xref: /linux/kernel/sched/pelt.h (revision e7cd4b811c9e019f5acbce85699c622b30194c24)
1 #ifdef CONFIG_SMP
2 #include "sched-pelt.h"
3 
4 int __update_load_avg_blocked_se(u64 now, struct sched_entity *se);
5 int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se);
6 int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
7 int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
8 int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
9 bool update_other_load_avgs(struct rq *rq);
10 
11 #ifdef CONFIG_SCHED_HW_PRESSURE
12 int update_hw_load_avg(u64 now, struct rq *rq, u64 capacity);
13 
14 static inline u64 hw_load_avg(struct rq *rq)
15 {
16 	return READ_ONCE(rq->avg_hw.load_avg);
17 }
18 #else
19 static inline int
20 update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
21 {
22 	return 0;
23 }
24 
25 static inline u64 hw_load_avg(struct rq *rq)
26 {
27 	return 0;
28 }
29 #endif
30 
31 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
32 int update_irq_load_avg(struct rq *rq, u64 running);
33 #else
34 static inline int
35 update_irq_load_avg(struct rq *rq, u64 running)
36 {
37 	return 0;
38 }
39 #endif
40 
41 #define PELT_MIN_DIVIDER	(LOAD_AVG_MAX - 1024)
42 
43 static inline u32 get_pelt_divider(struct sched_avg *avg)
44 {
45 	return PELT_MIN_DIVIDER + avg->period_contrib;
46 }
47 
48 static inline void cfs_se_util_change(struct sched_avg *avg)
49 {
50 	unsigned int enqueued;
51 
52 	if (!sched_feat(UTIL_EST))
53 		return;
54 
55 	/* Avoid store if the flag has been already reset */
56 	enqueued = avg->util_est;
57 	if (!(enqueued & UTIL_AVG_UNCHANGED))
58 		return;
59 
60 	/* Reset flag to report util_avg has been updated */
61 	enqueued &= ~UTIL_AVG_UNCHANGED;
62 	WRITE_ONCE(avg->util_est, enqueued);
63 }
64 
65 static inline u64 rq_clock_pelt(struct rq *rq)
66 {
67 	lockdep_assert_rq_held(rq);
68 	assert_clock_updated(rq);
69 
70 	return rq->clock_pelt - rq->lost_idle_time;
71 }
72 
73 /* The rq is idle, we can sync to clock_task */
74 static inline void _update_idle_rq_clock_pelt(struct rq *rq)
75 {
76 	rq->clock_pelt  = rq_clock_task(rq);
77 
78 	u64_u32_store(rq->clock_idle, rq_clock(rq));
79 	/* Paired with smp_rmb in migrate_se_pelt_lag() */
80 	smp_wmb();
81 	u64_u32_store(rq->clock_pelt_idle, rq_clock_pelt(rq));
82 }
83 
84 /*
85  * The clock_pelt scales the time to reflect the effective amount of
86  * computation done during the running delta time but then sync back to
87  * clock_task when rq is idle.
88  *
89  *
90  * absolute time   | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|13|14|15|16
91  * @ max capacity  ------******---------------******---------------
92  * @ half capacity ------************---------************---------
93  * clock pelt      | 1| 2|    3|    4| 7| 8| 9|   10|   11|14|15|16
94  *
95  */
96 static inline void update_rq_clock_pelt(struct rq *rq, s64 delta)
97 {
98 	if (unlikely(is_idle_task(rq->curr))) {
99 		_update_idle_rq_clock_pelt(rq);
100 		return;
101 	}
102 
103 	/*
104 	 * When a rq runs at a lower compute capacity, it will need
105 	 * more time to do the same amount of work than at max
106 	 * capacity. In order to be invariant, we scale the delta to
107 	 * reflect how much work has been really done.
108 	 * Running longer results in stealing idle time that will
109 	 * disturb the load signal compared to max capacity. This
110 	 * stolen idle time will be automatically reflected when the
111 	 * rq will be idle and the clock will be synced with
112 	 * rq_clock_task.
