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-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c698
1 files changed, 225 insertions, 473 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index d7f774bb49dd..bdaab9206303 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -10,24 +10,23 @@
10 * published by the Free Software Foundation. 10 * published by the Free Software Foundation.
11 */ 11 */
12 12
13#include <linux/kernel.h> 13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14#include <linux/module.h> 14
15#include <linux/init.h>
16#include <linux/cpufreq.h> 15#include <linux/cpufreq.h>
17#include <linux/cpu.h> 16#include <linux/init.h>
18#include <linux/jiffies.h> 17#include <linux/kernel.h>
19#include <linux/kernel_stat.h> 18#include <linux/kernel_stat.h>
19#include <linux/kobject.h>
20#include <linux/module.h>
20#include <linux/mutex.h> 21#include <linux/mutex.h>
21#include <linux/hrtimer.h> 22#include <linux/percpu-defs.h>
23#include <linux/sysfs.h>
22#include <linux/tick.h> 24#include <linux/tick.h>
23#include <linux/ktime.h> 25#include <linux/types.h>
24#include <linux/sched.h>
25 26
26/* 27#include "cpufreq_governor.h"
27 * dbs is used in this file as a shortform for demandbased switching
28 * It helps to keep variable names smaller, simpler
29 */
30 28
29/* On-demand governor macors */
31#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10) 30#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10)
32#define DEF_FREQUENCY_UP_THRESHOLD (80) 31#define DEF_FREQUENCY_UP_THRESHOLD (80)
33#define DEF_SAMPLING_DOWN_FACTOR (1) 32#define DEF_SAMPLING_DOWN_FACTOR (1)
@@ -38,80 +37,10 @@
38#define MIN_FREQUENCY_UP_THRESHOLD (11) 37#define MIN_FREQUENCY_UP_THRESHOLD (11)
39#define MAX_FREQUENCY_UP_THRESHOLD (100) 38#define MAX_FREQUENCY_UP_THRESHOLD (100)
40 39
41/* 40static struct dbs_data od_dbs_data;
42 * The polling frequency of this governor depends on the capability of 41static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info);
43 * the processor. Default polling frequency is 1000 times the transition
44 * latency of the processor. The governor will work on any processor with
45 * transition latency <= 10mS, using appropriate sampling
46 * rate.
47 * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
48 * this governor will not work.
49 * All times here are in uS.
50 */
51#define MIN_SAMPLING_RATE_RATIO (2)
52
53static unsigned int min_sampling_rate;
54
55#define LATENCY_MULTIPLIER (1000)
56#define MIN_LATENCY_MULTIPLIER (100)
57#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
58
59static void do_dbs_timer(struct work_struct *work);
60static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
61 unsigned int event);
62
63#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
64static
65#endif
66struct cpufreq_governor cpufreq_gov_ondemand = {
67 .name = "ondemand",
68 .governor = cpufreq_governor_dbs,
69 .max_transition_latency = TRANSITION_LATENCY_LIMIT,
70 .owner = THIS_MODULE,
71};
72
73/* Sampling types */
74enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
75
76struct cpu_dbs_info_s {
77 cputime64_t prev_cpu_idle;
78 cputime64_t prev_cpu_iowait;
79 cputime64_t prev_cpu_wall;
80 cputime64_t prev_cpu_nice;
81 struct cpufreq_policy *cur_policy;
82 struct delayed_work work;
83 struct cpufreq_frequency_table *freq_table;
84 unsigned int freq_lo;
85 unsigned int freq_lo_jiffies;
86 unsigned int freq_hi_jiffies;
87 unsigned int rate_mult;
88 int cpu;
89 unsigned int sample_type:1;
90 /*
91 * percpu mutex that serializes governor limit change with
92 * do_dbs_timer invocation. We do not want do_dbs_timer to run
93 * when user is changing the governor or limits.
94 */
95 struct mutex timer_mutex;
96};
97static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info);
98
99static unsigned int dbs_enable; /* number of CPUs using this policy */
100 42
101/* 43static struct od_dbs_tuners od_tuners = {
102 * dbs_mutex protects dbs_enable in governor start/stop.
