enabled, this becomes the PID of the worker thread.
118 * Else, -1.
119 */
120static int kdamond_pid __read_mostly = -1;
121module_param(kdamond_pid, int, 0400);
122
123static struct damos_stat damon_lru_sort_hot_stat;
124DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_hot_stat,
125 lru_sort_tried_hot_regions, lru_sorted_hot_regions,
126 hot_quota_exceeds);
127
128static struct damos_stat damon_lru_sort_cold_stat;
129DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_cold_stat,
130 lru_sort_tried_cold_regions, lru_sorted_cold_regions,
131 cold_quota_exceeds);
132
133static struct damos_access_pattern damon_lru_sort_stub_pattern = {
134 /* Find regions having PAGE_SIZE or larger size */
135 .min_sz_region = PAGE_SIZE,
136 .max_sz_region = ULONG_MAX,
137 /* no matter its access frequency */
138 .min_nr_accesses = 0,
139 .max_nr_accesses = UINT_MAX,
140 /* no matter its age */
141 .min_age_region = 0,
142 .max_age_region = UINT_MAX,
143};
144
145static struct damon_ctx *ctx;
146static struct damon_target *target;
147
148static struct damos *damon_lru_sort_new_scheme(
149 struct damos_access_pattern *pattern, enum damos_action action)
150{
151 struct damos_quota quota = damon_lru_sort_quota;
152
153 /* Use half of total quota for hot/cold pages sorting */
154 quota.ms = quota.ms / 2;
155
156 return damon_new_scheme(
157 /* find the pattern, and */
158 pattern,
159 /* (de)prioritize on LRU-lists */
160 action,
161 /* under the quota. */
162 "a,
163 /* (De)activate this according to the watermarks. */
164 &damon_lru_sort_wmarks);
165}
166
167/* Create a DAMON-based operation scheme for hot memory regions */
168static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
169{
170 struct damos_access_pattern pattern = damon_lru_sort_stub_pattern;
171
172 pattern.min_nr_accesses = hot_thres;
173 return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_PRIO);
174}
175
176/* Create a DAMON-based operation scheme for cold memory regions */
177static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres)
178{
179 struct damos_access_pattern pattern = damon_lru_sort_stub_pattern;
180
181 pattern.max_nr_accesses = 0;
182 pattern.min_age_region = cold_thres;
183 return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO);
184}
185
186static int damon_lru_sort_apply_parameters(void)
187{
188 struct damos *scheme;
189 unsigned int hot_thres, cold_thres;
190 int err = 0;
191
192 err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
193 if (err)
194 return err;
195
196 /* aggr_interval / sample_interval is the maximum nr_accesses */
197 hot_thres = damon_lru_sort_mon_attrs.aggr_interval /
198 damon_lru_sort_mon_attrs.sample_interval *
199 hot_thres_access_freq / 1000;
200 scheme = damon_lru_sort_new_hot_scheme(hot_thres);
201 if (!scheme)
202 return -ENOMEM;
203 damon_set_schemes(ctx, &scheme, 1);
204
205 cold_thres = cold_min_age / damon_lru_sort_mon_attrs.aggr_interval;
206 scheme = damon_lru_sort_new_cold_scheme(cold_thres);
207 if (!scheme)
208 return -ENOMEM;
209 damon_add_scheme(ctx, scheme);
210
211 return damon_set_region_biggest_system_ram_default(target,
212 &monitor_region_start,
213 &monitor_region_end);
214}
215
216static int damon_lru_sort_turn(bool on)
217{
218 int err;
219
220 if (!on) {
221 err = damon_stop(&ctx, 1);
222 if (!err)
223 kdamond_pid = -1;
224 return err;
225 }
226
227 err = damon_lru_sort_apply_parameters();
228 if (err)
229 return err;
230
231 err = damon_start(&ctx, 1, true);
232 if (err)
233 return err;
234 kdamond_pid = ctx->kdamond->pid;
235 return 0;
236}
237
238static int damon_lru_sort_enabled_store(const char *val,
239 const struct kernel_param *kp)
240{
241 bool is_enabled = enabled;
242 bool enable;
243 int err;
244
245 err = kstrtobool(val, &enable);
246 if (err)
247 return err;
248
249 if (is_enabled == enable)
250 return 0;
251
252 /* Called before init function. The function will handle this. */
