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108c35a9 | 1 | // SPDX-License-Identifier: GPL-2.0 |
9bdcb44e RW |
2 | /* |
3 | * CPUFreq governor based on scheduler-provided CPU utilization data. | |
4 | * | |
5 | * Copyright (C) 2016, Intel Corporation | |
6 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
9bdcb44e RW |
7 | */ |
8 | ||
60f05e86 VK |
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
10 | ||
9bdcb44e RW |
11 | #include "sched.h" |
12 | ||
938e5e4b | 13 | #include <linux/sched/cpufreq.h> |
325ea10c IM |
14 | #include <trace/events/power.h> |
15 | ||
9eca544b RW |
16 | #define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8) |
17 | ||
9bdcb44e | 18 | struct sugov_tunables { |
97fb7a0a IM |
19 | struct gov_attr_set attr_set; |
20 | unsigned int rate_limit_us; | |
9bdcb44e RW |
21 | }; |
22 | ||
23 | struct sugov_policy { | |
97fb7a0a IM |
24 | struct cpufreq_policy *policy; |
25 | ||
26 | struct sugov_tunables *tunables; | |
27 | struct list_head tunables_hook; | |
28 | ||
29 | raw_spinlock_t update_lock; /* For shared policies */ | |
30 | u64 last_freq_update_time; | |
31 | s64 freq_update_delay_ns; | |
32 | unsigned int next_freq; | |
33 | unsigned int cached_raw_freq; | |
34 | ||
35 | /* The next fields are only needed if fast switch cannot be used: */ | |
36 | struct irq_work irq_work; | |
37 | struct kthread_work work; | |
38 | struct mutex work_lock; | |
39 | struct kthread_worker worker; | |
40 | struct task_struct *thread; | |
41 | bool work_in_progress; | |
42 | ||
600f5bad | 43 | bool limits_changed; |
97fb7a0a | 44 | bool need_freq_update; |
9bdcb44e RW |
45 | }; |
46 | ||
47 | struct sugov_cpu { | |
97fb7a0a IM |
48 | struct update_util_data update_util; |
49 | struct sugov_policy *sg_policy; | |
50 | unsigned int cpu; | |
9bdcb44e | 51 | |
97fb7a0a IM |
52 | bool iowait_boost_pending; |
53 | unsigned int iowait_boost; | |
fd7d5287 | 54 | u64 last_update; |
5cbea469 | 55 | |
8cc90515 | 56 | unsigned long bw_dl; |
97fb7a0a | 57 | unsigned long max; |
b7eaf1aa | 58 | |
97fb7a0a | 59 | /* The field below is for single-CPU policies only: */ |
b7eaf1aa | 60 | #ifdef CONFIG_NO_HZ_COMMON |
97fb7a0a | 61 | unsigned long saved_idle_calls; |
b7eaf1aa | 62 | #endif |
9bdcb44e RW |
63 | }; |
64 | ||
65 | static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); | |
66 | ||
67 | /************************ Governor internals ***********************/ | |
68 | ||
69 | static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) | |
70 | { | |
71 | s64 delta_ns; | |
72 | ||
674e7541 VK |
73 | /* |
74 | * Since cpufreq_update_util() is called with rq->lock held for | |
97fb7a0a | 75 | * the @target_cpu, our per-CPU data is fully serialized. |
674e7541 | 76 | * |
97fb7a0a | 77 | * However, drivers cannot in general deal with cross-CPU |
674e7541 | 78 | * requests, so while get_next_freq() will work, our |
c49cbc19 | 79 | * sugov_update_commit() call may not for the fast switching platforms. |
674e7541 VK |
80 | * |
81 | * Hence stop here for remote requests if they aren't supported | |
82 | * by the hardware, as calculating the frequency is pointless if | |
83 | * we cannot in fact act on it. | |
c49cbc19 VK |
84 | * |
85 | * For the slow switching platforms, the kthread is always scheduled on | |
86 | * the right set of CPUs and any CPU can find the next frequency and | |
87 | * schedule the kthread. | |
674e7541 | 88 | */ |
c49cbc19 | 89 | if (sg_policy->policy->fast_switch_enabled && |
03639978 | 90 | !cpufreq_this_cpu_can_update(sg_policy->policy)) |
674e7541 VK |
91 | return false; |
92 | ||
600f5bad VK |
93 | if (unlikely(sg_policy->limits_changed)) { |
94 | sg_policy->limits_changed = false; | |
95 | sg_policy->need_freq_update = true; | |
9bdcb44e | 96 | return true; |
600f5bad | 97 | } |
9bdcb44e RW |
98 | |
99 | delta_ns = time - sg_policy->last_freq_update_time; | |
97fb7a0a | 100 | |
9bdcb44e RW |
101 | return delta_ns >= sg_policy->freq_update_delay_ns; |
102 | } | |
103 | ||
a61dec74 RW |
104 | static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time, |
105 | unsigned int next_freq) | |
9bdcb44e | 106 | { |
38d4ea22 | 107 | if (sg_policy->next_freq == next_freq) |
a61dec74 | 108 | return false; |
38d4ea22 RW |
109 | |
110 | sg_policy->next_freq = next_freq; | |
9bdcb44e RW |
111 | sg_policy->last_freq_update_time = time; |
112 | ||
a61dec74 RW |
113 | return true; |
114 | } | |
9bdcb44e | 115 | |
a61dec74 RW |
116 | static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time, |
117 | unsigned int next_freq) | |
118 | { | |
119 | struct cpufreq_policy *policy = sg_policy->policy; | |
77c84dd1 | 120 | int cpu; |
a61dec74 RW |
121 | |
122 | if (!sugov_update_next_freq(sg_policy, time, next_freq)) | |