103 */
104static DEFINE_MUTEX(dbs_mutex);
105
106static struct dbs_tuners {
107 unsigned int sampling_rate;
108 unsigned int up_threshold;
109 unsigned int down_differential;
110 unsigned int ignore_nice;
111 unsigned int sampling_down_factor;
112 unsigned int powersave_bias;
113 unsigned int io_is_busy;
114} dbs_tuners_ins = {
115 .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, 44 .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
116 .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, 45 .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
117 .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, 46 .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
@@ -119,14 +48,35 @@ static struct dbs_tuners {
119 .powersave_bias = 0, 48 .powersave_bias = 0,
120}; 49};
121 50
122static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall) 51static void ondemand_powersave_bias_init_cpu(int cpu)
123{ 52{
124 u64 iowait_time = get_cpu_iowait_time_us(cpu, wall); 53 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
125 54
126 if (iowait_time == -1ULL) 55 dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
127 return 0; 56 dbs_info->freq_lo = 0;
57}
128 58
129 return iowait_time; 59/*
60 * Not all CPUs want IO time to be accounted as busy; this depends on how
61 * efficient idling at a higher frequency/voltage is.
62 * Pavel Machek says this is not so for various generations of AMD and old
63 * Intel systems.
64 * Mike Chan (androidlcom) calis this is also not true for ARM.
65 * Because of this, whitelist specific known (series) of CPUs by default, and
66 * leave all others up to the user.
67 */
68static int should_io_be_busy(void)
69{
70#if defined(CONFIG_X86)
71 /*
72 * For Intel, Core 2 (model 15) andl later have an efficient idle.
73 */
74 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
75 boot_cpu_data.x86 == 6 &&
76 boot_cpu_data.x86_model >= 15)
77 return 1;
78#endif
79 return 0;
130} 80}
131 81
132/* 82/*
@@ -135,14 +85,13 @@ static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wal
135 * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. 85 * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
136 */ 86 */
137static unsigned int powersave_bias_target(struct cpufreq_policy *policy, 87static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
138 unsigned int freq_next, 88 unsigned int freq_next, unsigned int relation)
139 unsigned int relation)
140{ 89{
141 unsigned int freq_req, freq_reduc, freq_avg; 90 unsigned int freq_req, freq_reduc, freq_avg;
142 unsigned int freq_hi, freq_lo; 91 unsigned int freq_hi, freq_lo;
143 unsigned int index = 0; 92 unsigned int index = 0;
144 unsigned int jiffies_total, jiffies_hi, jiffies_lo; 93 unsigned int jiffies_total, jiffies_hi, jiffies_lo;
145 struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, 94 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
146 policy->cpu); 95 policy->cpu);
147 96
148 if (!dbs_info->freq_table) { 97 if (!dbs_info->freq_table) {
@@ -154,7 +103,7 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
154 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, 103 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next,
155 relation, &index); 104 relation, &index);
156 freq_req = dbs_info->freq_table[index].frequency; 105 freq_req = dbs_info->freq_table[index].frequency;
157 freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000; 106 freq_reduc = freq_req * od_tuners.powersave_bias / 1000;
158 freq_avg = freq_req - freq_reduc; 107 freq_avg = freq_req - freq_reduc;
159 108
160 /* Find freq bounds for freq_avg in freq_table */ 109 /* Find freq bounds for freq_avg in freq_table */
@@ -173,7 +122,7 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
173 dbs_info->freq_lo_jiffies = 0; 122 dbs_info->freq_lo_jiffies = 0;
174 return freq_lo; 123 return freq_lo;
175 } 124 }
176 jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); 125 jiffies_total = usecs_to_jiffies(od_tuners.sampling_rate);
177 jiffies_hi = (freq_avg - freq_lo) * jiffies_total; 126 jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
178 jiffies_hi += ((freq_hi - freq_lo) / 2); 127 jiffies_hi += ((freq_hi - freq_lo) / 2);
179 jiffies_hi /= (freq_hi - freq_lo); 128 jiffies_hi /= (freq_hi - freq_lo);
@@ -184,13 +133,6 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
184 return freq_hi; 133 return freq_hi;
185} 134}
186 135
187static void ondemand_powersave_bias_init_cpu(int cpu)
188{
189 struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
190 dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
191 dbs_info->freq_lo = 0;
192}
193
194static void ondemand_powersave_bias_init(void) 136static void ondemand_powersave_bias_init(void)
195{ 137{
196 int i; 138 int i;
@@ -199,53 +141,138 @@ static void ondemand_powersave_bias_init(void)
199 } 141 }
200} 142}
201 143
202/************************** sysfs interface ************************/ 144static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
145{
146 if (od_tuners.powersave_bias)
147 freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
148 else if (p->cur == p->max)
149 return;
203 150
204static ssize_t show_sampling_rate_min(struct kobject *kobj, 151 __cpufreq_driver_target(p, freq, od_tuners.powersave_bias ?
205 struct attribute *attr, char *buf) 152 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
153}
154
155/*
156 * Every sampling_rate, we check, if current idle time is less than 20%
157 * (default), then we try to increase frequency Every sampling_rate, we look for
158 * a the lowest frequency which can sustain the load while keeping idle time
159 * over 30%. If such a frequency exist, we try to decrease to this frequency.
