Commit | Line | Data |
---|---|---|
b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6bfd6d72 | 2 | /* |
81de6572 | 3 | * kernel/sched/cpudeadline.c |
6bfd6d72 JL |
4 | * |
5 | * Global CPU deadline management | |
6 | * | |
7 | * Author: Juri Lelli <j.lelli@sssup.it> | |
6bfd6d72 | 8 | */ |
6bfd6d72 JL |
9 | |
10 | static inline int parent(int i) | |
11 | { | |
12 | return (i - 1) >> 1; | |
13 | } | |
14 | ||
15 | static inline int left_child(int i) | |
16 | { | |
17 | return (i << 1) + 1; | |
18 | } | |
19 | ||
20 | static inline int right_child(int i) | |
21 | { | |
22 | return (i << 1) + 2; | |
23 | } | |
24 | ||
126b3b68 | 25 | static void cpudl_heapify_down(struct cpudl *cp, int idx) |
6bfd6d72 JL |
26 | { |
27 | int l, r, largest; | |
28 | ||
8e1bc301 TC |
29 | int orig_cpu = cp->elements[idx].cpu; |
30 | u64 orig_dl = cp->elements[idx].dl; | |
31 | ||
32 | if (left_child(idx) >= cp->size) | |
33 | return; | |
34 | ||
6bfd6d72 | 35 | /* adapted from lib/prio_heap.c */ |
c2e51382 | 36 | while (1) { |
8e1bc301 | 37 | u64 largest_dl; |
c2e51382 | 38 | |
6bfd6d72 JL |
39 | l = left_child(idx); |
40 | r = right_child(idx); | |
41 | largest = idx; | |
8e1bc301 | 42 | largest_dl = orig_dl; |
6bfd6d72 | 43 | |
8e1bc301 TC |
44 | if ((l < cp->size) && dl_time_before(orig_dl, |
45 | cp->elements[l].dl)) { | |
6bfd6d72 | 46 | largest = l; |
8e1bc301 TC |
47 | largest_dl = cp->elements[l].dl; |
48 | } | |
49 | if ((r < cp->size) && dl_time_before(largest_dl, | |
50 | cp->elements[r].dl)) | |
6bfd6d72 | 51 | largest = r; |
8e1bc301 | 52 | |
6bfd6d72 JL |
53 | if (largest == idx) |
54 | break; | |
55 | ||
8e1bc301 TC |
56 | /* pull largest child onto idx */ |
57 | cp->elements[idx].cpu = cp->elements[largest].cpu; | |
58 | cp->elements[idx].dl = cp->elements[largest].dl; | |
59 | cp->elements[cp->elements[idx].cpu].idx = idx; | |
6bfd6d72 JL |
60 | idx = largest; |
61 | } | |
8e1bc301 TC |
62 | /* actual push down of saved original values orig_* */ |
63 | cp->elements[idx].cpu = orig_cpu; | |
64 | cp->elements[idx].dl = orig_dl; | |
65 | cp->elements[cp->elements[idx].cpu].idx = idx; | |
6bfd6d72 JL |
66 | } |
67 | ||
126b3b68 | 68 | static void cpudl_heapify_up(struct cpudl *cp, int idx) |
6bfd6d72 | 69 | { |
8e1bc301 TC |
70 | int p; |
71 | ||
72 | int orig_cpu = cp->elements[idx].cpu; | |
73 | u64 orig_dl = cp->elements[idx].dl; | |
74 | ||
75 | if (idx == 0) | |
76 | return; | |
77 | ||
78 | do { | |
79 | p = parent(idx); | |
80 | if (dl_time_before(orig_dl, cp->elements[p].dl)) | |
81 | break; | |
82 | /* pull parent onto idx */ | |
83 | cp->elements[idx].cpu = cp->elements[p].cpu; | |
84 | cp->elements[idx].dl = cp->elements[p].dl; | |
85 | cp->elements[cp->elements[idx].cpu].idx = idx; | |
86 | idx = p; | |
87 | } while (idx != 0); | |
88 | /* actual push up of saved original values orig_* */ | |
89 | cp->elements[idx].cpu = orig_cpu; | |
90 | cp->elements[idx].dl = orig_dl; | |
91 | cp->elements[cp->elements[idx].cpu].idx = idx; | |
6bfd6d72 JL |
92 | } |
93 | ||
126b3b68 TC |
94 | static void cpudl_heapify(struct cpudl *cp, int idx) |
95 | { | |
96 | if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl, | |
97 | cp->elements[idx].dl)) | |
98 | cpudl_heapify_up(cp, idx); | |
99 | else | |
100 | cpudl_heapify_down(cp, idx); | |