123 | return; | |
124 | ||
125 | next_freq = cpufreq_driver_fast_switch(policy, next_freq); | |
126 | if (!next_freq) | |
127 | return; | |
9bdcb44e | 128 | |
a61dec74 | 129 | policy->cur = next_freq; |
77c84dd1 DR |
130 | |
131 | if (trace_cpu_frequency_enabled()) { | |
132 | for_each_cpu(cpu, policy->cpus) | |
133 | trace_cpu_frequency(next_freq, cpu); | |
134 | } | |
a61dec74 RW |
135 | } |
136 | ||
137 | static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time, | |
138 | unsigned int next_freq) | |
139 | { | |
140 | if (!sugov_update_next_freq(sg_policy, time, next_freq)) | |
141 | return; | |
142 | ||
143 | if (!sg_policy->work_in_progress) { | |
9bdcb44e RW |
144 | sg_policy->work_in_progress = true; |
145 | irq_work_queue(&sg_policy->irq_work); | |
146 | } | |
147 | } | |
148 | ||
149 | /** | |
150 | * get_next_freq - Compute a new frequency for a given cpufreq policy. | |
655cb1eb | 151 | * @sg_policy: schedutil policy object to compute the new frequency for. |
9bdcb44e RW |
152 | * @util: Current CPU utilization. |
153 | * @max: CPU capacity. | |
154 | * | |
155 | * If the utilization is frequency-invariant, choose the new frequency to be | |
156 | * proportional to it, that is | |
157 | * | |
158 | * next_freq = C * max_freq * util / max | |
159 | * | |
160 | * Otherwise, approximate the would-be frequency-invariant utilization by | |
161 | * util_raw * (curr_freq / max_freq) which leads to | |
162 | * | |
163 | * next_freq = C * curr_freq * util_raw / max | |
164 | * | |
165 | * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8. | |
5cbea469 SM |
166 | * |
167 | * The lowest driver-supported frequency which is equal or greater than the raw | |
168 | * next_freq (as calculated above) is returned, subject to policy min/max and | |
169 | * cpufreq driver limitations. | |
9bdcb44e | 170 | */ |
655cb1eb VK |
171 | static unsigned int get_next_freq(struct sugov_policy *sg_policy, |
172 | unsigned long util, unsigned long max) | |
9bdcb44e | 173 | { |
5cbea469 | 174 | struct cpufreq_policy *policy = sg_policy->policy; |
9bdcb44e RW |
175 | unsigned int freq = arch_scale_freq_invariant() ? |
176 | policy->cpuinfo.max_freq : policy->cur; | |
177 | ||
938e5e4b | 178 | freq = map_util_freq(util, freq, max); |
5cbea469 | 179 | |
ecd28842 | 180 | if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) |
5cbea469 | 181 | return sg_policy->next_freq; |
ecd28842 VK |
182 | |
183 | sg_policy->need_freq_update = false; | |
6c4f0fa6 | 184 | sg_policy->cached_raw_freq = freq; |
5cbea469 | 185 | return cpufreq_driver_resolve_freq(policy, freq); |
9bdcb44e RW |
186 | } |
187 | ||
45f5519e PZ |
188 | /* |
189 | * This function computes an effective utilization for the given CPU, to be | |
190 | * used for frequency selection given the linear relation: f = u * f_max. | |
191 | * | |
192 | * The scheduler tracks the following metrics: | |
193 | * | |
194 | * cpu_util_{cfs,rt,dl,irq}() | |
195 | * cpu_bw_dl() | |
196 | * | |
197 | * Where the cfs,rt and dl util numbers are tracked with the same metric and | |
198 | * synchronized windows and are thus directly comparable. | |
199 | * | |
200 | * The cfs,rt,dl utilization are the running times measured with rq->clock_task | |
201 | * which excludes things like IRQ and steal-time. These latter are then accrued | |
202 | * in the irq utilization. | |
203 | * | |
204 | * The DL bandwidth number otoh is not a measured metric but a value computed | |
205 | * based on the task model parameters and gives the minimal utilization | |
206 | * required to meet deadlines. | |
207 | */ | |
af24bde8 PB |
208 | unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs, |
209 | unsigned long max, enum schedutil_type type, | |
210 | struct task_struct *p) | |
58919e83 | 211 | { |
938e5e4b QP |
212 | unsigned long dl_util, util, irq; |
213 | struct rq *rq = cpu_rq(cpu); | |
8f111bc3 | 214 | |
982d9cdc PB |
215 | if (!IS_BUILTIN(CONFIG_UCLAMP_TASK) && |
216 | type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) { | |
dfa444dc | 217 | return max; |
982d9cdc | 218 | } |
dfa444dc | 219 | |
45f5519e PZ |
220 | /* |
221 | * Early check to see if IRQ/steal time saturates the CPU, can be | |
222 | * because of inaccuracies in how we track these -- see | |
223 | * update_irq_load_avg(). | |
224 | */ | |
dfa444dc | 225 | irq = cpu_util_irq(rq); |
dfa444dc | 226 | if (unlikely(irq >= max)) |
9033ea11 VG |
227 | return max; |
228 | ||
45f5519e PZ |
229 | /* |
230 | * Because the time spend on RT/DL tasks is visible as 'lost' time to | |
231 | * CFS tasks and we use the same metric to track the effective | |
232 | * utilization (PELT windows are synchronized) we can directly add them | |