160 *
161 * Any frequency increase takes it to the maximum frequency. Frequency reduction
162 * happens at minimum steps of 5% (default) of current frequency
163 */
164static void od_check_cpu(int cpu, unsigned int load_freq)
206{ 165{
207 return sprintf(buf, "%u\n", min_sampling_rate); 166 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
167 struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
168
169 dbs_info->freq_lo = 0;
170
171 /* Check for frequency increase */
172 if (load_freq > od_tuners.up_threshold * policy->cur) {
173 /* If switching to max speed, apply sampling_down_factor */
174 if (policy->cur < policy->max)
175 dbs_info->rate_mult =
176 od_tuners.sampling_down_factor;
177 dbs_freq_increase(policy, policy->max);
178 return;
179 }
180
181 /* Check for frequency decrease */
182 /* if we cannot reduce the frequency anymore, break out early */
183 if (policy->cur == policy->min)
184 return;
185
186 /*
187 * The optimal frequency is the frequency that is the lowest that can
188 * support the current CPU usage without triggering the up policy. To be
189 * safe, we focus 10 points under the threshold.
190 */
191 if (load_freq < (od_tuners.up_threshold - od_tuners.down_differential) *
192 policy->cur) {
193 unsigned int freq_next;
194 freq_next = load_freq / (od_tuners.up_threshold -
195 od_tuners.down_differential);
196
197 /* No longer fully busy, reset rate_mult */
198 dbs_info->rate_mult = 1;
199
200 if (freq_next < policy->min)
201 freq_next = policy->min;
202
203 if (!od_tuners.powersave_bias) {
204 __cpufreq_driver_target(policy, freq_next,
205 CPUFREQ_RELATION_L);
206 } else {
207 int freq = powersave_bias_target(policy, freq_next,
208 CPUFREQ_RELATION_L);
209 __cpufreq_driver_target(policy, freq,
210 CPUFREQ_RELATION_L);
211 }
212 }
208} 213}
209 214
210define_one_global_ro(sampling_rate_min); 215static void od_dbs_timer(struct work_struct *work)
216{
217 struct od_cpu_dbs_info_s *dbs_info =
218 container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work);
219 unsigned int cpu = dbs_info->cdbs.cpu;
220 int delay, sample_type = dbs_info->sample_type;
211 221
212/* cpufreq_ondemand Governor Tunables */ 222 mutex_lock(&dbs_info->cdbs.timer_mutex);
213#define show_one(file_name, object) \ 223
214static ssize_t show_##file_name \ 224 /* Common NORMAL_SAMPLE setup */
215(struct kobject *kobj, struct attribute *attr, char *buf) \ 225 dbs_info->sample_type = OD_NORMAL_SAMPLE;
216{ \ 226 if (sample_type == OD_SUB_SAMPLE) {
217 return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ 227 delay = dbs_info->freq_lo_jiffies;
228 __cpufreq_driver_target(dbs_info->cdbs.cur_policy,
229 dbs_info->freq_lo, CPUFREQ_RELATION_H);
230 } else {
231 dbs_check_cpu(&od_dbs_data, cpu);
232 if (dbs_info->freq_lo) {
233 /* Setup timer for SUB_SAMPLE */
234 dbs_info->sample_type = OD_SUB_SAMPLE;
235 delay = dbs_info->freq_hi_jiffies;
236 } else {
237 delay = delay_for_sampling_rate(dbs_info->rate_mult);
238 }
239 }
240
241 schedule_delayed_work_on(cpu, &dbs_info->cdbs.work, delay);
242 mutex_unlock(&dbs_info->cdbs.timer_mutex);
243}
244
245/************************** sysfs interface ************************/
246
247static ssize_t show_sampling_rate_min(struct kobject *kobj,
248 struct attribute *attr, char *buf)
249{
250 return sprintf(buf, "%u\n", od_dbs_data.min_sampling_rate);
218} 251}
219show_one(sampling_rate, sampling_rate);
220show_one(io_is_busy, io_is_busy);
221show_one(up_threshold, up_threshold);
222show_one(sampling_down_factor, sampling_down_factor);
223show_one(ignore_nice_load, ignore_nice);
224show_one(powersave_bias, powersave_bias);
225 252
226/** 253/**
227 * update_sampling_rate - update sampling rate effective immediately if needed. 254 * update_sampling_rate - update sampling rate effective immediately if needed.
