^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Timer events oriented CPU idle governor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2018 Intel Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * The idea of this governor is based on the observation that on many systems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * timer events are two or more orders of magnitude more frequent than any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * other interrupts, so they are likely to be the most significant source of CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * wakeups from idle states. Moreover, information about what happened in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * (relatively recent) past can be used to estimate whether or not the deepest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * idle state with target residency within the time to the closest timer is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * likely to be suitable for the upcoming idle time of the CPU and, if not, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * which of the shallower idle states to choose.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Of course, non-timer wakeup sources are more important in some use cases and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * they can be covered by taking a few most recent idle time intervals of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * CPU into account. However, even in that case it is not necessary to consider
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * idle duration values greater than the time till the closest timer, as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * patterns that they may belong to produce average values close enough to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * the time till the closest timer (sleep length) anyway.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Thus this governor estimates whether or not the upcoming idle time of the CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * is likely to be significantly shorter than the sleep length and selects an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * idle state for it in accordance with that, as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * - Find an idle state on the basis of the sleep length and state statistics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * collected over time:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * o Find the deepest idle state whose target residency is less than or equal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * to the sleep length.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * o Select it if it matched both the sleep length and the observed idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * duration in the past more often than it matched the sleep length alone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * (i.e. the observed idle duration was significantly shorter than the sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * length matched by it).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * o Otherwise, select the shallower state with the greatest matched "early"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * wakeups metric.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * - If the majority of the most recent idle duration values are below the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * target residency of the idle state selected so far, use those values to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * compute the new expected idle duration and find an idle state matching it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * (which has to be shallower than the one selected so far).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/cpuidle.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <linux/sched/clock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * The PULSE value is added to metrics when they grow and the DECAY_SHIFT value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * is used for decreasing metrics on a regular basis.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #define PULSE 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #define DECAY_SHIFT 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * Number of the most recent idle duration values to take into consideration for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * the detection of wakeup patterns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #define INTERVALS 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * struct teo_idle_state - Idle state data used by the TEO cpuidle governor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * @early_hits: "Early" CPU wakeups "matching" this state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * @hits: "On time" CPU wakeups "matching" this state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * @misses: CPU wakeups "missing" this state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * A CPU wakeup is "matched" by a given idle state if the idle duration measured
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * after the wakeup is between the target residency of that state and the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * residency of the next one (or if this is the deepest available idle state, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * "matches" a CPU wakeup when the measured idle duration is at least equal to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * its target residency).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * Also, from the TEO governor perspective, a CPU wakeup from idle is "early" if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * it occurs significantly earlier than the closest expected timer event (that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * is, early enough to match an idle state shallower than the one matching the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * time till the closest timer event). Otherwise, the wakeup is "on time", or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * it is a "hit".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * A "miss" occurs when the given state doesn't match the wakeup, but it matches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * the time till the closest timer event used for idle state selection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) struct teo_idle_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) unsigned int early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) unsigned int hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) unsigned int misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * struct teo_cpu - CPU data used by the TEO cpuidle governor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * @time_span_ns: Time between idle state selection and post-wakeup update.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * @sleep_length_ns: Time till the closest timer event (at the selection time).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * @states: Idle states data corresponding to this CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * @interval_idx: Index of the most recent saved idle interval.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * @intervals: Saved idle duration values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) struct teo_cpu {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) u64 time_span_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) u64 sleep_length_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) struct teo_idle_state states[CPUIDLE_STATE_MAX];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) int interval_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) u64 intervals[INTERVALS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) static DEFINE_PER_CPU(struct teo_cpu, teo_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * teo_update - Update CPU data after wakeup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * @drv: cpuidle driver containing state data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * @dev: Target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) int i, idx_hit = -1, idx_timer = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) u64 measured_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * One of the safety nets has triggered or the wakeup was close
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * enough to the closest timer event expected at the idle state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * selection time to be discarded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) measured_ns = U64_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) u64 lat_ns = drv->states[dev->last_state_idx].exit_latency_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * The computations below are to determine whether or not the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * (saved) time till the next timer event and the measured idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * duration fall into the same "bin", so use last_residency_ns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * for that instead of time_span_ns which includes the cpuidle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * overhead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) measured_ns = dev->last_residency_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * The delay between the wakeup and the first instruction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * executed by the CPU is not likely to be worst-case every
