Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f2cb1360 IM |
2 | /* |
3 | * Scheduler topology setup/handling methods | |
4 | */ | |
f2cb1360 | 5 | |
cd7f5535 YN |
6 | #include <linux/bsearch.h> |
7 | ||
f2cb1360 IM |
8 | DEFINE_MUTEX(sched_domains_mutex); |
9 | ||
10 | /* Protected by sched_domains_mutex: */ | |
ace80310 | 11 | static cpumask_var_t sched_domains_tmpmask; |
12 | static cpumask_var_t sched_domains_tmpmask2; | |
f2cb1360 IM |
13 | |
14 | #ifdef CONFIG_SCHED_DEBUG | |
15 | ||
f2cb1360 IM |
16 | static int __init sched_debug_setup(char *str) |
17 | { | |
9406415f | 18 | sched_debug_verbose = true; |
f2cb1360 IM |
19 | |
20 | return 0; | |
21 | } | |
9406415f | 22 | early_param("sched_verbose", sched_debug_setup); |
f2cb1360 IM |
23 | |
24 | static inline bool sched_debug(void) | |
25 | { | |
9406415f | 26 | return sched_debug_verbose; |
f2cb1360 IM |
27 | } |
28 | ||
848785df VS |
29 | #define SD_FLAG(_name, mflags) [__##_name] = { .meta_flags = mflags, .name = #_name }, |
30 | const struct sd_flag_debug sd_flag_debug[] = { | |
31 | #include <linux/sched/sd_flags.h> | |
32 | }; | |
33 | #undef SD_FLAG | |
34 | ||
f2cb1360 IM |
35 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
36 | struct cpumask *groupmask) | |
37 | { | |
38 | struct sched_group *group = sd->groups; | |
65c5e253 VS |
39 | unsigned long flags = sd->flags; |
40 | unsigned int idx; | |
f2cb1360 IM |
41 | |
42 | cpumask_clear(groupmask); | |
43 | ||
005f874d | 44 | printk(KERN_DEBUG "%*s domain-%d: ", level, "", level); |
005f874d | 45 | printk(KERN_CONT "span=%*pbl level=%s\n", |
f2cb1360 IM |
46 | cpumask_pr_args(sched_domain_span(sd)), sd->name); |
47 | ||
48 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
97fb7a0a | 49 | printk(KERN_ERR "ERROR: domain->span does not contain CPU%d\n", cpu); |
f2cb1360 | 50 | } |
6cd0c583 | 51 | if (group && !cpumask_test_cpu(cpu, sched_group_span(group))) { |
97fb7a0a | 52 | printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu); |
f2cb1360 IM |
53 | } |
54 | ||
65c5e253 VS |
55 | for_each_set_bit(idx, &flags, __SD_FLAG_CNT) { |
56 | unsigned int flag = BIT(idx); | |
57 | unsigned int meta_flags = sd_flag_debug[idx].meta_flags; | |
58 | ||
59 | if ((meta_flags & SDF_SHARED_CHILD) && sd->child && | |
60 | !(sd->child->flags & flag)) | |
61 | printk(KERN_ERR "ERROR: flag %s set here but not in child\n", | |
62 | sd_flag_debug[idx].name); | |
63 | ||
64 | if ((meta_flags & SDF_SHARED_PARENT) && sd->parent && | |
65 | !(sd->parent->flags & flag)) | |
66 | printk(KERN_ERR "ERROR: flag %s set here but not in parent\n", | |
67 | sd_flag_debug[idx].name); | |
68 | } | |
69 | ||
f2cb1360 IM |
70 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
71 | do { | |
72 | if (!group) { | |
73 | printk("\n"); | |
74 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
75 | break; | |
76 | } | |
77 | ||
1087ad4e | 78 | if (cpumask_empty(sched_group_span(group))) { |
f2cb1360 IM |
79 | printk(KERN_CONT "\n"); |
80 | printk(KERN_ERR "ERROR: empty group\n"); | |
81 | break; | |
82 | } | |
83 | ||
84 | if (!(sd->flags & SD_OVERLAP) && | |
ae4df9d6 | 85 | cpumask_intersects(groupmask, sched_group_span(group))) { |
f2cb1360 IM |
86 | printk(KERN_CONT "\n"); |
87 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
88 | break; | |
89 | } | |
90 | ||
ae4df9d6 | 91 | cpumask_or(groupmask, groupmask, sched_group_span(group)); |
f2cb1360 | 92 | |
005f874d PZ |
93 | printk(KERN_CONT " %d:{ span=%*pbl", |
94 | group->sgc->id, | |
ae4df9d6 | 95 | cpumask_pr_args(sched_group_span(group))); |
b0151c25 | 96 | |
af218122 | 97 | if ((sd->flags & SD_OVERLAP) && |
ae4df9d6 | 98 | !cpumask_equal(group_balance_mask(group), sched_group_span(group))) { |
005f874d | 99 | printk(KERN_CONT " mask=%*pbl", |
e5c14b1f | 100 | cpumask_pr_args(group_balance_mask(group))); |
b0151c25 PZ |
101 | } |
102 | ||
005f874d PZ |
103 | if (group->sgc->capacity != SCHED_CAPACITY_SCALE) |
104 | printk(KERN_CONT " cap=%lu", group->sgc->capacity); | |
f2cb1360 | 105 | |
a420b063 PZ |
106 | if (group == sd->groups && sd->child && |
107 | !cpumask_equal(sched_domain_span(sd->child), | |
ae4df9d6 | 108 | sched_group_span(group))) { |
a420b063 PZ |
109 | printk(KERN_ERR "ERROR: domain->groups does not match domain->child\n"); |
110 | } | |
111 | ||
005f874d PZ |
112 | printk(KERN_CONT " }"); |
113 | ||
f2cb1360 | 114 | group = group->next; |
b0151c25 PZ |
115 | |
116 | if (group != sd->groups) | |
117 | printk(KERN_CONT ","); | |
118 | ||
f2cb1360 IM |
119 | } while (group != sd->groups); |
120 | printk(KERN_CONT "\n"); | |
121 | ||
122 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) | |
123 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); | |
124 | ||
125 | if (sd->parent && | |
126 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
97fb7a0a | 127 | printk(KERN_ERR "ERROR: parent span is not a superset of domain->span\n"); |
f2cb1360 IM |
128 | return 0; |
129 | } | |
130 | ||
131 | static void sched_domain_debug(struct sched_domain *sd, int cpu) | |
132 | { | |
133 | int level = 0; | |
134 | ||
9406415f | 135 | if (!sched_debug_verbose) |
f2cb1360 IM |
136 | return; |
137 | ||
138 | if (!sd) { | |
139 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
140 | return; | |
141 | } | |
142 | ||
005f874d | 143 | printk(KERN_DEBUG "CPU%d attaching sched-domain(s):\n", cpu); |
f2cb1360 IM |
144 | |
145 | for (;;) { | |
146 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) | |
147 | break; | |
148 | level++; | |
149 | sd = sd->parent; | |
150 | if (!sd) | |
151 | break; | |
152 | } | |
153 | } | |
154 | #else /* !CONFIG_SCHED_DEBUG */ | |
155 | ||
9406415f | 156 | # define sched_debug_verbose 0 |
f2cb1360 IM |
157 | # define sched_domain_debug(sd, cpu) do { } while (0) |
158 | static inline bool sched_debug(void) | |
159 | { | |
160 | return false; | |
161 | } | |
162 | #endif /* CONFIG_SCHED_DEBUG */ | |
163 | ||
4fc472f1 VS |
164 | /* Generate a mask of SD flags with the SDF_NEEDS_GROUPS metaflag */ |
165 | #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_NEEDS_GROUPS)) | | |
166 | static const unsigned int SD_DEGENERATE_GROUPS_MASK = | |
167 | #include <linux/sched/sd_flags.h> | |
168 | 0; | |
169 | #undef SD_FLAG | |
170 | ||
f2cb1360 IM |
171 | static int sd_degenerate(struct sched_domain *sd) |
172 | { | |
173 | if (cpumask_weight(sched_domain_span(sd)) == 1) | |
174 | return 1; | |
175 | ||
176 | /* Following flags need at least 2 groups */ | |
6f349818 VS |
177 | if ((sd->flags & SD_DEGENERATE_GROUPS_MASK) && |
178 | (sd->groups != sd->groups->next)) | |
179 | return 0; | |
f2cb1360 IM |
180 | |
181 | /* Following flags don't use groups */ | |
182 | if (sd->flags & (SD_WAKE_AFFINE)) | |
183 | return 0; | |
184 | ||
185 | return 1; | |
186 | } | |
187 | ||
188 | static int | |
189 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
190 | { | |
191 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
192 | ||
193 | if (sd_degenerate(parent)) | |
194 | return 1; | |
195 | ||
196 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) | |
197 | return 0; | |
198 | ||
199 | /* Flags needing groups don't count if only 1 group in parent */ | |
ab65afb0 | 200 | if (parent->groups == parent->groups->next) |
3a6712c7 | 201 | pflags &= ~SD_DEGENERATE_GROUPS_MASK; |