228 * @new_rate: new sampling rate 255 * @new_rate: new sampling rate
229 * 256 *
230 * If new rate is smaller than the old, simply updaing 257 * If new rate is smaller than the old, simply updaing
231 * dbs_tuners_int.sampling_rate might not be appropriate. For example, 258 * dbs_tuners_int.sampling_rate might not be appropriate. For example, if the
232 * if the original sampling_rate was 1 second and the requested new sampling 259 * original sampling_rate was 1 second and the requested new sampling rate is 10
233 * rate is 10 ms because the user needs immediate reaction from ondemand 260 * ms because the user needs immediate reaction from ondemand governor, but not
234 * governor, but not sure if higher frequency will be required or not, 261 * sure if higher frequency will be required or not, then, the governor may
235 * then, the governor may change the sampling rate too late; up to 1 second 262 * change the sampling rate too late; up to 1 second later. Thus, if we are
236 * later. Thus, if we are reducing the sampling rate, we need to make the 263 * reducing the sampling rate, we need to make the new value effective
237 * new value effective immediately. 264 * immediately.
238 */ 265 */
239static void update_sampling_rate(unsigned int new_rate) 266static void update_sampling_rate(unsigned int new_rate)
240{ 267{
241 int cpu; 268 int cpu;
242 269
243 dbs_tuners_ins.sampling_rate = new_rate 270 od_tuners.sampling_rate = new_rate = max(new_rate,
244 = max(new_rate, min_sampling_rate); 271 od_dbs_data.min_sampling_rate);
245 272
246 for_each_online_cpu(cpu) { 273 for_each_online_cpu(cpu) {
247 struct cpufreq_policy *policy; 274 struct cpufreq_policy *policy;
248 struct cpu_dbs_info_s *dbs_info; 275 struct od_cpu_dbs_info_s *dbs_info;
249 unsigned long next_sampling, appointed_at; 276 unsigned long next_sampling, appointed_at;
250 277
251 policy = cpufreq_cpu_get(cpu); 278 policy = cpufreq_cpu_get(cpu);
@@ -254,28 +281,28 @@ static void update_sampling_rate(unsigned int new_rate)
254 dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu); 281 dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
255 cpufreq_cpu_put(policy); 282 cpufreq_cpu_put(policy);
256 283
257 mutex_lock(&dbs_info->timer_mutex); 284 mutex_lock(&dbs_info->cdbs.timer_mutex);
258 285
259 if (!delayed_work_pending(&dbs_info->work)) { 286 if (!delayed_work_pending(&dbs_info->cdbs.work)) {
260 mutex_unlock(&dbs_info->timer_mutex); 287 mutex_unlock(&dbs_info->cdbs.timer_mutex);
261 continue; 288 continue;
262 } 289 }
263 290
264 next_sampling = jiffies + usecs_to_jiffies(new_rate); 291 next_sampling = jiffies + usecs_to_jiffies(new_rate);
265 appointed_at = dbs_info->work.timer.expires; 292 appointed_at = dbs_info->cdbs.work.timer.expires;
266
267 293
268 if (time_before(next_sampling, appointed_at)) { 294 if (time_before(next_sampling, appointed_at)) {
269 295
270 mutex_unlock(&dbs_info->timer_mutex); 296 mutex_unlock(&dbs_info->cdbs.timer_mutex);
271 cancel_delayed_work_sync(&dbs_info->work); 297 cancel_delayed_work_sync(&dbs_info->cdbs.work);
272 mutex_lock(&dbs_info->timer_mutex); 298 mutex_lock(&dbs_info->cdbs.timer_mutex);
273 299
274 schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, 300 schedule_delayed_work_on(dbs_info->cdbs.cpu,
275 usecs_to_jiffies(new_rate)); 301 &dbs_info->cdbs.work,
302 usecs_to_jiffies(new_rate));
276 303
277 } 304 }
278 mutex_unlock(&dbs_info->timer_mutex); 305 mutex_unlock(&dbs_info->cdbs.timer_mutex);
279 } 306 }
280} 307}
281 308
@@ -300,7 +327,7 @@ static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
300 ret = sscanf(buf, "%u", &input); 327 ret = sscanf(buf, "%u", &input);
301 if (ret != 1) 328 if (ret != 1)
302 return -EINVAL; 329 return -EINVAL;
303 dbs_tuners_ins.io_is_busy = !!input; 330 od_tuners.io_is_busy = !!input;
304 return count; 331 return count;
305} 332}
306 333
@@ -315,7 +342,7 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
315 input < MIN_FREQUENCY_UP_THRESHOLD) { 342 input < MIN_FREQUENCY_UP_THRESHOLD) {
316 return -EINVAL; 343 return -EINVAL;
317 } 344 }
318 dbs_tuners_ins.up_threshold = input; 345 od_tuners.up_threshold = input;
319 return count; 346 return count;