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * time, so take 1/2 of the exit latency as a very rough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * approximation of the average of it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) if (measured_ns >= lat_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) measured_ns -= lat_ns / 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) measured_ns /= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * Decay the "early hits" metric for all of the states and find the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * states matching the sleep length and the measured idle duration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) for (i = 0; i < drv->state_count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) unsigned int early_hits = cpu_data->states[i].early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) cpu_data->states[i].early_hits -= early_hits >> DECAY_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) if (drv->states[i].target_residency_ns <= cpu_data->sleep_length_ns) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) idx_timer = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (drv->states[i].target_residency_ns <= measured_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) idx_hit = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * Update the "hits" and "misses" data for the state matching the sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * length. If it matches the measured idle duration too, this is a hit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * so increase the "hits" metric for it then. Otherwise, this is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * miss, so increase the "misses" metric for it. In the latter case
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * also increase the "early hits" metric for the state that actually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * matches the measured idle duration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (idx_timer >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) unsigned int hits = cpu_data->states[idx_timer].hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) unsigned int misses = cpu_data->states[idx_timer].misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) hits -= hits >> DECAY_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) misses -= misses >> DECAY_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (idx_timer > idx_hit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) misses += PULSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (idx_hit >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) cpu_data->states[idx_hit].early_hits += PULSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) hits += PULSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) cpu_data->states[idx_timer].misses = misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) cpu_data->states[idx_timer].hits = hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * Save idle duration values corresponding to non-timer wakeups for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * pattern detection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) cpu_data->intervals[cpu_data->interval_idx++] = measured_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) if (cpu_data->interval_idx >= INTERVALS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) cpu_data->interval_idx = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) static bool teo_time_ok(u64 interval_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) return !tick_nohz_tick_stopped() || interval_ns >= TICK_NSEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * teo_find_shallower_state - Find shallower idle state matching given duration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) * @drv: cpuidle driver containing state data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) * @dev: Target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) * @state_idx: Index of the capping idle state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * @duration_ns: Idle duration value to match.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) static int teo_find_shallower_state(struct cpuidle_driver *drv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) struct cpuidle_device *dev, int state_idx,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) u64 duration_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) for (i = state_idx - 1; i >= 0; i--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) if (dev->states_usage[i].disable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) state_idx = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) if (drv->states[i].target_residency_ns <= duration_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) return state_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * teo_select - Selects the next idle state to enter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) * @drv: cpuidle driver containing state data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) * @dev: Target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) * @stop_tick: Indication on whether or not to stop the scheduler tick.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) bool *stop_tick)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) s64 latency_req = cpuidle_governor_latency_req(dev->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) u64 duration_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) unsigned int hits, misses, early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) int max_early_idx, prev_max_early_idx, constraint_idx, idx, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) ktime_t delta_tick;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) if (dev->last_state_idx >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) teo_update(drv, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) dev->last_state_idx = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) cpu_data->time_span_ns = local_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) duration_ns = tick_nohz_get_sleep_length(&delta_tick);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) cpu_data->sleep_length_ns = duration_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) hits = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) misses = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) early_hits = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) max_early_idx = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) prev_max_early_idx = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) constraint_idx = drv->state_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) idx = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) for (i = 0; i < drv->state_count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) struct cpuidle_state *s = &drv->states[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) if (dev->states_usage[i].disable) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * Ignore disabled states with target residencies beyond
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * the anticipated idle duration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) if (s->target_residency_ns > duration_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) * This state is disabled, so the range of idle duration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * values corresponding to it is covered by the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * candidate state, but still the "hits" and "misses"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * metrics of the disabled state need to be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * decide whether or not the state covering the range in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * question is good enough.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) hits = cpu_data->states[i].hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) misses = cpu_data->states[i].misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) if (early_hits >= cpu_data->states[i].early_hits ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) idx < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * If the current candidate state has been the one with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * the maximum "early hits" metric so far, the "early