101 | } | |
102 | ||
6bfd6d72 JL |
103 | static inline int cpudl_maximum(struct cpudl *cp) |
104 | { | |
105 | return cp->elements[0].cpu; | |
106 | } | |
107 | ||
108 | /* | |
109 | * cpudl_find - find the best (later-dl) CPU in the system | |
110 | * @cp: the cpudl max-heap context | |
111 | * @p: the task | |
112 | * @later_mask: a mask to fill in with the selected CPUs (or NULL) | |
113 | * | |
3261ed0b | 114 | * Returns: int - CPUs were found |
6bfd6d72 JL |
115 | */ |
116 | int cpudl_find(struct cpudl *cp, struct task_struct *p, | |
117 | struct cpumask *later_mask) | |
118 | { | |
6bfd6d72 JL |
119 | const struct sched_dl_entity *dl_se = &p->dl; |
120 | ||
16b26943 | 121 | if (later_mask && |
95158a89 | 122 | cpumask_and(later_mask, cp->free_cpus, &p->cpus_mask)) { |
23e71d8b LA |
123 | unsigned long cap, max_cap = 0; |
124 | int cpu, max_cpu = -1; | |
b4118988 | 125 | |
740cf8a7 | 126 | if (!sched_asym_cpucap_active()) |
b4118988 LA |
127 | return 1; |
128 | ||
129 | /* Ensure the capacity of the CPUs fits the task. */ | |
130 | for_each_cpu(cpu, later_mask) { | |
23e71d8b | 131 | if (!dl_task_fits_capacity(p, cpu)) { |
b4118988 | 132 | cpumask_clear_cpu(cpu, later_mask); |
23e71d8b LA |
133 | |
134 | cap = capacity_orig_of(cpu); | |
135 | ||
136 | if (cap > max_cap || | |
137 | (cpu == task_cpu(p) && cap == max_cap)) { | |
138 | max_cap = cap; | |
139 | max_cpu = cpu; | |
140 | } | |
141 | } | |
b4118988 LA |
142 | } |
143 | ||
23e71d8b LA |
144 | if (cpumask_empty(later_mask)) |
145 | cpumask_set_cpu(max_cpu, later_mask); | |
146 | ||
147 | return 1; | |
3261ed0b BP |
148 | } else { |
149 | int best_cpu = cpudl_maximum(cp); | |
c2e51382 | 150 | |
3261ed0b | 151 | WARN_ON(best_cpu != -1 && !cpu_present(best_cpu)); |
6bfd6d72 | 152 | |
95158a89 | 153 | if (cpumask_test_cpu(best_cpu, &p->cpus_mask) && |
3261ed0b BP |
154 | dl_time_before(dl_se->deadline, cp->elements[0].dl)) { |
155 | if (later_mask) | |
156 | cpumask_set_cpu(best_cpu, later_mask); | |
6bfd6d72 | 157 | |
3261ed0b BP |
158 | return 1; |
159 | } | |
160 | } | |
161 | return 0; | |
6bfd6d72 JL |
162 | } |
163 | ||
164 | /* | |
97fb7a0a | 165 | * cpudl_clear - remove a CPU from the cpudl max-heap |
6bfd6d72 | 166 | * @cp: the cpudl max-heap context |
97fb7a0a | 167 | * @cpu: the target CPU |
6bfd6d72 JL |
168 | * |
169 | * Notes: assumes cpu_rq(cpu)->lock is locked | |
170 | * | |
171 | * Returns: (void) | |
172 | */ | |
d8206bb3 | 173 | void cpudl_clear(struct cpudl *cp, int cpu) |
6bfd6d72 JL |
174 | { |
175 | int old_idx, new_cpu; | |
176 | unsigned long flags; | |
177 | ||
82b95800 | 178 | WARN_ON(!cpu_present(cpu)); |
6bfd6d72 JL |
179 | |
180 | raw_spin_lock_irqsave(&cp->lock, flags); | |
d8206bb3 | 181 | |
944770ab | 182 | old_idx = cp->elements[cpu].idx; |
d8206bb3 TC |
183 | if (old_idx == IDX_INVALID) { |
184 | /* | |
185 | * Nothing to remove if old_idx was invalid. | |
186 | * This could happen if a rq_offline_dl is | |
187 | * called for a CPU without -dl tasks running. | |
188 | */ | |
189 | } else { | |
6bfd6d72 JL |
190 | new_cpu = cp->elements[cp->size - 1].cpu; |
191 | cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl; | |
192 | cp->elements[old_idx].cpu = new_cpu; | |
193 | cp->size--; | |
944770ab PZ |
194 | cp->elements[new_cpu].idx = old_idx; |