320} 347}
321 348
@@ -328,12 +355,12 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
328 355
329 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) 356 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
330 return -EINVAL; 357 return -EINVAL;
331 dbs_tuners_ins.sampling_down_factor = input; 358 od_tuners.sampling_down_factor = input;
332 359
333 /* Reset down sampling multiplier in case it was active */ 360 /* Reset down sampling multiplier in case it was active */
334 for_each_online_cpu(j) { 361 for_each_online_cpu(j) {
335 struct cpu_dbs_info_s *dbs_info; 362 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
336 dbs_info = &per_cpu(od_cpu_dbs_info, j); 363 j);
337 dbs_info->rate_mult = 1; 364 dbs_info->rate_mult = 1;
338 } 365 }
339 return count; 366 return count;
@@ -354,19 +381,20 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
354 if (input > 1) 381 if (input > 1)
355 input = 1; 382 input = 1;
356 383
357 if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ 384 if (input == od_tuners.ignore_nice) { /* nothing to do */
358 return count; 385 return count;
359 } 386 }
360 dbs_tuners_ins.ignore_nice = input; 387 od_tuners.ignore_nice = input;
361 388
362 /* we need to re-evaluate prev_cpu_idle */ 389 /* we need to re-evaluate prev_cpu_idle */
363 for_each_online_cpu(j) { 390 for_each_online_cpu(j) {
364 struct cpu_dbs_info_s *dbs_info; 391 struct od_cpu_dbs_info_s *dbs_info;
365 dbs_info = &per_cpu(od_cpu_dbs_info, j); 392 dbs_info = &per_cpu(od_cpu_dbs_info, j);
366 dbs_info->prev_cpu_idle = get_cpu_idle_time(j, 393 dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
367 &dbs_info->prev_cpu_wall); 394 &dbs_info->cdbs.prev_cpu_wall);
368 if (dbs_tuners_ins.ignore_nice) 395 if (od_tuners.ignore_nice)
369 dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE]; 396 dbs_info->cdbs.prev_cpu_nice =
397 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
370 398
371 } 399 }
372 return count; 400 return count;
@@ -385,17 +413,25 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
385 if (input > 1000) 413 if (input > 1000)
386 input = 1000; 414 input = 1000;
387 415
388 dbs_tuners_ins.powersave_bias = input; 416 od_tuners.powersave_bias = input;
389 ondemand_powersave_bias_init(); 417 ondemand_powersave_bias_init();
390 return count; 418 return count;
391} 419}
392 420
421show_one(od, sampling_rate, sampling_rate);
422show_one(od, io_is_busy, io_is_busy);
423show_one(od, up_threshold, up_threshold);
424show_one(od, sampling_down_factor, sampling_down_factor);
425show_one(od, ignore_nice_load, ignore_nice);
426show_one(od, powersave_bias, powersave_bias);
427
393define_one_global_rw(sampling_rate); 428define_one_global_rw(sampling_rate);
394define_one_global_rw(io_is_busy); 429define_one_global_rw(io_is_busy);
395define_one_global_rw(up_threshold); 430define_one_global_rw(up_threshold);
396define_one_global_rw(sampling_down_factor); 431define_one_global_rw(sampling_down_factor);
397define_one_global_rw(ignore_nice_load); 432define_one_global_rw(ignore_nice_load);
398define_one_global_rw(powersave_bias); 433define_one_global_rw(powersave_bias);
434define_one_global_ro(sampling_rate_min);
399 435
400static struct attribute *dbs_attributes[] = { 436static struct attribute *dbs_attributes[] = {
401 &sampling_rate_min.attr, 437 &sampling_rate_min.attr,
@@ -408,354 +444,71 @@ static struct attribute *dbs_attributes[] = {
408 NULL 444 NULL
409}; 445};
410 446
411static struct attribute_group dbs_attr_group = { 447static struct attribute_group od_attr_group = {
412 .attrs = dbs_attributes, 448 .attrs = dbs_attributes,
413 .name = "ondemand", 449 .name = "ondemand",
414}; 450};
415 451
416/************************** sysfs end ************************/ 452/************************** sysfs end ************************/
417 453
418static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq) 454define_get_cpu_dbs_routines(od_cpu_dbs_info);
419{
420 if (dbs_tuners_ins.powersave_bias)
421 freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
422 else if (p->cur == p->max)
423 return;
424
425 __cpufreq_driver_target(p, freq, dbs_tuners_ins.powersave_bias ?