233 | * to obtain the CPU's actual utilization. | |
982d9cdc PB |
234 | * |
235 | * CFS and RT utilization can be boosted or capped, depending on | |
236 | * utilization clamp constraints requested by currently RUNNABLE | |
237 | * tasks. | |
238 | * When there are no CFS RUNNABLE tasks, clamps are released and | |
239 | * frequency will be gracefully reduced with the utilization decay. | |
45f5519e | 240 | */ |
982d9cdc PB |
241 | util = util_cfs + cpu_util_rt(rq); |
242 | if (type == FREQUENCY_UTIL) | |
af24bde8 | 243 | util = uclamp_util_with(rq, util, p); |
3ae117c6 | 244 | |
938e5e4b QP |
245 | dl_util = cpu_util_dl(rq); |
246 | ||
9033ea11 | 247 | /* |
938e5e4b QP |
248 | * For frequency selection we do not make cpu_util_dl() a permanent part |
249 | * of this sum because we want to use cpu_bw_dl() later on, but we need | |
250 | * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such | |
251 | * that we select f_max when there is no idle time. | |
45f5519e PZ |
252 | * |
253 | * NOTE: numerical errors or stop class might cause us to not quite hit | |
254 | * saturation when we should -- something for later. | |
9033ea11 | 255 | */ |
938e5e4b | 256 | if (util + dl_util >= max) |
9033ea11 | 257 | return max; |
8cc90515 | 258 | |
938e5e4b QP |
259 | /* |
260 | * OTOH, for energy computation we need the estimated running time, so | |
261 | * include util_dl and ignore dl_bw. | |
262 | */ | |
263 | if (type == ENERGY_UTIL) | |
264 | util += dl_util; | |
265 | ||
d4edd662 | 266 | /* |
45f5519e PZ |
267 | * There is still idle time; further improve the number by using the |
268 | * irq metric. Because IRQ/steal time is hidden from the task clock we | |
269 | * need to scale the task numbers: | |
8cc90515 | 270 | * |
5c3ceef9 QY |
271 | * max - irq |
272 | * U' = irq + --------- * U | |
273 | * max | |
45f5519e | 274 | */ |
2e62c474 | 275 | util = scale_irq_capacity(util, irq, max); |
45f5519e PZ |
276 | util += irq; |
277 | ||
278 | /* | |
8cc90515 VG |
279 | * Bandwidth required by DEADLINE must always be granted while, for |
280 | * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism | |
281 | * to gracefully reduce the frequency when no tasks show up for longer | |
8ecf04e1 PB |
282 | * periods of time. |
283 | * | |
45f5519e PZ |
284 | * Ideally we would like to set bw_dl as min/guaranteed freq and util + |
285 | * bw_dl as requested freq. However, cpufreq is not yet ready for such | |
286 | * an interface. So, we only do the latter for now. | |
d4edd662 | 287 | */ |
938e5e4b QP |
288 | if (type == FREQUENCY_UTIL) |
289 | util += cpu_bw_dl(rq); | |
290 | ||
291 | return min(max, util); | |
292 | } | |
293 | ||
294 | static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) | |
295 | { | |
296 | struct rq *rq = cpu_rq(sg_cpu->cpu); | |
297 | unsigned long util = cpu_util_cfs(rq); | |
8ec59c0f | 298 | unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); |
938e5e4b QP |
299 | |
300 | sg_cpu->max = max; | |
301 | sg_cpu->bw_dl = cpu_bw_dl(rq); | |
302 | ||
af24bde8 | 303 | return schedutil_cpu_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL, NULL); |
58919e83 RW |
304 | } |
305 | ||
fd7d5287 PB |
306 | /** |
307 | * sugov_iowait_reset() - Reset the IO boost status of a CPU. | |
308 | * @sg_cpu: the sugov data for the CPU to boost | |
309 | * @time: the update time from the caller | |
310 | * @set_iowait_boost: true if an IO boost has been requested | |
311 | * | |
312 | * The IO wait boost of a task is disabled after a tick since the last update | |
313 | * of a CPU. If a new IO wait boost is requested after more then a tick, then | |
9eca544b RW |
314 | * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy |
315 | * efficiency by ignoring sporadic wakeups from IO. | |
fd7d5287 PB |
316 | */ |
317 | static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time, | |
318 | bool set_iowait_boost) | |
21ca6d2c | 319 | { |
fd7d5287 | 320 | s64 delta_ns = time - sg_cpu->last_update; |
a5a0809b | 321 | |
fd7d5287 PB |
322 | /* Reset boost only if a tick has elapsed since last request */ |
323 | if (delta_ns <= TICK_NSEC) | |
324 | return false; | |
a5a0809b | 325 | |
9eca544b | 326 | sg_cpu->iowait_boost = set_iowait_boost ? IOWAIT_BOOST_MIN : 0; |
fd7d5287 | 327 | sg_cpu->iowait_boost_pending = set_iowait_boost; |
21ca6d2c | 328 | |
fd7d5287 PB |
329 | return true; |
330 | } | |
a5a0809b | 331 | |
fd7d5287 PB |
332 | /** |
333 | * sugov_iowait_boost() - Updates the IO boost status of a CPU. | |
334 | * @sg_cpu: the sugov data for the CPU to boost | |
335 | * @time: the update time from the caller | |
336 | * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait | |
337 | * | |