113 	 */
114 
115 	/*
116 	 * Scale the elapsed time to reflect the real amount of
117 	 * computation
118 	 */
119 	delta = cap_scale(delta, arch_scale_cpu_capacity(cpu_of(rq)));
120 	delta = cap_scale(delta, arch_scale_freq_capacity(cpu_of(rq)));
121 
122 	rq->clock_pelt += delta;
123 }
124 
125 /*
126  * When rq becomes idle, we have to check if it has lost idle time
127  * because it was fully busy. A rq is fully used when the /Sum util_sum
128  * is greater or equal to:
129  * (LOAD_AVG_MAX - 1024 + rq->cfs.avg.period_contrib) << SCHED_CAPACITY_SHIFT;
130  * For optimization and computing rounding purpose, we don't take into account
131  * the position in the current window (period_contrib) and we use the higher
132  * bound of util_sum to decide.
133  */
134 static inline void update_idle_rq_clock_pelt(struct rq *rq)
135 {
136 	u32 divider = ((LOAD_AVG_MAX - 1024) << SCHED_CAPACITY_SHIFT) - LOAD_AVG_MAX;
137 	u32 util_sum = rq->cfs.avg.util_sum;
138 	util_sum += rq->avg_rt.util_sum;
139 	util_sum += rq->avg_dl.util_sum;
140 
141 	/*
142 	 * Reflecting stolen time makes sense only if the idle
143 	 * phase would be present at max capacity. As soon as the
144 	 * utilization of a rq has reached the maximum value, it is
145 	 * considered as an always running rq without idle time to
146 	 * steal. This potential idle time is considered as lost in
147 	 * this case. We keep track of this lost idle time compare to
148 	 * rq's clock_task.
149 	 */
150 	if (util_sum >= divider)
151 		rq->lost_idle_time += rq_clock_task(rq) - rq->clock_pelt;
152 
153 	_update_idle_rq_clock_pelt(rq);
154 }
155 
156 #ifdef CONFIG_CFS_BANDWIDTH
157 static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
158 {
159 	u64 throttled;
160 
161 	if (unlikely(cfs_rq->throttle_count))
162 		throttled = U64_MAX;
163 	else
164 		throttled = cfs_rq->throttled_clock_pelt_time;
165 
166 	u64_u32_store(cfs_rq->throttled_pelt_idle, throttled);
167 }
168 
169 /* rq->task_clock normalized against any time this cfs_rq has spent throttled */
170 static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
171 {
172 	if (unlikely(cfs_rq->throttle_count))
173 		return cfs_rq->throttled_clock_pelt - cfs_rq->throttled_clock_pelt_time;
174 
175 	return rq_clock_pelt(rq_of(cfs_rq)) - cfs_rq->throttled_clock_pelt_time;
176 }
177 #else
178 static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) { }
179 static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
180 {
181 	return rq_clock_pelt(rq_of(cfs_rq));
182 }
183 #endif
184 
185 #else
186 
187 static inline int
188 update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
189 {
190 	return 0;
191 }
192 
193 static inline int
194 update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
195 {
196 	return 0;
197 }
198 
199 static inline int
200 update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
201 {
202 	return 0;
203 }
204 
205 static inline int
206 update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
207 {
208 	return 0;
209 }
210 
211 static inline u64 hw_load_avg(struct rq *rq)
212 {
213 	return 0;
214 }
215 
216 static inline int
217 update_irq_load_avg(struct rq *rq, u64 running)
218 {
219 	return 0;
220 }
221 
222 static inline u64 rq_clock_pelt(struct rq *rq)
223 {
224 	return rq_clock_task(rq);
225 }
226 
227 static inline void
228 update_rq_clock_pelt(struct rq *rq, s64 delta) { }
229 
230 static inline void
231 update_idle_rq_clock_pelt(struct rq *rq) { }
232 
233 static inline void update_idle_cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) { }
234 #endif
235 
236 
237