426 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
427}
428
429static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
430{
431 unsigned int max_load_freq;
432
433 struct cpufreq_policy *policy;
434 unsigned int j;
435
436 this_dbs_info->freq_lo = 0;
437 policy = this_dbs_info->cur_policy;
438
439 /*
440 * Every sampling_rate, we check, if current idle time is less
441 * than 20% (default), then we try to increase frequency
442 * Every sampling_rate, we look for a the lowest
443 * frequency which can sustain the load while keeping idle time over
444 * 30%. If such a frequency exist, we try to decrease to this frequency.
445 *
446 * Any frequency increase takes it to the maximum frequency.
447 * Frequency reduction happens at minimum steps of
448 * 5% (default) of current frequency
449 */
450
451 /* Get Absolute Load - in terms of freq */
452 max_load_freq = 0;
453
454 for_each_cpu(j, policy->cpus) {
455 struct cpu_dbs_info_s *j_dbs_info;
456 cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
457 unsigned int idle_time, wall_time, iowait_time;
458 unsigned int load, load_freq;
459 int freq_avg;
460
461 j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
462
463 cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
464 cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
465
466 wall_time = (unsigned int)
467 (cur_wall_time - j_dbs_info->prev_cpu_wall);
468 j_dbs_info->prev_cpu_wall = cur_wall_time;
469
470 idle_time = (unsigned int)
471 (cur_idle_time - j_dbs_info->prev_cpu_idle);
472 j_dbs_info->prev_cpu_idle = cur_idle_time;
473
474 iowait_time = (unsigned int)
475 (cur_iowait_time - j_dbs_info->prev_cpu_iowait);
476 j_dbs_info->prev_cpu_iowait = cur_iowait_time;
477
478 if (dbs_tuners_ins.ignore_nice) {
479 u64 cur_nice;
480 unsigned long cur_nice_jiffies;
481
482 cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
483 j_dbs_info->prev_cpu_nice;
484 /*
485 * Assumption: nice time between sampling periods will
486 * be less than 2^32 jiffies for 32 bit sys
487 */
488 cur_nice_jiffies = (unsigned long)
489 cputime64_to_jiffies64(cur_nice);
490
491 j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
492 idle_time += jiffies_to_usecs(cur_nice_jiffies);
493 }
494
495 /*
496 * For the purpose of ondemand, waiting for disk IO is an
497 * indication that you're performance critical, and not that
498 * the system is actually idle. So subtract the iowait time
499 * from the cpu idle time.
500 */
501
502 if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time)
503 idle_time -= iowait_time;
504 455
505 if (unlikely(!wall_time || wall_time < idle_time)) 456static struct od_ops od_ops = {
506 continue; 457 .io_busy = should_io_be_busy,
507 458 .powersave_bias_init_cpu = ondemand_powersave_bias_init_cpu,
508 load = 100 * (wall_time - idle_time) / wall_time; 459 .powersave_bias_target = powersave_bias_target,
509 460 .freq_increase = dbs_freq_increase,
510 freq_avg = __cpufreq_driver_getavg(policy, j); 461};
511 if (freq_avg <= 0)
512 freq_avg = policy->cur;
513
514 load_freq = load * freq_avg;
515 if (load_freq > max_load_freq)
516 max_load_freq = load_freq;
517 }
518
519 /* Check for frequency increase */
520 if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
521 /* If switching to max speed, apply sampling_down_factor */
522 if (policy->cur < policy->max)
523 this_dbs_info->rate_mult =
524 dbs_tuners_ins.sampling_down_factor;
525 dbs_freq_increase(policy, policy->max);
526 return;
527 }
528
529 /* Check for frequency decrease */
530 /* if we cannot reduce the frequency anymore, break out early */
531 if (policy->cur == policy->min)
532 return;
533
534 /*
535 * The optimal frequency is the frequency that is the lowest that
536 * can support the current CPU usage without triggering the up
537 * policy. To be safe, we focus 10 points under the threshold.