253 if (!ctx)
254 goto set_param_out;
255
256 err = damon_lru_sort_turn(enable);
257 if (err)
258 return err;
259
260set_param_out:
261 enabled = enable;
262 return err;
263}
264
265static const struct kernel_param_ops enabled_param_ops = {
266 .set = damon_lru_sort_enabled_store,
267 .get = param_get_bool,
268};
269
270module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
271MODULE_PARM_DESC(enabled,
272 "Enable or disable DAMON_LRU_SORT (default: disabled)");
273
274static int damon_lru_sort_handle_commit_inputs(void)
275{
276 int err;
277
278 if (!commit_inputs)
279 return 0;
280
281 err = damon_lru_sort_apply_parameters();
282 commit_inputs = false;
283 return err;
284}
285
286static int damon_lru_sort_after_aggregation(struct damon_ctx *c)
287{
288 struct damos *s;
289
290 /* update the stats parameter */
291 damon_for_each_scheme(s, c) {
292 if (s->action == DAMOS_LRU_PRIO)
293 damon_lru_sort_hot_stat = s->stat;
294 else if (s->action == DAMOS_LRU_DEPRIO)
295 damon_lru_sort_cold_stat = s->stat;
296 }
297
298 return damon_lru_sort_handle_commit_inputs();
299}
300
301static int damon_lru_sort_after_wmarks_check(struct damon_ctx *c)
302{
303 return damon_lru_sort_handle_commit_inputs();
304}
305
306static int __init damon_lru_sort_init(void)
307{
308 int err = damon_modules_new_paddr_ctx_target(&ctx, &target);
309
310 if (err)
311 return err;
312
313 ctx->callback.after_wmarks_check = damon_lru_sort_after_wmarks_check;
314 ctx->callback.after_aggregation = damon_lru_sort_after_aggregation;
315
316 /* 'enabled' has set before this function, probably via command line */
317 if (enabled)
318 err = damon_lru_sort_turn(true);
319
320 return err;
321}
322
323module_init(damon_lru_sort_init);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * DAMON-based LRU-lists Sorting
4 *
5 * Author: SeongJae Park <sj@kernel.org>
6 */
7
8#define pr_fmt(fmt) "damon-lru-sort: " fmt
9
10#include <linux/damon.h>
11#include <linux/kstrtox.h>
12#include <linux/module.h>
13
14#include "modules-common.h"
15
16#ifdef MODULE_PARAM_PREFIX
17#undef MODULE_PARAM_PREFIX
18#endif
19#define MODULE_PARAM_PREFIX "damon_lru_sort."
20
21/*
22 * Enable or disable DAMON_LRU_SORT.
23 *
24 * You can enable DAMON_LRU_SORT by setting the value of this parameter as
25 * ``Y``. Setting it as ``N`` disables DAMON_LRU_SORT. Note that
26 * DAMON_LRU_SORT could do no real monitoring and LRU-lists sorting due to the
27 * watermarks-based activation condition. Refer to below descriptions for the
28 * watermarks parameter for this.
29 */
30static bool enabled __read_mostly;
31
32/*
33 * Make DAMON_LRU_SORT reads the input parameters again, except ``enabled``.
34 *
35 * Input parameters that updated while DAMON_LRU_SORT is running are not
36 * applied by default. Once this parameter is set as ``Y``, DAMON_LRU_SORT
37 * reads values of parametrs except ``enabled`` again. Once the re-reading is
38 * done, this parameter is set as ``N``. If invalid parameters are found while
39 * the re-reading, DAMON_LRU_SORT will be disabled.
40 */
41static bool commit_inputs __read_mostly;
42module_param(commit_inputs, bool, 0600);
43
44/*
45 * Access frequency threshold for hot memory regions identification in permil.
46 *
47 * If a memory region is accessed in frequency of this or higher,
48 * DAMON_LRU_SORT identifies the region as hot, and mark it as accessed on the
49 * LRU list, so that it could not be reclaimed under memory pressure. 50% by
50 * default.
51 */
52static unsigned long hot_thres_access_freq = 500;
53module_param(hot_thres_access_freq, ulong, 0600);
54
55/*
56 * Time threshold for cold memory regions identification in microseconds.
57 *
58 * If a memory region is not accessed for this or longer time, DAMON_LRU_SORT
59 * identifies the region as cold, and mark it as unaccessed on the LRU list, so
60 * that it could be reclaimed first under memory pressure. 120 seconds by
61 * default.