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * hits" metric of the disabled state replaces the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * current "early hits" count to avoid selecting a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * deeper state with lower "early hits" metric.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) if (max_early_idx == idx) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) early_hits = cpu_data->states[i].early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * The current candidate state is closer to the disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) * one than the current maximum "early hits" state, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * replace the latter with it, but in case the maximum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) * "early hits" state index has not been set so far,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * check if the current candidate state is not too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * shallow for that role.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) if (teo_time_ok(drv->states[idx].target_residency_ns)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) prev_max_early_idx = max_early_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) early_hits = cpu_data->states[i].early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) max_early_idx = idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (idx < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) idx = i; /* first enabled state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) hits = cpu_data->states[i].hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) misses = cpu_data->states[i].misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (s->target_residency_ns > duration_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) if (s->exit_latency_ns > latency_req && constraint_idx > i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) constraint_idx = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) idx = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) hits = cpu_data->states[i].hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) misses = cpu_data->states[i].misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) if (early_hits < cpu_data->states[i].early_hits &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) teo_time_ok(drv->states[i].target_residency_ns)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) prev_max_early_idx = max_early_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) early_hits = cpu_data->states[i].early_hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) max_early_idx = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * If the "hits" metric of the idle state matching the sleep length is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * greater than its "misses" metric, that is the one to use. Otherwise,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) * it is more likely that one of the shallower states will match the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * idle duration observed after wakeup, so take the one with the maximum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * "early hits" metric, but if that cannot be determined, just use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * state selected so far.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) if (hits <= misses) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * The current candidate state is not suitable, so take the one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * whose "early hits" metric is the maximum for the range of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * shallower states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) if (idx == max_early_idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) max_early_idx = prev_max_early_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (max_early_idx >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) idx = max_early_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) duration_ns = drv->states[idx].target_residency_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) * If there is a latency constraint, it may be necessary to use a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) * shallower idle state than the one selected so far.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) if (constraint_idx < idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) idx = constraint_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) if (idx < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) idx = 0; /* No states enabled. Must use 0. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) } else if (idx > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) unsigned int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) u64 sum = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) * Count and sum the most recent idle duration values less than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * the current expected idle duration value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) for (i = 0; i < INTERVALS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) u64 val = cpu_data->intervals[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) if (val >= duration_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) sum += val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) * Give up unless the majority of the most recent idle duration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) * values are in the interesting range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) if (count > INTERVALS / 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) u64 avg_ns = div64_u64(sum, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * Avoid spending too much time in an idle state that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * would be too shallow.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) if (teo_time_ok(avg_ns)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) duration_ns = avg_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) if (drv->states[idx].target_residency_ns > avg_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) idx = teo_find_shallower_state(drv, dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) idx, avg_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * Don't stop the tick if the selected state is a polling one or if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * expected idle duration is shorter than the tick period length.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) if (((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) duration_ns < TICK_NSEC) && !tick_nohz_tick_stopped()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) *stop_tick = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) * The tick is not going to be stopped, so if the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) * residency of the state to be returned is not within the time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) * till the closest timer including the tick, try to correct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) * that.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (idx > 0 && drv->states[idx].target_residency_ns > delta_tick)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) idx = teo_find_shallower_state(drv, dev, idx, delta_tick);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) return idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * teo_reflect - Note that governor data for the CPU need to be updated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) * @dev: Target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * @state: Entered state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) static void teo_reflect(struct cpuidle_device *dev, int state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) dev->last_state_idx = state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * If the wakeup was not "natural", but triggered by one of the safety
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * nets, assume that the CPU might have been idle for the entire sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * length time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) if (dev->poll_time_limit ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) (tick_nohz_idle_got_tick() && cpu_data->sleep_length_ns > TICK_NSEC)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) dev->poll_time_limit = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) cpu_data->time_span_ns = cpu_data->sleep_length_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) cpu_data->time_span_ns = local_clock() - cpu_data->time_span_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) * teo_enable_device - Initialize the governor's data for the target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * @drv: cpuidle driver (not used).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * @dev: Target CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) static int teo_enable_device(struct cpuidle_driver *drv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) struct cpuidle_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) memset(cpu_data, 0, sizeof(*cpu_data));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) for (i = 0; i < INTERVALS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) cpu_data->intervals[i] = U64_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) static struct cpuidle_governor teo_governor = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) .name = "teo",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) .rating = 19,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) .enable = teo_enable_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) .select = teo_select,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) .reflect = teo_reflect,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) static int __init teo_governor_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) return cpuidle_register_governor(&teo_governor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) postcore_initcall(teo_governor_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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