195 | cp->elements[cpu].idx = IDX_INVALID; | |
126b3b68 | 196 | cpudl_heapify(cp, old_idx); |
6bfd6d72 | 197 | |
d8206bb3 | 198 | cpumask_set_cpu(cpu, cp->free_cpus); |
6bfd6d72 | 199 | } |
d8206bb3 TC |
200 | raw_spin_unlock_irqrestore(&cp->lock, flags); |
201 | } | |
202 | ||
203 | /* | |
204 | * cpudl_set - update the cpudl max-heap | |
205 | * @cp: the cpudl max-heap context | |
97fb7a0a IM |
206 | * @cpu: the target CPU |
207 | * @dl: the new earliest deadline for this CPU | |
d8206bb3 TC |
208 | * |
209 | * Notes: assumes cpu_rq(cpu)->lock is locked | |
210 | * | |
211 | * Returns: (void) | |
212 | */ | |
213 | void cpudl_set(struct cpudl *cp, int cpu, u64 dl) | |
214 | { | |
215 | int old_idx; | |
216 | unsigned long flags; | |
217 | ||
218 | WARN_ON(!cpu_present(cpu)); | |
6bfd6d72 | 219 | |
d8206bb3 TC |
220 | raw_spin_lock_irqsave(&cp->lock, flags); |
221 | ||
222 | old_idx = cp->elements[cpu].idx; | |
6bfd6d72 | 223 | if (old_idx == IDX_INVALID) { |
126b3b68 | 224 | int new_idx = cp->size++; |
c2e51382 | 225 | |
126b3b68 TC |
226 | cp->elements[new_idx].dl = dl; |
227 | cp->elements[new_idx].cpu = cpu; | |
228 | cp->elements[cpu].idx = new_idx; | |
229 | cpudl_heapify_up(cp, new_idx); | |
6bfd6d72 JL |
230 | cpumask_clear_cpu(cpu, cp->free_cpus); |
231 | } else { | |
126b3b68 TC |
232 | cp->elements[old_idx].dl = dl; |
233 | cpudl_heapify(cp, old_idx); | |
6bfd6d72 JL |
234 | } |
235 | ||
6bfd6d72 JL |
236 | raw_spin_unlock_irqrestore(&cp->lock, flags); |
237 | } | |
238 | ||
16b26943 XP |
239 | /* |
240 | * cpudl_set_freecpu - Set the cpudl.free_cpus | |
241 | * @cp: the cpudl max-heap context | |
97fb7a0a | 242 | * @cpu: rd attached CPU |
16b26943 XP |
243 | */ |
244 | void cpudl_set_freecpu(struct cpudl *cp, int cpu) | |
245 | { | |
246 | cpumask_set_cpu(cpu, cp->free_cpus); | |
247 | } | |
248 | ||
249 | /* | |
250 | * cpudl_clear_freecpu - Clear the cpudl.free_cpus | |
251 | * @cp: the cpudl max-heap context | |
97fb7a0a | 252 | * @cpu: rd attached CPU |
16b26943 XP |
253 | */ |
254 | void cpudl_clear_freecpu(struct cpudl *cp, int cpu) | |
255 | { | |
256 | cpumask_clear_cpu(cpu, cp->free_cpus); | |
257 | } | |
258 | ||
6bfd6d72 JL |
259 | /* |
260 | * cpudl_init - initialize the cpudl structure | |
261 | * @cp: the cpudl max-heap context | |
262 | */ | |
263 | int cpudl_init(struct cpudl *cp) | |
264 | { | |
265 | int i; | |
266 | ||
6bfd6d72 JL |
267 | raw_spin_lock_init(&cp->lock); |
268 | cp->size = 0; | |
944770ab PZ |
269 | |
270 | cp->elements = kcalloc(nr_cpu_ids, | |
271 | sizeof(struct cpudl_item), | |
272 | GFP_KERNEL); | |
273 | if (!cp->elements) | |
274 | return -ENOMEM; | |
275 | ||
16b26943 | 276 | if (!zalloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) { |
944770ab | 277 | kfree(cp->elements); |
6bfd6d72 | 278 | return -ENOMEM; |
944770ab PZ |
279 | } |
280 | ||
281 | for_each_possible_cpu(i) | |
282 | cp->elements[i].idx = IDX_INVALID; | |
283 | ||
6bfd6d72 JL |
284 | return 0; |
285 | } | |
286 | ||
287 | /* | |
288 | * cpudl_cleanup - clean up the cpudl structure | |
289 | * @cp: the cpudl max-heap context | |
290 | */ | |
291 | void cpudl_cleanup(struct cpudl *cp) | |
292 | { | |
6a7cd273 | 293 | free_cpumask_var(cp->free_cpus); |
944770ab | 294 | kfree(cp->elements); |
6bfd6d72 | 295 | } |