62 */
63static unsigned long cold_min_age __read_mostly = 120000000;
64module_param(cold_min_age, ulong, 0600);
65
66static struct damos_quota damon_lru_sort_quota = {
67 /* Use up to 10 ms per 1 sec, by default */
68 .ms = 10,
69 .sz = 0,
70 .reset_interval = 1000,
71 /* Within the quota, mark hotter regions accessed first. */
72 .weight_sz = 0,
73 .weight_nr_accesses = 1,
74 .weight_age = 0,
75};
76DEFINE_DAMON_MODULES_DAMOS_TIME_QUOTA(damon_lru_sort_quota);
77
78static struct damos_watermarks damon_lru_sort_wmarks = {
79 .metric = DAMOS_WMARK_FREE_MEM_RATE,
80 .interval = 5000000, /* 5 seconds */
81 .high = 200, /* 20 percent */
82 .mid = 150, /* 15 percent */
83 .low = 50, /* 5 percent */
84};
85DEFINE_DAMON_MODULES_WMARKS_PARAMS(damon_lru_sort_wmarks);
86
87static struct damon_attrs damon_lru_sort_mon_attrs = {
88 .sample_interval = 5000, /* 5 ms */
89 .aggr_interval = 100000, /* 100 ms */
90 .ops_update_interval = 0,
91 .min_nr_regions = 10,
92 .max_nr_regions = 1000,
93};
94DEFINE_DAMON_MODULES_MON_ATTRS_PARAMS(damon_lru_sort_mon_attrs);
95
96/*
97 * Start of the target memory region in physical address.
98 *
99 * The start physical address of memory region that DAMON_LRU_SORT will do work
100 * against. By default, biggest System RAM is used as the region.
101 */
102static unsigned long monitor_region_start __read_mostly;
103module_param(monitor_region_start, ulong, 0600);
104
105/*
106 * End of the target memory region in physical address.
107 *
108 * The end physical address of memory region that DAMON_LRU_SORT will do work
109 * against. By default, biggest System RAM is used as the region.
110 */
111static unsigned long monitor_region_end __read_mostly;
112module_param(monitor_region_end, ulong, 0600);
113
114/*
115 * PID of the DAMON thread
116 *
117 * If DAMON_LRU_SORT is enabled, this becomes the PID of the worker thread.
118 * Else, -1.
119 */
120static int kdamond_pid __read_mostly = -1;
121module_param(kdamond_pid, int, 0400);
122
123static struct damos_stat damon_lru_sort_hot_stat;
124DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_hot_stat,
125 lru_sort_tried_hot_regions, lru_sorted_hot_regions,
126 hot_quota_exceeds);
127
128static struct damos_stat damon_lru_sort_cold_stat;
129DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_cold_stat,
130 lru_sort_tried_cold_regions, lru_sorted_cold_regions,
131 cold_quota_exceeds);
132
133static struct damos_access_pattern damon_lru_sort_stub_pattern = {
134 /* Find regions having PAGE_SIZE or larger size */
135 .min_sz_region = PAGE_SIZE,
136 .max_sz_region = ULONG_MAX,
137 /* no matter its access frequency */
138 .min_nr_accesses = 0,
139 .max_nr_accesses = UINT_MAX,
140 /* no matter its age */
141 .min_age_region = 0,
142 .max_age_region = UINT_MAX,
143};
144
145static struct damon_ctx *ctx;
146static struct damon_target *target;
147
148static struct damos *damon_lru_sort_new_scheme(
149 struct damos_access_pattern *pattern, enum damos_action action)
150{
151 struct damos_quota quota = damon_lru_sort_quota;
152
153 /* Use half of total quota for hot/cold pages sorting */
154 quota.ms = quota.ms / 2;
155
156 return damon_new_scheme(
157 /* find the pattern, and */
158 pattern,
159 /* (de)prioritize on LRU-lists */
160 action,
161 /* for each aggregation interval */
162 0,
163 /* under the quota. */
164 "a,
165 /* (De)activate this according to the watermarks. */
166 &damon_lru_sort_wmarks,
167 NUMA_NO_NODE);
168}
169
170/* Create a DAMON-based operation scheme for hot memory regions */
171static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
172{
173 struct damos_access_pattern pattern = damon_lru_sort_stub_pattern;
174
175 pattern.min_nr_accesses = hot_thres;
176 return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_PRIO);
177}
178
179/* Create a DAMON-based operation scheme for cold memory regions */
180static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres)