538 */
539 if (max_load_freq <
540 (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
541 policy->cur) {
542 unsigned int freq_next;
543 freq_next = max_load_freq /
544 (dbs_tuners_ins.up_threshold -
545 dbs_tuners_ins.down_differential);
546
547 /* No longer fully busy, reset rate_mult */
548 this_dbs_info->rate_mult = 1;
549
550 if (freq_next < policy->min)
551 freq_next = policy->min;
552
553 if (!dbs_tuners_ins.powersave_bias) {
554 __cpufreq_driver_target(policy, freq_next,
555 CPUFREQ_RELATION_L);
556 } else {
557 int freq = powersave_bias_target(policy, freq_next,
558 CPUFREQ_RELATION_L);
559 __cpufreq_driver_target(policy, freq,
560 CPUFREQ_RELATION_L);
561 }
562 }
563}
564
565static void do_dbs_timer(struct work_struct *work)
566{
567 struct cpu_dbs_info_s *dbs_info =
568 container_of(work, struct cpu_dbs_info_s, work.work);
569 unsigned int cpu = dbs_info->cpu;
570 int sample_type = dbs_info->sample_type;
571
572 int delay;
573
574 mutex_lock(&dbs_info->timer_mutex);
575
576 /* Common NORMAL_SAMPLE setup */
577 dbs_info->sample_type = DBS_NORMAL_SAMPLE;
578 if (!dbs_tuners_ins.powersave_bias ||
579 sample_type == DBS_NORMAL_SAMPLE) {
580 dbs_check_cpu(dbs_info);
581 if (dbs_info->freq_lo) {
582 /* Setup timer for SUB_SAMPLE */
583 dbs_info->sample_type = DBS_SUB_SAMPLE;
584 delay = dbs_info->freq_hi_jiffies;
585 } else {
586 /* We want all CPUs to do sampling nearly on
587 * same jiffy
588 */
589 delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate
590 * dbs_info->rate_mult);
591
592 if (num_online_cpus() > 1)
593 delay -= jiffies % delay;
594 }
595 } else {
596 __cpufreq_driver_target(dbs_info->cur_policy,
597 dbs_info->freq_lo, CPUFREQ_RELATION_H);
598 delay = dbs_info->freq_lo_jiffies;
599 }
600 schedule_delayed_work_on(cpu, &dbs_info->work, delay);
601 mutex_unlock(&dbs_info->timer_mutex);
602}
603
604static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
605{
606 /* We want all CPUs to do sampling nearly on same jiffy */
607 int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
608
609 if (num_online_cpus() > 1)
610 delay -= jiffies % delay;
611 462
612 dbs_info->sample_type = DBS_NORMAL_SAMPLE; 463static struct dbs_data od_dbs_data = {
613 INIT_DEFERRABLE_WORK(&dbs_info->work, do_dbs_timer); 464 .governor = GOV_ONDEMAND,
614 schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay); 465 .attr_group = &od_attr_group,
615} 466 .tuners = &od_tuners,
467 .get_cpu_cdbs = get_cpu_cdbs,
468 .get_cpu_dbs_info_s = get_cpu_dbs_info_s,
469 .gov_dbs_timer = od_dbs_timer,
470 .gov_check_cpu = od_check_cpu,
471 .gov_ops = &od_ops,
472};
616 473
617static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) 474static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,
475 unsigned int event)
618{ 476{
619 cancel_delayed_work_sync(&dbs_info->work); 477 return cpufreq_governor_dbs(&od_dbs_data, policy, event);
620} 478}
621 479
622/* 480#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
623 * Not all CPUs want IO time to be accounted as busy; this dependson how 481static
624 * efficient idling at a higher frequency/voltage is.
625 * Pavel Machek says this is not so for various generations of AMD and old
626 * Intel systems.
627 * Mike Chan (androidlcom) calis this is also not true for ARM.
628 * Because of this, whitelist specific known (series) of CPUs by default, and
629 * leave all others up to the user.
630 */
631static int should_io_be_busy(void)
632{
633#if defined(CONFIG_X86)
634 /*
635 * For Intel, Core 2 (model 15) andl later have an efficient idle.