338 | * Each time a task wakes up after an IO operation, the CPU utilization can be | |
339 | * boosted to a certain utilization which doubles at each "frequent and | |
9eca544b RW |
340 | * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization |
341 | * of the maximum OPP. | |
342 | * | |
fd7d5287 PB |
343 | * To keep doubling, an IO boost has to be requested at least once per tick, |
344 | * otherwise we restart from the utilization of the minimum OPP. | |
345 | */ | |
346 | static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, | |
347 | unsigned int flags) | |
348 | { | |
349 | bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT; | |
350 | ||
351 | /* Reset boost if the CPU appears to have been idle enough */ | |
352 | if (sg_cpu->iowait_boost && | |
353 | sugov_iowait_reset(sg_cpu, time, set_iowait_boost)) | |
354 | return; | |
355 | ||
356 | /* Boost only tasks waking up after IO */ | |
357 | if (!set_iowait_boost) | |
358 | return; | |
359 | ||
360 | /* Ensure boost doubles only one time at each request */ | |
361 | if (sg_cpu->iowait_boost_pending) | |
362 | return; | |
363 | sg_cpu->iowait_boost_pending = true; | |
364 | ||
365 | /* Double the boost at each request */ | |
366 | if (sg_cpu->iowait_boost) { | |
a23314e9 PZ |
367 | sg_cpu->iowait_boost = |
368 | min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE); | |
fd7d5287 | 369 | return; |
21ca6d2c | 370 | } |
fd7d5287 PB |
371 | |
372 | /* First wakeup after IO: start with minimum boost */ | |
9eca544b | 373 | sg_cpu->iowait_boost = IOWAIT_BOOST_MIN; |
21ca6d2c RW |
374 | } |
375 | ||
fd7d5287 PB |
376 | /** |
377 | * sugov_iowait_apply() - Apply the IO boost to a CPU. | |
378 | * @sg_cpu: the sugov data for the cpu to boost | |
379 | * @time: the update time from the caller | |
380 | * @util: the utilization to (eventually) boost | |
381 | * @max: the maximum value the utilization can be boosted to | |
382 | * | |
383 | * A CPU running a task which woken up after an IO operation can have its | |
384 | * utilization boosted to speed up the completion of those IO operations. | |
385 | * The IO boost value is increased each time a task wakes up from IO, in | |
386 | * sugov_iowait_apply(), and it's instead decreased by this function, | |
387 | * each time an increase has not been requested (!iowait_boost_pending). | |
388 | * | |
389 | * A CPU which also appears to have been idle for at least one tick has also | |
390 | * its IO boost utilization reset. | |
391 | * | |
392 | * This mechanism is designed to boost high frequently IO waiting tasks, while | |
393 | * being more conservative on tasks which does sporadic IO operations. | |
394 | */ | |
a23314e9 PZ |
395 | static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, |
396 | unsigned long util, unsigned long max) | |
21ca6d2c | 397 | { |
a23314e9 | 398 | unsigned long boost; |
21ca6d2c | 399 | |
fd7d5287 | 400 | /* No boost currently required */ |
a5a0809b | 401 | if (!sg_cpu->iowait_boost) |
a23314e9 | 402 | return util; |
21ca6d2c | 403 | |
fd7d5287 PB |
404 | /* Reset boost if the CPU appears to have been idle enough */ |
405 | if (sugov_iowait_reset(sg_cpu, time, false)) | |
a23314e9 | 406 | return util; |
fd7d5287 | 407 | |
a23314e9 | 408 | if (!sg_cpu->iowait_boost_pending) { |
fd7d5287 | 409 | /* |
a23314e9 | 410 | * No boost pending; reduce the boost value. |
fd7d5287 | 411 | */ |
a5a0809b | 412 | sg_cpu->iowait_boost >>= 1; |
9eca544b | 413 | if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) { |
a5a0809b | 414 | sg_cpu->iowait_boost = 0; |
a23314e9 | 415 | return util; |
a5a0809b JF |
416 | } |
417 | } | |
418 | ||
a23314e9 PZ |
419 | sg_cpu->iowait_boost_pending = false; |
420 | ||
fd7d5287 | 421 | /* |
a23314e9 PZ |
422 | * @util is already in capacity scale; convert iowait_boost |
423 | * into the same scale so we can compare. | |
fd7d5287 | 424 | */ |
a23314e9 PZ |
425 | boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT; |
426 | return max(boost, util); | |
21ca6d2c RW |
427 | } |
428 | ||
b7eaf1aa RW |
429 | #ifdef CONFIG_NO_HZ_COMMON |
430 | static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) | |
431 | { | |
466a2b42 | 432 | unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu); |
b7eaf1aa RW |
433 | bool ret = idle_calls == sg_cpu->saved_idle_calls; |
434 | ||
435 | sg_cpu->saved_idle_calls = idle_calls; | |
436 | return ret; | |
437 | } | |
438 | #else | |
439 | static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } | |
440 | #endif /* CONFIG_NO_HZ_COMMON */ | |
441 | ||
e97a90f7 CS |
442 | /* |
443 | * Make sugov_should_update_freq() ignore the rate limit when DL | |
444 | * has increased the utilization. | |
445 | */ | |
446 | static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy) | |
447 | { | |
8cc90515 | 448 | if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) |
600f5bad | 449 | sg_policy->limits_changed = true; |
e97a90f7 CS |
450 | } |
451 | ||
9bdcb44e | 452 | static void sugov_update_single(struct update_util_data *hook, u64 time, |
58919e83 | 453 | unsigned int flags) |
9bdcb44e RW |
454 | { |
455 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
456 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
58919e83 | 457 | unsigned long util, max; |
9bdcb44e | 458 | unsigned int next_f; |
b7eaf1aa | 459 | bool busy; |
9bdcb44e | 460 | |
fd7d5287 | 461 | sugov_iowait_boost(sg_cpu, time, flags); |
21ca6d2c RW |
462 | sg_cpu->last_update = time; |
463 | ||
e97a90f7 CS |
464 | ignore_dl_rate_limit(sg_cpu, sg_policy); |
465 | ||
9bdcb44e RW |
466 | if (!sugov_should_update_freq(sg_policy, time)) |
467 | return; | |
468 | ||
600f5bad VK |
469 | /* Limits may have changed, don't skip frequency update */ |
470 | busy = !sg_policy->need_freq_update && sugov_cpu_is_busy(sg_cpu); | |
b7eaf1aa | 471 | |
dfa444dc | 472 | util = sugov_get_util(sg_cpu); |
8f111bc3 | 473 | max = sg_cpu->max; |
a23314e9 | 474 | util = sugov_iowait_apply(sg_cpu, time, util, max); |
8f111bc3 PZ |
475 | next_f = get_next_freq(sg_policy, util, max); |
476 | /* | |
477 | * Do not reduce the frequency if the CPU has not been idle | |
478 | * recently, as the reduction is likely to be premature then. | |
479 | */ | |
ecd28842 | 480 | if (busy && next_f < sg_policy->next_freq) { |
8f111bc3 | 481 | next_f = sg_policy->next_freq; |
07458f6a | 482 | |
8f111bc3 PZ |
483 | /* Reset cached freq as next_freq has changed */ |
484 | sg_policy->cached_raw_freq = 0; | |
58919e83 | 485 | } |
8f111bc3 | 486 | |
a61dec74 RW |
487 | /* |
488 | * This code runs under rq->lock for the target CPU, so it won't run | |
489 | * concurrently on two different CPUs for the same target and it is not | |
490 | * necessary to acquire the lock in the fast switch case. | |
491 | */ | |
492 | if (sg_policy->policy->fast_switch_enabled) { | |
493 | sugov_fast_switch(sg_policy, time, next_f); | |
494 | } else { | |
495 | raw_spin_lock(&sg_policy->update_lock); | |
496 | sugov_deferred_update(sg_policy, time, next_f); | |
497 | raw_spin_unlock(&sg_policy->update_lock); | |
498 | } | |
9bdcb44e RW |
499 | } |
500 | ||
d86ab9cf | 501 | static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) |
9bdcb44e | 502 | { |
5cbea469 | 503 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
9bdcb44e | 504 | struct cpufreq_policy *policy = sg_policy->policy; |
cba1dfb5 | 505 | unsigned long util = 0, max = 1; |
9bdcb44e RW |
506 | unsigned int j; |
507 | ||
9bdcb44e | 508 | for_each_cpu(j, policy->cpus) { |
cba1dfb5 | 509 | struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); |
9bdcb44e | 510 | unsigned long j_util, j_max; |
9bdcb44e | 511 | |
dfa444dc | 512 | j_util = sugov_get_util(j_sg_cpu); |
9bdcb44e | 513 | j_max = j_sg_cpu->max; |
a23314e9 | 514 | j_util = sugov_iowait_apply(j_sg_cpu, time, j_util, j_max); |
fd7d5287 | 515 | |
9bdcb44e RW |
516 | if (j_util * max > j_max * util) { |
517 | util = j_util; | |
518 | max = j_max; | |
519 | } | |
520 | } | |
521 | ||
655cb1eb | 522 | return get_next_freq(sg_policy, util, max); |
9bdcb44e RW |
523 | } |
524 | ||
97fb7a0a IM |
525 | static void |
526 | sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags) | |
9bdcb44e RW |
527 | { |
528 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
529 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
530 | unsigned int next_f; | |
531 | ||
532 | raw_spin_lock(&sg_policy->update_lock); | |
533 | ||
fd7d5287 | 534 | sugov_iowait_boost(sg_cpu, time, flags); |
9bdcb44e RW |
535 | sg_cpu->last_update = time; |
536 | ||
e97a90f7 | 537 | ignore_dl_rate_limit(sg_cpu, sg_policy); |
cba1dfb5 | 538 | |
9bdcb44e | 539 | if (sugov_should_update_freq(sg_policy, time)) { |
8f111bc3 | 540 | next_f = sugov_next_freq_shared(sg_cpu, time); |
a61dec74 RW |
541 | |
542 | if (sg_policy->policy->fast_switch_enabled) | |
543 | sugov_fast_switch(sg_policy, time, next_f); | |
544 | else | |
545 | sugov_deferred_update(sg_policy, time, next_f); | |
9bdcb44e RW |
546 | } |
547 | ||
548 | raw_spin_unlock(&sg_policy->update_lock); | |
549 | } | |
550 | ||
02a7b1ee | 551 | static void sugov_work(struct kthread_work *work) |
9bdcb44e RW |
552 | { |
553 | struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work); | |
152db033 JFG |
554 | unsigned int freq; |
555 | unsigned long flags; | |
556 | ||
557 | /* | |
558 | * Hold sg_policy->update_lock shortly to handle the case where: | |
559 | * incase sg_policy->next_freq is read here, and then updated by | |
a61dec74 | 560 | * sugov_deferred_update() just before work_in_progress is set to false |
152db033 JFG |
561 | * here, we may miss queueing the new update. |
562 | * | |
563 | * Note: If a work was queued after the update_lock is released, | |
a61dec74 | 564 | * sugov_work() will just be called again by kthread_work code; and the |
152db033 JFG |
565 | * request will be proceed before the sugov thread sleeps. |
566 | */ | |
567 | raw_spin_lock_irqsave(&sg_policy->update_lock, flags); | |
568 | freq = sg_policy->next_freq; | |
569 | sg_policy->work_in_progress = false; | |
570 | raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags); | |
9bdcb44e RW |
571 | |
572 | mutex_lock(&sg_policy->work_lock); | |
152db033 | 573 | __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L); |
9bdcb44e | 574 | mutex_unlock(&sg_policy->work_lock); |
9bdcb44e RW |
575 | } |
576 | ||
577 | static void sugov_irq_work(struct irq_work *irq_work) | |
578 | { | |
579 | struct sugov_policy *sg_policy; | |
580 | ||
581 | sg_policy = container_of(irq_work, struct sugov_policy, irq_work); | |
02a7b1ee | 582 | |
02a7b1ee | 583 | kthread_queue_work(&sg_policy->worker, &sg_policy->work); |
9bdcb44e RW |
584 | } |
585 | ||
586 | /************************** sysfs interface ************************/ | |
587 | ||
588 | static struct sugov_tunables *global_tunables; | |
589 | static DEFINE_MUTEX(global_tunables_lock); | |
590 | ||
591 | static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set) | |
592 | { | |
593 | return container_of(attr_set, struct sugov_tunables, attr_set); | |
594 | } | |
595 | ||
596 | static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) | |
597 | { | |
598 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
599 | ||
600 | return sprintf(buf, "%u\n", tunables->rate_limit_us); | |
601 | } | |
602 | ||
97fb7a0a IM |
603 | static ssize_t |
604 | rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count) | |
9bdcb44e RW |
605 | { |
606 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
607 | struct sugov_policy *sg_policy; | |
608 | unsigned int rate_limit_us; | |
609 | ||
610 | if (kstrtouint(buf, 10, &rate_limit_us)) | |
611 | return -EINVAL; | |
612 | ||
613 | tunables->rate_limit_us = rate_limit_us; | |
614 | ||
615 | list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) | |
616 | sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC; | |
617 | ||
618 | return count; | |
619 | } | |
620 | ||
621 | static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us); | |
622 | ||
9782adeb | 623 | static struct attribute *sugov_attrs[] = { |
9bdcb44e RW |
624 | &rate_limit_us.attr, |
625 | NULL | |
626 | }; | |
9782adeb | 627 | ATTRIBUTE_GROUPS(sugov); |
9bdcb44e RW |
628 | |
629 | static struct kobj_type sugov_tunables_ktype = { | |
9782adeb | 630 | .default_groups = sugov_groups, |
9bdcb44e RW |
631 | .sysfs_ops = &governor_sysfs_ops, |
632 | }; | |
633 | ||
634 | /********************** cpufreq governor interface *********************/ | |
635 | ||
531b5c9f | 636 | struct cpufreq_governor schedutil_gov; |
9bdcb44e RW |
637 | |
638 | static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) | |
639 | { | |
640 | struct sugov_policy *sg_policy; | |
641 | ||
642 | sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL); | |
643 | if (!sg_policy) | |
644 | return NULL; | |
645 | ||
646 | sg_policy->policy = policy; | |
9bdcb44e RW |
647 | raw_spin_lock_init(&sg_policy->update_lock); |
648 | return sg_policy; | |
649 | } | |
650 | ||
651 | static void sugov_policy_free(struct sugov_policy *sg_policy) | |
652 | { | |
9bdcb44e RW |
653 | kfree(sg_policy); |
654 | } | |
655 | ||
02a7b1ee VK |
656 | static int sugov_kthread_create(struct sugov_policy *sg_policy) |
657 | { | |
658 | struct task_struct *thread; | |
794a56eb | 659 | struct sched_attr attr = { |
97fb7a0a IM |
660 | .size = sizeof(struct sched_attr), |
661 | .sched_policy = SCHED_DEADLINE, | |
662 | .sched_flags = SCHED_FLAG_SUGOV, | |
663 | .sched_nice = 0, | |
664 | .sched_priority = 0, | |
794a56eb JL |
665 | /* |
666 | * Fake (unused) bandwidth; workaround to "fix" | |
667 | * priority inheritance. | |
668 | */ | |
669 | .sched_runtime = 1000000, | |
670 | .sched_deadline = 10000000, | |
671 | .sched_period = 10000000, | |
672 | }; | |
02a7b1ee VK |
673 | struct cpufreq_policy *policy = sg_policy->policy; |
674 | int ret; | |
675 | ||
676 | /* kthread only required for slow path */ | |
677 | if (policy->fast_switch_enabled) | |
678 | return 0; | |
679 | ||
680 | kthread_init_work(&sg_policy->work, sugov_work); | |
681 | kthread_init_worker(&sg_policy->worker); | |
682 | thread = kthread_create(kthread_worker_fn, &sg_policy->worker, | |
683 | "sugov:%d", | |
684 | cpumask_first(policy->related_cpus)); | |
685 | if (IS_ERR(thread)) { | |
686 | pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread)); | |
687 | return PTR_ERR(thread); | |
688 | } | |
689 | ||
794a56eb | 690 | ret = sched_setattr_nocheck(thread, &attr); |
02a7b1ee VK |
691 | if (ret) { |
692 | kthread_stop(thread); | |
794a56eb | 693 | pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); |
02a7b1ee VK |
694 | return ret; |
695 | } | |
696 | ||
697 | sg_policy->thread = thread; | |
1b04722c | 698 | kthread_bind_mask(thread, policy->related_cpus); |
21ef5729 VK |
699 | init_irq_work(&sg_policy->irq_work, sugov_irq_work); |
700 | mutex_init(&sg_policy->work_lock); | |
701 | ||
02a7b1ee VK |
702 | wake_up_process(thread); |
703 | ||
704 | return 0; | |
705 | } | |
706 | ||
707 | static void sugov_kthread_stop(struct sugov_policy *sg_policy) | |
708 | { | |
709 | /* kthread only required for slow path */ | |
710 | if (sg_policy->policy->fast_switch_enabled) | |
711 | return; | |
712 | ||
713 | kthread_flush_worker(&sg_policy->worker); | |
714 | kthread_stop(sg_policy->thread); | |
21ef5729 | 715 | mutex_destroy(&sg_policy->work_lock); |
02a7b1ee VK |
716 | } |
717 | ||
9bdcb44e RW |
718 | static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy) |
719 | { | |
720 | struct sugov_tunables *tunables; | |
721 | ||
722 | tunables = kzalloc(sizeof(*tunables), GFP_KERNEL); | |
723 | if (tunables) { | |
724 | gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook); | |
725 | if (!have_governor_per_policy()) | |
726 | global_tunables = tunables; | |
727 | } | |
728 | return tunables; | |
729 | } | |
730 | ||
731 | static void sugov_tunables_free(struct sugov_tunables *tunables) | |
732 | { | |
733 | if (!have_governor_per_policy()) | |
734 | global_tunables = NULL; | |
735 | ||
736 | kfree(tunables); | |
737 | } | |
738 | ||
739 | static int sugov_init(struct cpufreq_policy *policy) | |
740 | { | |
741 | struct sugov_policy *sg_policy; | |
742 | struct sugov_tunables *tunables; | |
9bdcb44e RW |
743 | int ret = 0; |
744 | ||
745 | /* State should be equivalent to EXIT */ | |
746 | if (policy->governor_data) | |
747 | return -EBUSY; | |
748 | ||
4a71ce43 VK |
749 | cpufreq_enable_fast_switch(policy); |
750 | ||
9bdcb44e | 751 | sg_policy = sugov_policy_alloc(policy); |
4a71ce43 VK |
752 | if (!sg_policy) { |
753 | ret = -ENOMEM; | |
754 | goto disable_fast_switch; | |
755 | } | |
9bdcb44e | 756 | |
02a7b1ee VK |
757 | ret = sugov_kthread_create(sg_policy); |
758 | if (ret) | |
759 | goto free_sg_policy; | |
760 | ||
9bdcb44e RW |
761 | mutex_lock(&global_tunables_lock); |
762 | ||
763 | if (global_tunables) { | |
764 | if (WARN_ON(have_governor_per_policy())) { | |
765 | ret = -EINVAL; | |
02a7b1ee | 766 | goto stop_kthread; |
9bdcb44e RW |
767 | } |
768 | policy->governor_data = sg_policy; | |
769 | sg_policy->tunables = global_tunables; | |
770 | ||
771 | gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook); | |
772 | goto out; | |
773 | } | |
774 | ||
775 | tunables = sugov_tunables_alloc(sg_policy); | |
776 | if (!tunables) { | |
777 | ret = -ENOMEM; | |
02a7b1ee | 778 | goto stop_kthread; |
9bdcb44e RW |
779 | } |
780 | ||
aa7519af | 781 | tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy); |
9bdcb44e RW |
782 | |
783 | policy->governor_data = sg_policy; | |
784 | sg_policy->tunables = tunables; | |
785 | ||
786 | ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype, | |
787 | get_governor_parent_kobj(policy), "%s", | |
788 | schedutil_gov.name); | |
789 | if (ret) | |
790 | goto fail; | |
791 | ||
8e2ddb03 | 792 | out: |
9bdcb44e | 793 | mutex_unlock(&global_tunables_lock); |
9bdcb44e RW |
794 | return 0; |
795 | ||
8e2ddb03 | 796 | fail: |
9a4f26cc | 797 | kobject_put(&tunables->attr_set.kobj); |
9bdcb44e RW |
798 | policy->governor_data = NULL; |
799 | sugov_tunables_free(tunables); | |
800 | ||
02a7b1ee VK |
801 | stop_kthread: |
802 | sugov_kthread_stop(sg_policy); | |
9bdcb44e RW |
803 | mutex_unlock(&global_tunables_lock); |
804 | ||
1b5d43cf | 805 | free_sg_policy: |
9bdcb44e | 806 | sugov_policy_free(sg_policy); |
4a71ce43 VK |
807 | |
808 | disable_fast_switch: | |
809 | cpufreq_disable_fast_switch(policy); | |
810 | ||
60f05e86 | 811 | pr_err("initialization failed (error %d)\n", ret); |
9bdcb44e RW |
812 | return ret; |
813 | } | |
814 | ||
e788892b | 815 | static void sugov_exit(struct cpufreq_policy *policy) |
9bdcb44e RW |
816 | { |
817 | struct sugov_policy *sg_policy = policy->governor_data; | |
818 | struct sugov_tunables *tunables = sg_policy->tunables; | |
819 | unsigned int count; | |
820 | ||
821 | mutex_lock(&global_tunables_lock); | |
822 | ||
823 | count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); | |
824 | policy->governor_data = NULL; | |
825 | if (!count) | |
826 | sugov_tunables_free(tunables); | |
827 | ||
828 | mutex_unlock(&global_tunables_lock); | |
829 | ||
02a7b1ee | 830 | sugov_kthread_stop(sg_policy); |
9bdcb44e | 831 | sugov_policy_free(sg_policy); |
4a71ce43 | 832 | cpufreq_disable_fast_switch(policy); |
9bdcb44e RW |
833 | } |
834 | ||
835 | static int sugov_start(struct cpufreq_policy *policy) | |
836 | { | |
837 | struct sugov_policy *sg_policy = policy->governor_data; | |
838 | unsigned int cpu; | |
839 | ||
97fb7a0a IM |
840 | sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; |
841 | sg_policy->last_freq_update_time = 0; | |
ecd28842 | 842 | sg_policy->next_freq = 0; |
97fb7a0a | 843 | sg_policy->work_in_progress = false; |
600f5bad | 844 | sg_policy->limits_changed = false; |
97fb7a0a IM |
845 | sg_policy->need_freq_update = false; |
846 | sg_policy->cached_raw_freq = 0; | |
9bdcb44e RW |
847 | |
848 | for_each_cpu(cpu, policy->cpus) { | |
849 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
850 | ||
4296f23e | 851 | memset(sg_cpu, 0, sizeof(*sg_cpu)); |
97fb7a0a IM |
852 | sg_cpu->cpu = cpu; |
853 | sg_cpu->sg_policy = sg_policy; | |
ab2f7cf1 VM |
854 | } |
855 | ||
856 | for_each_cpu(cpu, policy->cpus) { | |
857 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
858 | ||
4296f23e RW |
859 | cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, |
860 | policy_is_shared(policy) ? | |
861 | sugov_update_shared : | |
862 | sugov_update_single); | |
9bdcb44e RW |
863 | } |
864 | return 0; | |
865 | } | |
866 | ||
e788892b | 867 | static void sugov_stop(struct cpufreq_policy *policy) |
9bdcb44e RW |
868 | { |
869 | struct sugov_policy *sg_policy = policy->governor_data; | |
870 | unsigned int cpu; | |
871 | ||
872 | for_each_cpu(cpu, policy->cpus) | |
873 | cpufreq_remove_update_util_hook(cpu); | |
874 | ||
b290ebcf | 875 | synchronize_rcu(); |
9bdcb44e | 876 | |
21ef5729 VK |
877 | if (!policy->fast_switch_enabled) { |
878 | irq_work_sync(&sg_policy->irq_work); | |
879 | kthread_cancel_work_sync(&sg_policy->work); | |
880 | } | |
9bdcb44e RW |
881 | } |
882 | ||
e788892b | 883 | static void sugov_limits(struct cpufreq_policy *policy) |
9bdcb44e RW |
884 | { |
885 | struct sugov_policy *sg_policy = policy->governor_data; | |
886 | ||
887 | if (!policy->fast_switch_enabled) { | |
888 | mutex_lock(&sg_policy->work_lock); | |
bf2be2de | 889 | cpufreq_policy_apply_limits(policy); |
9bdcb44e RW |
890 | mutex_unlock(&sg_policy->work_lock); |
891 | } | |
892 | ||
600f5bad | 893 | sg_policy->limits_changed = true; |
9bdcb44e RW |
894 | } |
895 | ||
531b5c9f | 896 | struct cpufreq_governor schedutil_gov = { |
97fb7a0a IM |
897 | .name = "schedutil", |
898 | .owner = THIS_MODULE, | |
899 | .dynamic_switching = true, | |
900 | .init = sugov_init, | |
901 | .exit = sugov_exit, | |
902 | .start = sugov_start, | |
903 | .stop = sugov_stop, | |
904 | .limits = sugov_limits, | |
9bdcb44e RW |
905 | }; |
906 | ||
9bdcb44e RW |
907 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL |
908 | struct cpufreq_governor *cpufreq_default_governor(void) | |
909 | { | |
910 | return &schedutil_gov; | |
911 | } | |
9bdcb44e | 912 | #endif |
58919e83 RW |
913 | |
914 | static int __init sugov_register(void) | |
915 | { | |
916 | return cpufreq_register_governor(&schedutil_gov); | |
917 | } | |
918 | fs_initcall(sugov_register); | |
531b5c9f QP |
919 | |
920 | #ifdef CONFIG_ENERGY_MODEL | |
921 | extern bool sched_energy_update; | |
922 | extern struct mutex sched_energy_mutex; | |
923 | ||
924 | static void rebuild_sd_workfn(struct work_struct *work) | |
925 | { | |
926 | mutex_lock(&sched_energy_mutex); | |
927 | sched_energy_update = true; | |
928 | rebuild_sched_domains(); | |
929 | sched_energy_update = false; | |
930 | mutex_unlock(&sched_energy_mutex); | |
931 | } | |
932 | static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); | |
933 | ||
934 | /* | |
935 | * EAS shouldn't be attempted without sugov, so rebuild the sched_domains | |
936 | * on governor changes to make sure the scheduler knows about it. | |
937 | */ | |
938 | void sched_cpufreq_governor_change(struct cpufreq_policy *policy, | |
939 | struct cpufreq_governor *old_gov) | |
940 | { | |
941 | if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) { | |
942 | /* | |
943 | * When called from the cpufreq_register_driver() path, the | |
944 | * cpu_hotplug_lock is already held, so use a work item to | |
945 | * avoid nested locking in rebuild_sched_domains(). | |
946 | */ | |
947 | schedule_work(&rebuild_sd_work); | |
948 | } | |
949 | ||
950 | } | |
951 | #endif |