181{
182 struct damos_access_pattern pattern = damon_lru_sort_stub_pattern;
183
184 pattern.max_nr_accesses = 0;
185 pattern.min_age_region = cold_thres;
186 return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO);
187}
188
189static int damon_lru_sort_apply_parameters(void)
190{
191 struct damon_ctx *param_ctx;
192 struct damon_target *param_target;
193 struct damos *hot_scheme, *cold_scheme;
194 unsigned int hot_thres, cold_thres;
195 int err;
196
197 err = damon_modules_new_paddr_ctx_target(¶m_ctx, ¶m_target);
198 if (err)
199 return err;
200
201 err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
202 if (err)
203 goto out;
204
205 err = -ENOMEM;
206 hot_thres = damon_max_nr_accesses(&damon_lru_sort_mon_attrs) *
207 hot_thres_access_freq / 1000;
208 hot_scheme = damon_lru_sort_new_hot_scheme(hot_thres);
209 if (!hot_scheme)
210 goto out;
211
212 cold_thres = cold_min_age / damon_lru_sort_mon_attrs.aggr_interval;
213 cold_scheme = damon_lru_sort_new_cold_scheme(cold_thres);
214 if (!cold_scheme) {
215 damon_destroy_scheme(hot_scheme);
216 goto out;
217 }
218
219 damon_set_schemes(param_ctx, &hot_scheme, 1);
220 damon_add_scheme(param_ctx, cold_scheme);
221
222 err = damon_set_region_biggest_system_ram_default(param_target,
223 &monitor_region_start,
224 &monitor_region_end);
225 if (err)
226 goto out;
227 err = damon_commit_ctx(ctx, param_ctx);
228out:
229 damon_destroy_ctx(param_ctx);
230 return err;
231}
232
233static int damon_lru_sort_turn(bool on)
234{
235 int err;
236
237 if (!on) {
238 err = damon_stop(&ctx, 1);
239 if (!err)
240 kdamond_pid = -1;
241 return err;
242 }
243
244 err = damon_lru_sort_apply_parameters();
245 if (err)
246 return err;
247
248 err = damon_start(&ctx, 1, true);
249 if (err)
250 return err;
251 kdamond_pid = ctx->kdamond->pid;
252 return 0;
253}
254
255static int damon_lru_sort_enabled_store(const char *val,
256 const struct kernel_param *kp)
257{
258 bool is_enabled = enabled;
259 bool enable;
260 int err;
261
262 err = kstrtobool(val, &enable);
263 if (err)
264 return err;
265
266 if (is_enabled == enable)
267 return 0;
268
269 /* Called before init function. The function will handle this. */
270 if (!ctx)
271 goto set_param_out;
272
273 err = damon_lru_sort_turn(enable);
274 if (err)
275 return err;
276
277set_param_out:
278 enabled = enable;
279 return err;
280}
281
282static const struct kernel_param_ops enabled_param_ops = {
283 .set = damon_lru_sort_enabled_store,
284 .get = param_get_bool,
285};
286
287module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
288MODULE_PARM_DESC(enabled,
289 "Enable or disable DAMON_LRU_SORT (default: disabled)");
290
291static int damon_lru_sort_handle_commit_inputs(void)
292{
293 int err;
294
295 if (!commit_inputs)
296 return 0;
297
298 err = damon_lru_sort_apply_parameters();
299 commit_inputs = false;
300 return err;
301}
302
303static int damon_lru_sort_after_aggregation(struct damon_ctx *c)
304{
305 struct damos *s;
306
307 /* update the stats parameter */
308 damon_for_each_scheme(s, c) {
309 if (s->action == DAMOS_LRU_PRIO)
310 damon_lru_sort_hot_stat = s->stat;
311 else if (s->action == DAMOS_LRU_DEPRIO)
312 damon_lru_sort_cold_stat = s->stat;
313 }
314
315 return damon_lru_sort_handle_commit_inputs();
316}
317
318static int damon_lru_sort_after_wmarks_check(struct damon_ctx *c)
319{
320 return damon_lru_sort_handle_commit_inputs();
321}
322
323static int __init damon_lru_sort_init(void)
324{
325 int err = damon_modules_new_paddr_ctx_target(&ctx, &target);
326
327 if (err)
328 return err;
329
330 ctx->callback.after_wmarks_check = damon_lru_sort_after_wmarks_check;
331 ctx->callback.after_aggregation = damon_lru_sort_after_aggregation;
332
333 /* 'enabled' has set before this function, probably via command line */
334 if (enabled)
335 err = damon_lru_sort_turn(true);
336
337 return err;
338}
339
340module_init(damon_lru_sort_init);