636 */
637 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
638 boot_cpu_data.x86 == 6 &&
639 boot_cpu_data.x86_model >= 15)
640 return 1;
641#endif 482#endif
642 return 0; 483struct cpufreq_governor cpufreq_gov_ondemand = {
643} 484 .name = "ondemand",
644 485 .governor = od_cpufreq_governor_dbs,
645static int cpufreq_governor_dbs(struct cpufreq_policy *policy, 486 .max_transition_latency = TRANSITION_LATENCY_LIMIT,
646 unsigned int event) 487 .owner = THIS_MODULE,
647{ 488};
648 unsigned int cpu = policy->cpu;
649 struct cpu_dbs_info_s *this_dbs_info;
650 unsigned int j;
651 int rc;
652
653 this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
654
655 switch (event) {
656 case CPUFREQ_GOV_START:
657 if ((!cpu_online(cpu)) || (!policy->cur))
658 return -EINVAL;
659
660 mutex_lock(&dbs_mutex);
661
662 dbs_enable++;
663 for_each_cpu(j, policy->cpus) {
664 struct cpu_dbs_info_s *j_dbs_info;
665 j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
666 j_dbs_info->cur_policy = policy;
667
668 j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
669 &j_dbs_info->prev_cpu_wall);
670 if (dbs_tuners_ins.ignore_nice)
671 j_dbs_info->prev_cpu_nice =
672 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
673 }
674 this_dbs_info->cpu = cpu;
675 this_dbs_info->rate_mult = 1;
676 ondemand_powersave_bias_init_cpu(cpu);
677 /*
678 * Start the timerschedule work, when this governor
679 * is used for first time
680 */
681 if (dbs_enable == 1) {
682 unsigned int latency;
683
684 rc = sysfs_create_group(cpufreq_global_kobject,
685 &dbs_attr_group);
686 if (rc) {
687 mutex_unlock(&dbs_mutex);
688 return rc;
689 }
690
691 /* policy latency is in nS. Convert it to uS first */
692 latency = policy->cpuinfo.transition_latency / 1000;
693 if (latency == 0)
694 latency = 1;
695 /* Bring kernel and HW constraints together */
696 min_sampling_rate = max(min_sampling_rate,
697 MIN_LATENCY_MULTIPLIER * latency);
698 dbs_tuners_ins.sampling_rate =
699 max(min_sampling_rate,
700 latency * LATENCY_MULTIPLIER);
701 dbs_tuners_ins.io_is_busy = should_io_be_busy();
702 }
703 mutex_unlock(&dbs_mutex);
704
705 mutex_init(&this_dbs_info->timer_mutex);
706 dbs_timer_init(this_dbs_info);
707 break;
708
709 case CPUFREQ_GOV_STOP:
710 dbs_timer_exit(this_dbs_info);
711
712 mutex_lock(&dbs_mutex);
713 mutex_destroy(&this_dbs_info->timer_mutex);
714 dbs_enable--;
715 mutex_unlock(&dbs_mutex);
716 if (!dbs_enable)
717 sysfs_remove_group(cpufreq_global_kobject,
718 &dbs_attr_group);
719
720 break;
721
722 case CPUFREQ_GOV_LIMITS:
723 mutex_lock(&this_dbs_info->timer_mutex);
724 if (policy->max < this_dbs_info->cur_policy->cur)
725 __cpufreq_driver_target(this_dbs_info->cur_policy,
726 policy->max, CPUFREQ_RELATION_H);
727 else if (policy->min > this_dbs_info->cur_policy->cur)
728 __cpufreq_driver_target(this_dbs_info->cur_policy,
729 policy->min, CPUFREQ_RELATION_L);
730 dbs_check_cpu(this_dbs_info);
731 mutex_unlock(&this_dbs_info->timer_mutex);
732 break;
733 }
734 return 0;
735}
736 489
737static int __init cpufreq_gov_dbs_init(void) 490static int __init cpufreq_gov_dbs_init(void)
738{ 491{
739 u64 idle_time; 492 u64 idle_time;
740 int cpu = get_cpu(); 493 int cpu = get_cpu();
741 494
495 mutex_init(&od_dbs_data.mutex);
742 idle_time = get_cpu_idle_time_us(cpu, NULL); 496 idle_time = get_cpu_idle_time_us(cpu, NULL);
743 put_cpu(); 497 put_cpu();
744 if (idle_time != -1ULL) { 498 if (idle_time != -1ULL) {
745 /* Idle micro accounting is supported. Use finer thresholds */ 499 /* Idle micro accounting is supported. Use finer thresholds */
746 dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; 500 od_tuners.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
747 dbs_tuners_ins.down_differential = 501 od_tuners.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
748 MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
749 /* 502 /*
750 * In nohz/micro accounting case we set the minimum frequency 503 * In nohz/micro accounting case we set the minimum frequency
751 * not depending on HZ, but fixed (very low). The deferred 504 * not depending on HZ, but fixed (very low). The deferred
752 * timer might skip some samples if idle/sleeping as needed. 505 * timer might skip some samples if idle/sleeping as needed.
753 */ 506 */
754 min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; 507 od_dbs_data.min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
755 } else { 508 } else {
756 /* For correct statistics, we need 10 ticks for each measure */ 509 /* For correct statistics, we need 10 ticks for each measure */
757 min_sampling_rate = 510 od_dbs_data.min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
758 MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); 511 jiffies_to_usecs(10);
759 } 512 }
760 513
761 return cpufreq_register_governor(&cpufreq_gov_ondemand); 514 return cpufreq_register_governor(&cpufreq_gov_ondemand);
@@ -766,7 +519,6 @@ static void __exit cpufreq_gov_dbs_exit(void)
766 cpufreq_unregister_governor(&cpufreq_gov_ondemand); 519 cpufreq_unregister_governor(&cpufreq_gov_ondemand);
767} 520}
768 521
769
770MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); 522MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
771MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); 523MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
772MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " 524MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "