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