ab65afb0 | 202 | |
f2cb1360 IM |
203 | if (~cflags & pflags) |
204 | return 0; | |
205 | ||
206 | return 1; | |
207 | } | |
208 | ||
531b5c9f | 209 | #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) |
f8a696f2 | 210 | DEFINE_STATIC_KEY_FALSE(sched_energy_present); |
8a044141 | 211 | static unsigned int sysctl_sched_energy_aware = 1; |
531b5c9f QP |
212 | DEFINE_MUTEX(sched_energy_mutex); |
213 | bool sched_energy_update; | |
214 | ||
31f6a8c0 IV |
215 | void rebuild_sched_domains_energy(void) |
216 | { | |
217 | mutex_lock(&sched_energy_mutex); | |
218 | sched_energy_update = true; | |
219 | rebuild_sched_domains(); | |
220 | sched_energy_update = false; | |
221 | mutex_unlock(&sched_energy_mutex); | |
222 | } | |
223 | ||
8d5d0cfb | 224 | #ifdef CONFIG_PROC_SYSCTL |
8a044141 | 225 | static int sched_energy_aware_handler(struct ctl_table *table, int write, |
32927393 | 226 | void *buffer, size_t *lenp, loff_t *ppos) |
8d5d0cfb QP |
227 | { |
228 | int ret, state; | |
229 | ||
230 | if (write && !capable(CAP_SYS_ADMIN)) | |
231 | return -EPERM; | |
232 | ||
233 | ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); | |
234 | if (!ret && write) { | |
235 | state = static_branch_unlikely(&sched_energy_present); | |
31f6a8c0 IV |
236 | if (state != sysctl_sched_energy_aware) |
237 | rebuild_sched_domains_energy(); | |
8d5d0cfb QP |
238 | } |
239 | ||
240 | return ret; | |
241 | } | |
8a044141 ZN |
242 | |
243 | static struct ctl_table sched_energy_aware_sysctls[] = { | |
244 | { | |
245 | .procname = "sched_energy_aware", | |
246 | .data = &sysctl_sched_energy_aware, | |
247 | .maxlen = sizeof(unsigned int), | |
248 | .mode = 0644, | |
249 | .proc_handler = sched_energy_aware_handler, | |
250 | .extra1 = SYSCTL_ZERO, | |
251 | .extra2 = SYSCTL_ONE, | |
252 | }, | |
253 | {} | |
254 | }; | |
255 | ||
256 | static int __init sched_energy_aware_sysctl_init(void) | |
257 | { | |
258 | register_sysctl_init("kernel", sched_energy_aware_sysctls); | |
259 | return 0; | |
260 | } | |
261 | ||
262 | late_initcall(sched_energy_aware_sysctl_init); | |
8d5d0cfb QP |
263 | #endif |
264 | ||
6aa140fa QP |
265 | static void free_pd(struct perf_domain *pd) |
266 | { | |
267 | struct perf_domain *tmp; | |
268 | ||
269 | while (pd) { | |
270 | tmp = pd->next; | |
271 | kfree(pd); | |
272 | pd = tmp; | |
273 | } | |
274 | } | |
275 | ||
276 | static struct perf_domain *find_pd(struct perf_domain *pd, int cpu) | |
277 | { | |
278 | while (pd) { | |
279 | if (cpumask_test_cpu(cpu, perf_domain_span(pd))) | |
280 | return pd; | |
281 | pd = pd->next; | |
282 | } | |
283 | ||
284 | return NULL; | |
285 | } | |
286 | ||
287 | static struct perf_domain *pd_init(int cpu) | |
288 | { | |
289 | struct em_perf_domain *obj = em_cpu_get(cpu); | |
290 | struct perf_domain *pd; | |
291 | ||
292 | if (!obj) { | |
293 | if (sched_debug()) | |
294 | pr_info("%s: no EM found for CPU%d\n", __func__, cpu); | |
295 | return NULL; | |
296 | } | |
297 | ||
298 | pd = kzalloc(sizeof(*pd), GFP_KERNEL); | |
299 | if (!pd) | |
300 | return NULL; | |
301 | pd->em_pd = obj; | |
302 | ||
303 | return pd; | |
304 | } | |
305 | ||
306 | static void perf_domain_debug(const struct cpumask *cpu_map, | |
307 | struct perf_domain *pd) | |
308 | { | |
309 | if (!sched_debug() || !pd) | |
310 | return; | |
311 | ||
312 | printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map)); | |
313 | ||
314 | while (pd) { | |
521b512b | 315 | printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_pstate=%d }", |
6aa140fa QP |
316 | cpumask_first(perf_domain_span(pd)), |
317 | cpumask_pr_args(perf_domain_span(pd)), | |
521b512b | 318 | em_pd_nr_perf_states(pd->em_pd)); |
6aa140fa QP |
319 | pd = pd->next; |
320 | } | |
321 | ||
322 | printk(KERN_CONT "\n"); | |
323 | } | |
324 | ||
325 | static void destroy_perf_domain_rcu(struct rcu_head *rp) | |
326 | { | |
327 | struct perf_domain *pd; | |
328 | ||
329 | pd = container_of(rp, struct perf_domain, rcu); | |
330 | free_pd(pd); | |
331 | } | |
332 | ||
1f74de87 QP |
333 | static void sched_energy_set(bool has_eas) |
334 | { | |
335 | if (!has_eas && static_branch_unlikely(&sched_energy_present)) { | |
336 | if (sched_debug()) | |
337 | pr_info("%s: stopping EAS\n", __func__); | |
338 | static_branch_disable_cpuslocked(&sched_energy_present); | |
339 | } else if (has_eas && !static_branch_unlikely(&sched_energy_present)) { | |
340 | if (sched_debug()) | |
341 | pr_info("%s: starting EAS\n", __func__); | |
342 | static_branch_enable_cpuslocked(&sched_energy_present); | |
343 | } | |
344 | } | |
345 | ||
b68a4c0d QP |
346 | /* |
347 | * EAS can be used on a root domain if it meets all the following conditions: | |
348 | * 1. an Energy Model (EM) is available; | |
349 | * 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy. | |
38502ab4 VS |
350 | * 3. no SMT is detected. |
351 | * 4. the EM complexity is low enough to keep scheduling overheads low; | |
352 | * 5. schedutil is driving the frequency of all CPUs of the rd; | |
fa50e2b4 | 353 | * 6. frequency invariance support is present; |
b68a4c0d QP |
354 | * |
355 | * The complexity of the Energy Model is defined as: | |
356 | * | |
521b512b | 357 | * C = nr_pd * (nr_cpus + nr_ps) |
b68a4c0d QP |
358 | * |
359 | * with parameters defined as: | |
360 | * - nr_pd: the number of performance domains | |
361 | * - nr_cpus: the number of CPUs | |
521b512b | 362 | * - nr_ps: the sum of the number of performance states of all performance |
b68a4c0d | 363 | * domains (for example, on a system with 2 performance domains, |
521b512b | 364 | * with 10 performance states each, nr_ps = 2 * 10 = 20). |
b68a4c0d QP |
365 | * |
366 | * It is generally not a good idea to use such a model in the wake-up path on | |
367 | * very complex platforms because of the associated scheduling overheads. The | |
368 | * arbitrary constraint below prevents that. It makes EAS usable up to 16 CPUs | |
521b512b | 369 | * with per-CPU DVFS and less than 8 performance states each, for example. |
b68a4c0d QP |
370 | */ |
371 | #define EM_MAX_COMPLEXITY 2048 | |
372 | ||
531b5c9f | 373 | extern struct cpufreq_governor schedutil_gov; |
1f74de87 | 374 | static bool build_perf_domains(const struct cpumask *cpu_map) |
6aa140fa | 375 | { |
521b512b | 376 | int i, nr_pd = 0, nr_ps = 0, nr_cpus = cpumask_weight(cpu_map); |
6aa140fa QP |
377 | struct perf_domain *pd = NULL, *tmp; |
378 | int cpu = cpumask_first(cpu_map); | |
379 | struct root_domain *rd = cpu_rq(cpu)->rd; | |
531b5c9f QP |
380 | struct cpufreq_policy *policy; |
381 | struct cpufreq_governor *gov; | |
b68a4c0d | 382 | |
8d5d0cfb QP |
383 | if (!sysctl_sched_energy_aware) |
384 | goto free; | |
385 | ||
b68a4c0d QP |
386 | /* EAS is enabled for asymmetric CPU capacity topologies. */ |
387 | if (!per_cpu(sd_asym_cpucapacity, cpu)) { | |
388 | if (sched_debug()) { | |
389 | pr_info("rd %*pbl: CPUs do not have asymmetric capacities\n", | |
390 | cpumask_pr_args(cpu_map)); | |
391 | } | |
392 | goto free; | |
393 | } | |
6aa140fa | 394 | |
38502ab4 VS |
395 | /* EAS definitely does *not* handle SMT */ |
396 | if (sched_smt_active()) { | |
397 | pr_warn("rd %*pbl: Disabling EAS, SMT is not supported\n", | |
398 | cpumask_pr_args(cpu_map)); | |
399 | goto free; | |
400 | } | |
401 | ||
fa50e2b4 IV |
402 | if (!arch_scale_freq_invariant()) { |
403 | if (sched_debug()) { | |
404 | pr_warn("rd %*pbl: Disabling EAS: frequency-invariant load tracking not yet supported", | |
405 | cpumask_pr_args(cpu_map)); | |
406 | } | |
407 | goto free; | |
408 | } | |
409 | ||
6aa140fa QP |
410 | for_each_cpu(i, cpu_map) { |
411 | /* Skip already covered CPUs. */ | |
412 | if (find_pd(pd, i)) | |
413 | continue; | |
414 | ||
531b5c9f QP |
415 | /* Do not attempt EAS if schedutil is not being used. */ |
416 | policy = cpufreq_cpu_get(i); | |
417 | if (!policy) | |
418 | goto free; | |
419 | gov = policy->governor; | |
420 | cpufreq_cpu_put(policy); | |
421 | if (gov != &schedutil_gov) { | |
422 | if (rd->pd) | |
423 | pr_warn("rd %*pbl: Disabling EAS, schedutil is mandatory\n", | |
424 | cpumask_pr_args(cpu_map)); | |
425 | goto free; | |
426 | } | |
427 | ||
6aa140fa QP |
428 | /* Create the new pd and add it to the local list. */ |
429 | tmp = pd_init(i); | |
430 | if (!tmp) | |
431 | goto free; | |
432 | tmp->next = pd; | |
433 | pd = tmp; | |
b68a4c0d QP |
434 | |
435 | /* | |
521b512b | 436 | * Count performance domains and performance states for the |
b68a4c0d QP |
437 | * complexity check. |
438 | */ | |
439 | nr_pd++; | |
521b512b | 440 | nr_ps += em_pd_nr_perf_states(pd->em_pd); |
b68a4c0d QP |
441 | } |
442 | ||
443 | /* Bail out if the Energy Model complexity is too high. */ | |
521b512b | 444 | if (nr_pd * (nr_ps + nr_cpus) > EM_MAX_COMPLEXITY) { |
b68a4c0d QP |
445 | WARN(1, "rd %*pbl: Failed to start EAS, EM complexity is too high\n", |
446 | cpumask_pr_args(cpu_map)); | |
447 | goto free; | |
6aa140fa QP |
448 | } |
449 | ||
450 | perf_domain_debug(cpu_map, pd); | |
451 | ||
452 | /* Attach the new list of performance domains to the root domain. */ | |
453 | tmp = rd->pd; | |
454 | rcu_assign_pointer(rd->pd, pd); | |
455 | if (tmp) | |
456 | call_rcu(&tmp->rcu, destroy_perf_domain_rcu); | |
457 | ||
1f74de87 | 458 | return !!pd; |
6aa140fa QP |
459 | |
460 | free: | |
461 | free_pd(pd); | |
462 | tmp = rd->pd; | |
463 | rcu_assign_pointer(rd->pd, NULL); | |
464 | if (tmp) | |
465 | call_rcu(&tmp->rcu, destroy_perf_domain_rcu); | |
1f74de87 QP |
466 | |
467 | return false; | |
6aa140fa QP |
468 | } |
469 | #else | |
470 | static void free_pd(struct perf_domain *pd) { } | |
531b5c9f | 471 | #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/ |
6aa140fa | 472 | |
f2cb1360 IM |
473 | static void free_rootdomain(struct rcu_head *rcu) |
474 | { | |
475 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); | |
476 | ||
477 | cpupri_cleanup(&rd->cpupri); | |
478 | cpudl_cleanup(&rd->cpudl); | |
479 | free_cpumask_var(rd->dlo_mask); | |
480 | free_cpumask_var(rd->rto_mask); | |
481 | free_cpumask_var(rd->online); | |
482 | free_cpumask_var(rd->span); | |
6aa140fa | 483 | free_pd(rd->pd); |
f2cb1360 IM |
484 | kfree(rd); |
485 | } | |
486 | ||
487 | void rq_attach_root(struct rq *rq, struct root_domain *rd) | |
488 | { | |
489 | struct root_domain *old_rd = NULL; | |
490 | unsigned long flags; | |
491 | ||
5cb9eaa3 | 492 | raw_spin_rq_lock_irqsave(rq, flags); |
f2cb1360 IM |
493 | |
494 | if (rq->rd) { | |
495 | old_rd = rq->rd; | |
496 | ||
497 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) | |
498 | set_rq_offline(rq); | |
499 | ||
500 | cpumask_clear_cpu(rq->cpu, old_rd->span); | |
501 | ||
502 | /* | |
503 | * If we dont want to free the old_rd yet then | |
504 | * set old_rd to NULL to skip the freeing later | |
505 | * in this function: | |
506 | */ | |
507 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
508 | old_rd = NULL; | |
509 | } | |
510 | ||
511 | atomic_inc(&rd->refcount); | |
512 | rq->rd = rd; | |
513 | ||
514 | cpumask_set_cpu(rq->cpu, rd->span); | |
515 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) | |
516 | set_rq_online(rq); | |
517 | ||
5cb9eaa3 | 518 | raw_spin_rq_unlock_irqrestore(rq, flags); |
f2cb1360 IM |
519 | |
520 | if (old_rd) | |
337e9b07 | 521 | call_rcu(&old_rd->rcu, free_rootdomain); |
f2cb1360 IM |
522 | } |
523 | ||
364f5665 SRV |
524 | void sched_get_rd(struct root_domain *rd) |
525 | { | |
526 | atomic_inc(&rd->refcount); | |
527 | } | |
528 | ||
529 | void sched_put_rd(struct root_domain *rd) | |
530 | { | |
531 | if (!atomic_dec_and_test(&rd->refcount)) | |
532 | return; | |
533 | ||
337e9b07 | 534 | call_rcu(&rd->rcu, free_rootdomain); |
364f5665 SRV |
535 | } |
536 | ||
f2cb1360 IM |
537 | static int init_rootdomain(struct root_domain *rd) |
538 | { | |
f2cb1360 IM |
539 | if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL)) |
540 | goto out; | |
541 | if (!zalloc_cpumask_var(&rd->online, GFP_KERNEL)) | |
542 | goto free_span; | |
543 | if (!zalloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) | |
544 | goto free_online; | |
545 | if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) | |
546 | goto free_dlo_mask; | |
547 | ||
4bdced5c SRRH |
548 | #ifdef HAVE_RT_PUSH_IPI |
549 | rd->rto_cpu = -1; | |
550 | raw_spin_lock_init(&rd->rto_lock); | |
da6ff099 | 551 | rd->rto_push_work = IRQ_WORK_INIT_HARD(rto_push_irq_work_func); |
4bdced5c SRRH |
552 | #endif |
553 | ||
26762423 | 554 | rd->visit_gen = 0; |
f2cb1360 IM |
555 | init_dl_bw(&rd->dl_bw); |
556 | if (cpudl_init(&rd->cpudl) != 0) | |
557 | goto free_rto_mask; | |
558 | ||
559 | if (cpupri_init(&rd->cpupri) != 0) | |
560 | goto free_cpudl; | |
561 | return 0; | |
562 | ||
563 | free_cpudl: | |
564 | cpudl_cleanup(&rd->cpudl); | |
565 | free_rto_mask: | |
566 | free_cpumask_var(rd->rto_mask); | |
567 | free_dlo_mask: | |
568 | free_cpumask_var(rd->dlo_mask); | |
569 | free_online: | |
570 | free_cpumask_var(rd->online); | |
571 | free_span: | |
572 | free_cpumask_var(rd->span); | |
573 | out: | |
574 | return -ENOMEM; | |
575 | } | |
576 | ||
577 | /* | |
578 | * By default the system creates a single root-domain with all CPUs as | |
579 | * members (mimicking the global state we have today). | |
580 | */ | |
581 | struct root_domain def_root_domain; | |
582 | ||
9a5322db | 583 | void __init init_defrootdomain(void) |
f2cb1360 IM |
584 | { |
585 | init_rootdomain(&def_root_domain); | |
586 | ||
587 | atomic_set(&def_root_domain.refcount, 1); | |
588 | } | |
589 | ||
590 | static struct root_domain *alloc_rootdomain(void) | |
591 | { | |
592 | struct root_domain *rd; | |
593 | ||
4d13a06d | 594 | rd = kzalloc(sizeof(*rd), GFP_KERNEL); |
f2cb1360 IM |
595 | if (!rd) |
596 | return NULL; | |
597 | ||
598 | if (init_rootdomain(rd) != 0) { | |
599 | kfree(rd); | |
600 | return NULL; | |
601 | } | |
602 | ||
603 | return rd; | |
604 | } | |
605 | ||
606 | static void free_sched_groups(struct sched_group *sg, int free_sgc) | |
607 | { | |
608 | struct sched_group *tmp, *first; | |
609 | ||
610 | if (!sg) | |
611 | return; | |
612 | ||
613 | first = sg; | |
614 | do { | |
615 | tmp = sg->next; | |
616 | ||
617 | if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) | |
618 | kfree(sg->sgc); | |
619 | ||
213c5a45 SW |
620 | if (atomic_dec_and_test(&sg->ref)) |
621 | kfree(sg); | |
f2cb1360 IM |
622 | sg = tmp; |
623 | } while (sg != first); | |
624 | } | |
625 | ||
626 | static void destroy_sched_domain(struct sched_domain *sd) | |
627 | { | |
628 | /* | |
a090c4f2 PZ |
629 | * A normal sched domain may have multiple group references, an |
630 | * overlapping domain, having private groups, only one. Iterate, | |
631 | * dropping group/capacity references, freeing where none remain. | |
f2cb1360 | 632 | */ |
213c5a45 SW |
633 | free_sched_groups(sd->groups, 1); |
634 | ||
f2cb1360 IM |
635 | if (sd->shared && atomic_dec_and_test(&sd->shared->ref)) |
636 | kfree(sd->shared); | |
637 | kfree(sd); | |
638 | } | |
639 | ||
640 | static void destroy_sched_domains_rcu(struct rcu_head *rcu) | |
641 | { | |
642 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
643 | ||
644 | while (sd) { | |
645 | struct sched_domain *parent = sd->parent; | |
646 | destroy_sched_domain(sd); | |
647 | sd = parent; | |
648 | } | |
649 | } | |
650 | ||
651 | static void destroy_sched_domains(struct sched_domain *sd) | |
652 | { | |
653 | if (sd) | |
654 | call_rcu(&sd->rcu, destroy_sched_domains_rcu); | |
655 | } | |
656 | ||
657 | /* | |
658 | * Keep a special pointer to the highest sched_domain that has | |
659 | * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this | |
660 | * allows us to avoid some pointer chasing select_idle_sibling(). | |
661 | * | |
662 | * Also keep a unique ID per domain (we use the first CPU number in | |
663 | * the cpumask of the domain), this allows us to quickly tell if | |
664 | * two CPUs are in the same cache domain, see cpus_share_cache(). | |
665 | */ | |
994aeb7a | 666 | DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc); |
f2cb1360 IM |
667 | DEFINE_PER_CPU(int, sd_llc_size); |
668 | DEFINE_PER_CPU(int, sd_llc_id); | |
994aeb7a JFG |
669 | DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); |
670 | DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); | |
671 | DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); | |
672 | DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); | |
df054e84 | 673 | DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); |
f2cb1360 IM |
674 | |
675 | static void update_top_cache_domain(int cpu) | |
676 | { | |
677 | struct sched_domain_shared *sds = NULL; | |
678 | struct sched_domain *sd; | |
679 | int id = cpu; | |
680 | int size = 1; | |
681 | ||
682 | sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); | |
683 | if (sd) { | |
684 | id = cpumask_first(sched_domain_span(sd)); | |
685 | size = cpumask_weight(sched_domain_span(sd)); | |
686 | sds = sd->shared; | |
687 | } | |
688 | ||
689 | rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); | |
690 | per_cpu(sd_llc_size, cpu) = size; | |
691 | per_cpu(sd_llc_id, cpu) = id; | |
692 | rcu_assign_pointer(per_cpu(sd_llc_shared, cpu), sds); | |
693 | ||
694 | sd = lowest_flag_domain(cpu, SD_NUMA); | |
695 | rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); | |
696 | ||
697 | sd = highest_flag_domain(cpu, SD_ASYM_PACKING); | |
011b27bb QP |
698 | rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd); |
699 | ||
c744dc4a | 700 | sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY_FULL); |
011b27bb | 701 | rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd); |
f2cb1360 IM |
702 | } |
703 | ||
704 | /* | |
705 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must | |
706 | * hold the hotplug lock. | |
707 | */ | |
708 | static void | |
709 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
710 | { | |
711 | struct rq *rq = cpu_rq(cpu); | |
712 | struct sched_domain *tmp; | |
713 | ||
714 | /* Remove the sched domains which do not contribute to scheduling. */ | |
715 | for (tmp = sd; tmp; ) { | |
716 | struct sched_domain *parent = tmp->parent; | |
717 | if (!parent) | |
718 | break; | |
719 | ||
720 | if (sd_parent_degenerate(tmp, parent)) { | |
721 | tmp->parent = parent->parent; | |
722 | if (parent->parent) | |
723 | parent->parent->child = tmp; | |
724 | /* | |
725 | * Transfer SD_PREFER_SIBLING down in case of a | |
726 | * degenerate parent; the spans match for this | |
727 | * so the property transfers. | |
728 | */ | |
729 | if (parent->flags & SD_PREFER_SIBLING) | |
730 | tmp->flags |= SD_PREFER_SIBLING; | |
731 | destroy_sched_domain(parent); | |
732 | } else | |
733 | tmp = tmp->parent; | |
734 | } | |
735 | ||
736 | if (sd && sd_degenerate(sd)) { | |
737 | tmp = sd; | |
738 | sd = sd->parent; | |
739 | destroy_sched_domain(tmp); | |
16d364ba RN |
740 | if (sd) { |
741 | struct sched_group *sg = sd->groups; | |
742 | ||
743 | /* | |
744 | * sched groups hold the flags of the child sched | |
745 | * domain for convenience. Clear such flags since | |
746 | * the child is being destroyed. | |
747 | */ | |
748 | do { | |
749 | sg->flags = 0; | |
750 | } while (sg != sd->groups); | |
751 | ||
f2cb1360 | 752 | sd->child = NULL; |
16d364ba | 753 | } |
f2cb1360 IM |
754 | } |
755 | ||
756 | sched_domain_debug(sd, cpu); | |
757 | ||
758 | rq_attach_root(rq, rd); | |
759 | tmp = rq->sd; | |
760 | rcu_assign_pointer(rq->sd, sd); | |
bbdacdfe | 761 | dirty_sched_domain_sysctl(cpu); |
f2cb1360 IM |
762 | destroy_sched_domains(tmp); |
763 | ||
764 | update_top_cache_domain(cpu); | |
765 | } | |
766 | ||
f2cb1360 | 767 | struct s_data { |
99687cdb | 768 | struct sched_domain * __percpu *sd; |
f2cb1360 IM |
769 | struct root_domain *rd; |
770 | }; | |
771 | ||
772 | enum s_alloc { | |
773 | sa_rootdomain, | |
774 | sa_sd, | |
775 | sa_sd_storage, | |
776 | sa_none, | |
777 | }; | |
778 | ||
35a566e6 PZ |
779 | /* |
780 | * Return the canonical balance CPU for this group, this is the first CPU | |
e5c14b1f | 781 | * of this group that's also in the balance mask. |
35a566e6 | 782 | * |
e5c14b1f PZ |
783 | * The balance mask are all those CPUs that could actually end up at this |
784 | * group. See build_balance_mask(). | |
35a566e6 PZ |
785 | * |
786 | * Also see should_we_balance(). | |
787 | */ | |
788 | int group_balance_cpu(struct sched_group *sg) | |
789 | { | |
e5c14b1f | 790 | return cpumask_first(group_balance_mask(sg)); |
35a566e6 PZ |
791 | } |
792 | ||
793 | ||
794 | /* | |
795 | * NUMA topology (first read the regular topology blurb below) | |
796 | * | |
797 | * Given a node-distance table, for example: | |
798 | * | |
799 | * node 0 1 2 3 | |
800 | * 0: 10 20 30 20 | |
801 | * 1: 20 10 20 30 | |
802 | * 2: 30 20 10 20 | |
803 | * 3: 20 30 20 10 | |
804 | * | |
805 | * which represents a 4 node ring topology like: | |
806 | * | |
807 | * 0 ----- 1 | |
808 | * | | | |
809 | * | | | |
810 | * | | | |
811 | * 3 ----- 2 | |
812 | * | |
813 | * We want to construct domains and groups to represent this. The way we go | |
814 | * about doing this is to build the domains on 'hops'. For each NUMA level we | |
815 | * construct the mask of all nodes reachable in @level hops. | |
816 | * | |
817 | * For the above NUMA topology that gives 3 levels: | |
818 | * | |
819 | * NUMA-2 0-3 0-3 0-3 0-3 | |
820 | * groups: {0-1,3},{1-3} {0-2},{0,2-3} {1-3},{0-1,3} {0,2-3},{0-2} | |
821 | * | |
822 | * NUMA-1 0-1,3 0-2 1-3 0,2-3 | |
823 | * groups: {0},{1},{3} {0},{1},{2} {1},{2},{3} {0},{2},{3} | |
824 | * | |
825 | * NUMA-0 0 1 2 3 | |
826 | * | |
827 | * | |
828 | * As can be seen; things don't nicely line up as with the regular topology. | |
829 | * When we iterate a domain in child domain chunks some nodes can be | |
830 | * represented multiple times -- hence the "overlap" naming for this part of | |
831 | * the topology. | |
832 | * | |
833 | * In order to minimize this overlap, we only build enough groups to cover the | |
834 | * domain. For instance Node-0 NUMA-2 would only get groups: 0-1,3 and 1-3. | |
835 | * | |
836 | * Because: | |
837 | * | |
838 | * - the first group of each domain is its child domain; this | |
839 | * gets us the first 0-1,3 | |
840 | * - the only uncovered node is 2, who's child domain is 1-3. | |
841 | * | |
842 | * However, because of the overlap, computing a unique CPU for each group is | |
843 | * more complicated. Consider for instance the groups of NODE-1 NUMA-2, both | |
844 | * groups include the CPUs of Node-0, while those CPUs would not in fact ever | |
845 | * end up at those groups (they would end up in group: 0-1,3). | |
846 | * | |
e5c14b1f | 847 | * To correct this we have to introduce the group balance mask. This mask |
35a566e6 PZ |
848 | * will contain those CPUs in the group that can reach this group given the |
849 | * (child) domain tree. | |
850 | * | |
851 | * With this we can once again compute balance_cpu and sched_group_capacity | |
852 | * relations. | |
853 | * | |
854 | * XXX include words on how balance_cpu is unique and therefore can be | |
855 | * used for sched_group_capacity links. | |
856 | * | |
857 | * | |
858 | * Another 'interesting' topology is: | |
859 | * | |
860 | * node 0 1 2 3 | |
861 | * 0: 10 20 20 30 | |
862 | * 1: 20 10 20 20 | |
863 | * 2: 20 20 10 20 | |
864 | * 3: 30 20 20 10 | |
865 | * | |
866 | * Which looks a little like: | |
867 | * | |
868 | * 0 ----- 1 | |
869 | * | / | | |
870 | * | / | | |
871 | * | / | | |
872 | * 2 ----- 3 | |
873 | * | |
874 | * This topology is asymmetric, nodes 1,2 are fully connected, but nodes 0,3 | |
875 | * are not. | |
876 | * | |
877 | * This leads to a few particularly weird cases where the sched_domain's are | |
97fb7a0a | 878 | * not of the same number for each CPU. Consider: |
35a566e6 PZ |
879 | * |
880 | * NUMA-2 0-3 0-3 | |
881 | * groups: {0-2},{1-3} {1-3},{0-2} | |
882 | * | |
883 | * NUMA-1 0-2 0-3 0-3 1-3 | |
884 | * | |
885 | * NUMA-0 0 1 2 3 | |
886 | * | |
887 | */ | |
888 | ||
889 | ||
f2cb1360 | 890 | /* |
e5c14b1f PZ |
891 | * Build the balance mask; it contains only those CPUs that can arrive at this |
892 | * group and should be considered to continue balancing. | |
35a566e6 PZ |
893 | * |
894 | * We do this during the group creation pass, therefore the group information | |
895 | * isn't complete yet, however since each group represents a (child) domain we | |
896 | * can fully construct this using the sched_domain bits (which are already | |
897 | * complete). | |
f2cb1360 | 898 | */ |
1676330e | 899 | static void |
e5c14b1f | 900 | build_balance_mask(struct sched_domain *sd, struct sched_group *sg, struct cpumask *mask) |
f2cb1360 | 901 | { |
ae4df9d6 | 902 | const struct cpumask *sg_span = sched_group_span(sg); |
f2cb1360 IM |
903 | struct sd_data *sdd = sd->private; |
904 | struct sched_domain *sibling; | |
905 | int i; | |
906 | ||
1676330e PZ |
907 | cpumask_clear(mask); |
908 | ||
f32d782e | 909 | for_each_cpu(i, sg_span) { |
f2cb1360 | 910 | sibling = *per_cpu_ptr(sdd->sd, i); |
73bb059f PZ |
911 | |
912 | /* | |
913 | * Can happen in the asymmetric case, where these siblings are | |
914 | * unused. The mask will not be empty because those CPUs that | |
915 | * do have the top domain _should_ span the domain. | |
916 | */ | |
917 | if (!sibling->child) | |
918 | continue; | |
919 | ||
920 | /* If we would not end up here, we can't continue from here */ | |
921 | if (!cpumask_equal(sg_span, sched_domain_span(sibling->child))) | |
f2cb1360 IM |
922 | continue; |
923 | ||
1676330e | 924 | cpumask_set_cpu(i, mask); |
f2cb1360 | 925 | } |
73bb059f PZ |
926 | |
927 | /* We must not have empty masks here */ | |
1676330e | 928 | WARN_ON_ONCE(cpumask_empty(mask)); |
f2cb1360 IM |
929 | } |
930 | ||
931 | /* | |
35a566e6 PZ |
932 | * XXX: This creates per-node group entries; since the load-balancer will |
933 | * immediately access remote memory to construct this group's load-balance | |
934 | * statistics having the groups node local is of dubious benefit. | |
f2cb1360 | 935 | */ |
8c033469 LRV |
936 | static struct sched_group * |
937 | build_group_from_child_sched_domain(struct sched_domain *sd, int cpu) | |
938 | { | |
939 | struct sched_group *sg; | |
940 | struct cpumask *sg_span; | |
941 | ||
942 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
943 | GFP_KERNEL, cpu_to_node(cpu)); | |
944 | ||
945 | if (!sg) | |
946 | return NULL; | |
947 | ||
ae4df9d6 | 948 | sg_span = sched_group_span(sg); |
16d364ba | 949 | if (sd->child) { |
8c033469 | 950 | cpumask_copy(sg_span, sched_domain_span(sd->child)); |
16d364ba RN |
951 | sg->flags = sd->child->flags; |
952 | } else { | |
8c033469 | 953 | cpumask_copy(sg_span, sched_domain_span(sd)); |
16d364ba | 954 | } |
8c033469 | 955 | |
213c5a45 | 956 | atomic_inc(&sg->ref); |
8c033469 LRV |
957 | return sg; |
958 | } | |
959 | ||
960 | static void init_overlap_sched_group(struct sched_domain *sd, | |
1676330e | 961 | struct sched_group *sg) |
8c033469 | 962 | { |
1676330e | 963 | struct cpumask *mask = sched_domains_tmpmask2; |
8c033469 LRV |
964 | struct sd_data *sdd = sd->private; |
965 | struct cpumask *sg_span; | |
1676330e PZ |
966 | int cpu; |
967 | ||
e5c14b1f | 968 | build_balance_mask(sd, sg, mask); |
0a2b65c0 | 969 | cpu = cpumask_first(mask); |
8c033469 LRV |
970 | |
971 | sg->sgc = *per_cpu_ptr(sdd->sgc, cpu); | |
972 | if (atomic_inc_return(&sg->sgc->ref) == 1) | |
e5c14b1f | 973 | cpumask_copy(group_balance_mask(sg), mask); |
35a566e6 | 974 | else |
e5c14b1f | 975 | WARN_ON_ONCE(!cpumask_equal(group_balance_mask(sg), mask)); |
8c033469 LRV |
976 | |
977 | /* | |
978 | * Initialize sgc->capacity such that even if we mess up the | |
979 | * domains and no possible iteration will get us here, we won't | |
980 | * die on a /0 trap. | |
981 | */ | |
ae4df9d6 | 982 | sg_span = sched_group_span(sg); |
8c033469 LRV |
983 | sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); |
984 | sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; | |
e3d6d0cb | 985 | sg->sgc->max_capacity = SCHED_CAPACITY_SCALE; |
8c033469 LRV |
986 | } |
987 | ||
585b6d27 BS |
988 | static struct sched_domain * |
989 | find_descended_sibling(struct sched_domain *sd, struct sched_domain *sibling) | |
990 | { | |
991 | /* | |
992 | * The proper descendant would be the one whose child won't span out | |
993 | * of sd | |
994 | */ | |
995 | while (sibling->child && | |
996 | !cpumask_subset(sched_domain_span(sibling->child), | |
997 | sched_domain_span(sd))) | |
998 | sibling = sibling->child; | |
999 | ||
1000 | /* | |
1001 | * As we are referencing sgc across different topology level, we need | |
1002 | * to go down to skip those sched_domains which don't contribute to | |
1003 | * scheduling because they will be degenerated in cpu_attach_domain | |
1004 | */ | |
1005 | while (sibling->child && | |
1006 | cpumask_equal(sched_domain_span(sibling->child), | |
1007 | sched_domain_span(sibling))) | |
1008 | sibling = sibling->child; | |
1009 | ||
1010 | return sibling; | |
1011 | } | |
1012 | ||
f2cb1360 IM |
1013 | static int |
1014 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
1015 | { | |
91eaed0d | 1016 | struct sched_group *first = NULL, *last = NULL, *sg; |
f2cb1360 IM |
1017 | const struct cpumask *span = sched_domain_span(sd); |
1018 | struct cpumask *covered = sched_domains_tmpmask; | |
1019 | struct sd_data *sdd = sd->private; | |
1020 | struct sched_domain *sibling; | |
1021 | int i; | |
1022 | ||
1023 | cpumask_clear(covered); | |
1024 | ||
0372dd27 | 1025 | for_each_cpu_wrap(i, span, cpu) { |
f2cb1360 IM |
1026 | struct cpumask *sg_span; |
1027 | ||
1028 | if (cpumask_test_cpu(i, covered)) | |
1029 | continue; | |
1030 | ||
1031 | sibling = *per_cpu_ptr(sdd->sd, i); | |
1032 | ||
c20e1ea4 LRV |
1033 | /* |
1034 | * Asymmetric node setups can result in situations where the | |
1035 | * domain tree is of unequal depth, make sure to skip domains | |
1036 | * that already cover the entire range. | |
1037 | * | |
1038 | * In that case build_sched_domains() will have terminated the | |
1039 | * iteration early and our sibling sd spans will be empty. | |
1040 | * Domains should always include the CPU they're built on, so | |
1041 | * check that. | |
1042 | */ | |
f2cb1360 IM |
1043 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) |
1044 | continue; | |
1045 | ||
585b6d27 BS |
1046 | /* |
1047 | * Usually we build sched_group by sibling's child sched_domain | |
1048 | * But for machines whose NUMA diameter are 3 or above, we move | |
1049 | * to build sched_group by sibling's proper descendant's child | |
1050 | * domain because sibling's child sched_domain will span out of | |
1051 | * the sched_domain being built as below. | |
1052 | * | |
1053 | * Smallest diameter=3 topology is: | |
1054 | * | |
1055 | * node 0 1 2 3 | |
1056 | * 0: 10 20 30 40 | |
1057 | * 1: 20 10 20 30 | |
1058 | * 2: 30 20 10 20 | |
1059 | * 3: 40 30 20 10 | |
1060 | * | |
1061 | * 0 --- 1 --- 2 --- 3 | |
1062 | * | |
1063 | * NUMA-3 0-3 N/A N/A 0-3 | |
1064 | * groups: {0-2},{1-3} {1-3},{0-2} | |
1065 | * | |
1066 | * NUMA-2 0-2 0-3 0-3 1-3 | |
1067 | * groups: {0-1},{1-3} {0-2},{2-3} {1-3},{0-1} {2-3},{0-2} | |
1068 | * | |
1069 | * NUMA-1 0-1 0-2 1-3 2-3 | |
1070 | * groups: {0},{1} {1},{2},{0} {2},{3},{1} {3},{2} | |
1071 | * | |
1072 | * NUMA-0 0 1 2 3 | |
1073 | * | |
1074 | * The NUMA-2 groups for nodes 0 and 3 are obviously buggered, as the | |
1075 | * group span isn't a subset of the domain span. | |
1076 | */ | |
1077 | if (sibling->child && | |
1078 | !cpumask_subset(sched_domain_span(sibling->child), span)) | |
1079 | sibling = find_descended_sibling(sd, sibling); | |
1080 | ||
8c033469 | 1081 | sg = build_group_from_child_sched_domain(sibling, cpu); |
f2cb1360 IM |
1082 | if (!sg) |
1083 | goto fail; | |
1084 | ||
ae4df9d6 | 1085 | sg_span = sched_group_span(sg); |
f2cb1360 IM |
1086 | cpumask_or(covered, covered, sg_span); |
1087 | ||
585b6d27 | 1088 | init_overlap_sched_group(sibling, sg); |
f2cb1360 | 1089 | |
f2cb1360 IM |
1090 | if (!first) |
1091 | first = sg; | |
1092 | if (last) | |
1093 | last->next = sg; | |
1094 | last = sg; | |
1095 | last->next = first; | |
1096 | } | |
91eaed0d | 1097 | sd->groups = first; |
f2cb1360 IM |
1098 | |
1099 | return 0; | |
1100 | ||
1101 | fail: | |
1102 | free_sched_groups(first, 0); | |
1103 | ||
1104 | return -ENOMEM; | |
1105 | } | |
1106 | ||
35a566e6 PZ |
1107 | |
1108 | /* | |
1109 | * Package topology (also see the load-balance blurb in fair.c) | |
1110 | * | |
1111 | * The scheduler builds a tree structure to represent a number of important | |
1112 | * topology features. By default (default_topology[]) these include: | |
1113 | * | |
1114 | * - Simultaneous multithreading (SMT) | |
1115 | * - Multi-Core Cache (MC) | |
1116 | * - Package (DIE) | |
1117 | * | |
1118 | * Where the last one more or less denotes everything up to a NUMA node. | |
1119 | * | |
1120 | * The tree consists of 3 primary data structures: | |
1121 | * | |
1122 | * sched_domain -> sched_group -> sched_group_capacity | |
1123 | * ^ ^ ^ ^ | |
1124 | * `-' `-' | |
1125 | * | |
97fb7a0a | 1126 | * The sched_domains are per-CPU and have a two way link (parent & child) and |
35a566e6 PZ |
1127 | * denote the ever growing mask of CPUs belonging to that level of topology. |
1128 | * | |
1129 | * Each sched_domain has a circular (double) linked list of sched_group's, each | |
1130 | * denoting the domains of the level below (or individual CPUs in case of the | |
1131 | * first domain level). The sched_group linked by a sched_domain includes the | |
1132 | * CPU of that sched_domain [*]. | |
1133 | * | |
1134 | * Take for instance a 2 threaded, 2 core, 2 cache cluster part: | |
1135 | * | |
1136 | * CPU 0 1 2 3 4 5 6 7 | |
1137 | * | |
1138 | * DIE [ ] | |
1139 | * MC [ ] [ ] | |
1140 | * SMT [ ] [ ] [ ] [ ] | |
1141 | * | |
1142 | * - or - | |
1143 | * | |
1144 | * DIE 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7 | |
1145 | * MC 0-3 0-3 0-3 0-3 4-7 4-7 4-7 4-7 | |
1146 | * SMT 0-1 0-1 2-3 2-3 4-5 4-5 6-7 6-7 | |
1147 | * | |
1148 | * CPU 0 1 2 3 4 5 6 7 | |
1149 | * | |
1150 | * One way to think about it is: sched_domain moves you up and down among these | |
1151 | * topology levels, while sched_group moves you sideways through it, at child | |
1152 | * domain granularity. | |
1153 | * | |
1154 | * sched_group_capacity ensures each unique sched_group has shared storage. | |
1155 | * | |
1156 | * There are two related construction problems, both require a CPU that | |
1157 | * uniquely identify each group (for a given domain): | |
1158 | * | |
1159 | * - The first is the balance_cpu (see should_we_balance() and the | |
1160 | * load-balance blub in fair.c); for each group we only want 1 CPU to | |
1161 | * continue balancing at a higher domain. | |
1162 | * | |
1163 | * - The second is the sched_group_capacity; we want all identical groups | |
1164 | * to share a single sched_group_capacity. | |
1165 | * | |
1166 | * Since these topologies are exclusive by construction. That is, its | |
1167 | * impossible for an SMT thread to belong to multiple cores, and cores to | |
1168 | * be part of multiple caches. There is a very clear and unique location | |
1169 | * for each CPU in the hierarchy. | |
1170 | * | |
1171 | * Therefore computing a unique CPU for each group is trivial (the iteration | |
1172 | * mask is redundant and set all 1s; all CPUs in a group will end up at _that_ | |
1173 | * group), we can simply pick the first CPU in each group. | |
1174 | * | |
1175 | * | |
1176 | * [*] in other words, the first group of each domain is its child domain. | |
1177 | */ | |
1178 | ||
0c0e776a | 1179 | static struct sched_group *get_group(int cpu, struct sd_data *sdd) |
f2cb1360 IM |
1180 | { |
1181 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); | |
1182 | struct sched_domain *child = sd->child; | |
0c0e776a | 1183 | struct sched_group *sg; |
67d4f6ff | 1184 | bool already_visited; |
f2cb1360 IM |
1185 | |
1186 | if (child) | |
1187 | cpu = cpumask_first(sched_domain_span(child)); | |
1188 | ||
0c0e776a PZ |
1189 | sg = *per_cpu_ptr(sdd->sg, cpu); |
1190 | sg->sgc = *per_cpu_ptr(sdd->sgc, cpu); | |
1191 | ||
67d4f6ff VS |
1192 | /* Increase refcounts for claim_allocations: */ |
1193 | already_visited = atomic_inc_return(&sg->ref) > 1; | |
1194 | /* sgc visits should follow a similar trend as sg */ | |
1195 | WARN_ON(already_visited != (atomic_inc_return(&sg->sgc->ref) > 1)); | |
1196 | ||
1197 | /* If we have already visited that group, it's already initialized. */ | |
1198 | if (already_visited) | |
1199 | return sg; | |
f2cb1360 | 1200 | |
0c0e776a | 1201 | if (child) { |
ae4df9d6 PZ |
1202 | cpumask_copy(sched_group_span(sg), sched_domain_span(child)); |
1203 | cpumask_copy(group_balance_mask(sg), sched_group_span(sg)); | |
16d364ba | 1204 | sg->flags = child->flags; |
0c0e776a | 1205 | } else { |
ae4df9d6 | 1206 | cpumask_set_cpu(cpu, sched_group_span(sg)); |
e5c14b1f | 1207 | cpumask_set_cpu(cpu, group_balance_mask(sg)); |
f2cb1360 IM |
1208 | } |
1209 | ||
ae4df9d6 | 1210 | sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sched_group_span(sg)); |
0c0e776a | 1211 | sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; |
e3d6d0cb | 1212 | sg->sgc->max_capacity = SCHED_CAPACITY_SCALE; |
0c0e776a PZ |
1213 | |
1214 | return sg; | |
f2cb1360 IM |
1215 | } |
1216 | ||
1217 | /* | |
1218 | * build_sched_groups will build a circular linked list of the groups | |
d8743230 VS |
1219 | * covered by the given span, will set each group's ->cpumask correctly, |
1220 | * and will initialize their ->sgc. | |
f2cb1360 IM |
1221 | * |
1222 | * Assumes the sched_domain tree is fully constructed | |
1223 | */ | |
1224 | static int | |
1225 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1226 | { | |
1227 | struct sched_group *first = NULL, *last = NULL; | |
1228 | struct sd_data *sdd = sd->private; | |
1229 | const struct cpumask *span = sched_domain_span(sd); | |
1230 | struct cpumask *covered; | |
1231 | int i; | |
1232 | ||
f2cb1360 IM |
1233 | lockdep_assert_held(&sched_domains_mutex); |
1234 | covered = sched_domains_tmpmask; | |
1235 | ||
1236 | cpumask_clear(covered); | |
1237 | ||
0c0e776a | 1238 | for_each_cpu_wrap(i, span, cpu) { |
f2cb1360 | 1239 | struct sched_group *sg; |
f2cb1360 IM |
1240 | |
1241 | if (cpumask_test_cpu(i, covered)) | |
1242 | continue; | |
1243 | ||
0c0e776a | 1244 | sg = get_group(i, sdd); |
f2cb1360 | 1245 | |
ae4df9d6 | 1246 | cpumask_or(covered, covered, sched_group_span(sg)); |
f2cb1360 IM |
1247 | |
1248 | if (!first) | |
1249 | first = sg; | |
1250 | if (last) | |
1251 | last->next = sg; | |
1252 | last = sg; | |
1253 | } | |
1254 | last->next = first; | |
0c0e776a | 1255 | sd->groups = first; |
f2cb1360 IM |
1256 | |
1257 | return 0; | |
1258 | } | |
1259 | ||
1260 | /* | |
1261 | * Initialize sched groups cpu_capacity. | |
1262 | * | |
1263 | * cpu_capacity indicates the capacity of sched group, which is used while | |
1264 | * distributing the load between different sched groups in a sched domain. | |
1265 | * Typically cpu_capacity for all the groups in a sched domain will be same | |
1266 | * unless there are asymmetries in the topology. If there are asymmetries, | |
1267 | * group having more cpu_capacity will pickup more load compared to the | |
1268 | * group having less cpu_capacity. | |
1269 | */ | |
1270 | static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) | |
1271 | { | |
1272 | struct sched_group *sg = sd->groups; | |
1273 | ||
1274 | WARN_ON(!sg); | |
1275 | ||
1276 | do { | |
1277 | int cpu, max_cpu = -1; | |
1278 | ||
ae4df9d6 | 1279 | sg->group_weight = cpumask_weight(sched_group_span(sg)); |
f2cb1360 IM |
1280 | |
1281 | if (!(sd->flags & SD_ASYM_PACKING)) | |
1282 | goto next; | |
1283 | ||
ae4df9d6 | 1284 | for_each_cpu(cpu, sched_group_span(sg)) { |
f2cb1360 IM |
1285 | if (max_cpu < 0) |
1286 | max_cpu = cpu; | |
1287 | else if (sched_asym_prefer(cpu, max_cpu)) | |
1288 | max_cpu = cpu; | |
1289 | } | |
1290 | sg->asym_prefer_cpu = max_cpu; | |
1291 | ||
1292 | next: | |
1293 | sg = sg->next; | |
1294 | } while (sg != sd->groups); | |
1295 | ||
1296 | if (cpu != group_balance_cpu(sg)) | |
1297 | return; | |
1298 | ||
1299 | update_group_capacity(sd, cpu); | |
1300 | } | |
1301 | ||
c744dc4a BM |
1302 | /* |
1303 | * Asymmetric CPU capacity bits | |
1304 | */ | |
1305 | struct asym_cap_data { | |
1306 | struct list_head link; | |
1307 | unsigned long capacity; | |
1308 | unsigned long cpus[]; | |
1309 | }; | |
1310 | ||
1311 | /* | |
1312 | * Set of available CPUs grouped by their corresponding capacities | |
1313 | * Each list entry contains a CPU mask reflecting CPUs that share the same | |
1314 | * capacity. | |
1315 | * The lifespan of data is unlimited. | |
1316 | */ | |
1317 | static LIST_HEAD(asym_cap_list); | |
1318 | ||
1319 | #define cpu_capacity_span(asym_data) to_cpumask((asym_data)->cpus) | |
1320 | ||
1321 | /* | |
1322 | * Verify whether there is any CPU capacity asymmetry in a given sched domain. | |
1323 | * Provides sd_flags reflecting the asymmetry scope. | |
1324 | */ | |
1325 | static inline int | |
1326 | asym_cpu_capacity_classify(const struct cpumask *sd_span, | |
1327 | const struct cpumask *cpu_map) | |
1328 | { | |
1329 | struct asym_cap_data *entry; | |
1330 | int count = 0, miss = 0; | |
1331 | ||
1332 | /* | |
1333 | * Count how many unique CPU capacities this domain spans across | |
1334 | * (compare sched_domain CPUs mask with ones representing available | |
1335 | * CPUs capacities). Take into account CPUs that might be offline: | |
1336 | * skip those. | |
1337 | */ | |
1338 | list_for_each_entry(entry, &asym_cap_list, link) { | |
1339 | if (cpumask_intersects(sd_span, cpu_capacity_span(entry))) | |
1340 | ++count; | |
1341 | else if (cpumask_intersects(cpu_map, cpu_capacity_span(entry))) | |
1342 | ++miss; | |
1343 | } | |
1344 | ||
1345 | WARN_ON_ONCE(!count && !list_empty(&asym_cap_list)); | |
1346 | ||
1347 | /* No asymmetry detected */ | |
1348 | if (count < 2) | |
1349 | return 0; | |
1350 | /* Some of the available CPU capacity values have not been detected */ | |
1351 | if (miss) | |
1352 | return SD_ASYM_CPUCAPACITY; | |
1353 | ||
1354 | /* Full asymmetry */ | |
1355 | return SD_ASYM_CPUCAPACITY | SD_ASYM_CPUCAPACITY_FULL; | |
1356 | ||
1357 | } | |
1358 | ||
1359 | static inline void asym_cpu_capacity_update_data(int cpu) | |
1360 | { | |
1361 | unsigned long capacity = arch_scale_cpu_capacity(cpu); | |
1362 | struct asym_cap_data *entry = NULL; | |
1363 | ||
1364 | list_for_each_entry(entry, &asym_cap_list, link) { | |
1365 | if (capacity == entry->capacity) | |
1366 | goto done; | |
1367 | } | |
1368 | ||
1369 | entry = kzalloc(sizeof(*entry) + cpumask_size(), GFP_KERNEL); | |
1370 | if (WARN_ONCE(!entry, "Failed to allocate memory for asymmetry data\n")) | |
1371 | return; | |
1372 | entry->capacity = capacity; | |
1373 | list_add(&entry->link, &asym_cap_list); | |
1374 | done: | |
1375 | __cpumask_set_cpu(cpu, cpu_capacity_span(entry)); | |
1376 | } | |
1377 | ||
1378 | /* | |
1379 | * Build-up/update list of CPUs grouped by their capacities | |
1380 | * An update requires explicit request to rebuild sched domains | |
1381 | * with state indicating CPU topology changes. | |
1382 | */ | |
1383 | static void asym_cpu_capacity_scan(void) | |
1384 | { | |
1385 | struct asym_cap_data *entry, *next; | |
1386 | int cpu; | |
1387 | ||
1388 | list_for_each_entry(entry, &asym_cap_list, link) | |
1389 | cpumask_clear(cpu_capacity_span(entry)); | |
1390 | ||
04d4e665 | 1391 | for_each_cpu_and(cpu, cpu_possible_mask, housekeeping_cpumask(HK_TYPE_DOMAIN)) |
c744dc4a BM |
1392 | asym_cpu_capacity_update_data(cpu); |
1393 | ||
1394 | list_for_each_entry_safe(entry, next, &asym_cap_list, link) { | |
1395 | if (cpumask_empty(cpu_capacity_span(entry))) { | |
1396 | list_del(&entry->link); | |
1397 | kfree(entry); | |
1398 | } | |
1399 | } | |
1400 | ||
1401 | /* | |
1402 | * Only one capacity value has been detected i.e. this system is symmetric. | |
1403 | * No need to keep this data around. | |
1404 | */ | |
1405 | if (list_is_singular(&asym_cap_list)) { | |
1406 | entry = list_first_entry(&asym_cap_list, typeof(*entry), link); | |
1407 | list_del(&entry->link); | |
1408 | kfree(entry); | |
1409 | } | |
1410 | } | |
1411 | ||
f2cb1360 IM |
1412 | /* |
1413 | * Initializers for schedule domains | |
1414 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
1415 | */ | |
1416 | ||
1417 | static int default_relax_domain_level = -1; | |
1418 | int sched_domain_level_max; | |
1419 | ||
1420 | static int __init setup_relax_domain_level(char *str) | |
1421 | { | |
1422 | if (kstrtoint(str, 0, &default_relax_domain_level)) | |
1423 | pr_warn("Unable to set relax_domain_level\n"); | |
1424 | ||
1425 | return 1; | |
1426 | } | |
1427 | __setup("relax_domain_level=", setup_relax_domain_level); | |
1428 | ||
1429 | static void set_domain_attribute(struct sched_domain *sd, | |
1430 | struct sched_domain_attr *attr) | |
1431 | { | |
1432 | int request; | |
1433 | ||
1434 | if (!attr || attr->relax_domain_level < 0) { | |
1435 | if (default_relax_domain_level < 0) | |
1436 | return; | |
9ae7ab20 | 1437 | request = default_relax_domain_level; |
f2cb1360 IM |
1438 | } else |
1439 | request = attr->relax_domain_level; | |
9ae7ab20 VS |
1440 | |
1441 | if (sd->level > request) { | |
f2cb1360 IM |
1442 | /* Turn off idle balance on this domain: */ |
1443 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); | |
f2cb1360 IM |
1444 | } |
1445 | } | |
1446 | ||
1447 | static void __sdt_free(const struct cpumask *cpu_map); | |
1448 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
1449 | ||
1450 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, | |
1451 | const struct cpumask *cpu_map) | |
1452 | { | |
1453 | switch (what) { | |
1454 | case sa_rootdomain: | |
1455 | if (!atomic_read(&d->rd->refcount)) | |
1456 | free_rootdomain(&d->rd->rcu); | |
df561f66 | 1457 | fallthrough; |
f2cb1360 IM |
1458 | case sa_sd: |
1459 | free_percpu(d->sd); | |
df561f66 | 1460 | fallthrough; |
f2cb1360 IM |
1461 | case sa_sd_storage: |
1462 | __sdt_free(cpu_map); | |
df561f66 | 1463 | fallthrough; |
f2cb1360 IM |
1464 | case sa_none: |
1465 | break; | |
1466 | } | |
1467 | } | |
1468 | ||
1469 | static enum s_alloc | |
1470 | __visit_domain_allocation_hell(struct s_data *d, const struct cpumask *cpu_map) | |
1471 | { | |
1472 | memset(d, 0, sizeof(*d)); | |
1473 | ||
1474 | if (__sdt_alloc(cpu_map)) | |
1475 | return sa_sd_storage; | |
1476 | d->sd = alloc_percpu(struct sched_domain *); | |
1477 | if (!d->sd) | |
1478 | return sa_sd_storage; | |
1479 | d->rd = alloc_rootdomain(); | |
1480 | if (!d->rd) | |
1481 | return sa_sd; | |
97fb7a0a | 1482 | |
f2cb1360 IM |
1483 | return sa_rootdomain; |
1484 | } | |
1485 | ||
1486 | /* | |
1487 | * NULL the sd_data elements we've used to build the sched_domain and | |
1488 | * sched_group structure so that the subsequent __free_domain_allocs() | |
1489 | * will not free the data we're using. | |
1490 | */ | |
1491 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
1492 | { | |
1493 | struct sd_data *sdd = sd->private; | |
1494 | ||
1495 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
1496 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
1497 | ||
1498 | if (atomic_read(&(*per_cpu_ptr(sdd->sds, cpu))->ref)) | |
1499 | *per_cpu_ptr(sdd->sds, cpu) = NULL; | |
1500 | ||
1501 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) | |
1502 | *per_cpu_ptr(sdd->sg, cpu) = NULL; | |
1503 | ||
1504 | if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) | |
1505 | *per_cpu_ptr(sdd->sgc, cpu) = NULL; | |
1506 | } | |
1507 | ||
1508 | #ifdef CONFIG_NUMA | |
f2cb1360 | 1509 | enum numa_topology_type sched_numa_topology_type; |
97fb7a0a IM |
1510 | |
1511 | static int sched_domains_numa_levels; | |
1512 | static int sched_domains_curr_level; | |
1513 | ||
1514 | int sched_max_numa_distance; | |
1515 | static int *sched_domains_numa_distance; | |
1516 | static struct cpumask ***sched_domains_numa_masks; | |
f2cb1360 IM |
1517 | #endif |
1518 | ||
1519 | /* | |
1520 | * SD_flags allowed in topology descriptions. | |
1521 | * | |
1522 | * These flags are purely descriptive of the topology and do not prescribe | |
1523 | * behaviour. Behaviour is artificial and mapped in the below sd_init() | |
1524 | * function: | |
1525 | * | |
1526 | * SD_SHARE_CPUCAPACITY - describes SMT topologies | |
1527 | * SD_SHARE_PKG_RESOURCES - describes shared caches | |
1528 | * SD_NUMA - describes NUMA topologies | |
f2cb1360 IM |
1529 | * |
1530 | * Odd one out, which beside describing the topology has a quirk also | |
1531 | * prescribes the desired behaviour that goes along with it: | |
1532 | * | |
1533 | * SD_ASYM_PACKING - describes SMT quirks | |
1534 | */ | |
1535 | #define TOPOLOGY_SD_FLAGS \ | |
97fb7a0a | 1536 | (SD_SHARE_CPUCAPACITY | \ |
f2cb1360 | 1537 | SD_SHARE_PKG_RESOURCES | \ |
97fb7a0a | 1538 | SD_NUMA | \ |
cfe7ddcb | 1539 | SD_ASYM_PACKING) |
f2cb1360 IM |
1540 | |
1541 | static struct sched_domain * | |
1542 | sd_init(struct sched_domain_topology_level *tl, | |
1543 | const struct cpumask *cpu_map, | |
c744dc4a | 1544 | struct sched_domain *child, int cpu) |
f2cb1360 IM |
1545 | { |
1546 | struct sd_data *sdd = &tl->data; | |
1547 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); | |
1548 | int sd_id, sd_weight, sd_flags = 0; | |
c744dc4a | 1549 | struct cpumask *sd_span; |
f2cb1360 IM |
1550 | |
1551 | #ifdef CONFIG_NUMA | |
1552 | /* | |
1553 | * Ugly hack to pass state to sd_numa_mask()... | |
1554 | */ | |
1555 | sched_domains_curr_level = tl->numa_level; | |
1556 | #endif | |
1557 | ||
1558 | sd_weight = cpumask_weight(tl->mask(cpu)); | |
1559 | ||
1560 | if (tl->sd_flags) | |
1561 | sd_flags = (*tl->sd_flags)(); | |
1562 | if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS, | |
1563 | "wrong sd_flags in topology description\n")) | |
9b1b234b | 1564 | sd_flags &= TOPOLOGY_SD_FLAGS; |
f2cb1360 IM |
1565 | |
1566 | *sd = (struct sched_domain){ | |
1567 | .min_interval = sd_weight, | |
1568 | .max_interval = 2*sd_weight, | |
6e749913 | 1569 | .busy_factor = 16, |
2208cdaa | 1570 | .imbalance_pct = 117, |
f2cb1360 IM |
1571 | |
1572 | .cache_nice_tries = 0, | |
f2cb1360 | 1573 | |
36c5bdc4 | 1574 | .flags = 1*SD_BALANCE_NEWIDLE |
f2cb1360 IM |
1575 | | 1*SD_BALANCE_EXEC |
1576 | | 1*SD_BALANCE_FORK | |
1577 | | 0*SD_BALANCE_WAKE | |
1578 | | 1*SD_WAKE_AFFINE | |
1579 | | 0*SD_SHARE_CPUCAPACITY | |
1580 | | 0*SD_SHARE_PKG_RESOURCES | |
1581 | | 0*SD_SERIALIZE | |
9c63e84d | 1582 | | 1*SD_PREFER_SIBLING |
f2cb1360 IM |
1583 | | 0*SD_NUMA |
1584 | | sd_flags | |
1585 | , | |
1586 | ||
1587 | .last_balance = jiffies, | |
1588 | .balance_interval = sd_weight, | |
f2cb1360 | 1589 | .max_newidle_lb_cost = 0, |
e60b56e4 | 1590 | .last_decay_max_lb_cost = jiffies, |
f2cb1360 IM |
1591 | .child = child, |
1592 | #ifdef CONFIG_SCHED_DEBUG | |
1593 | .name = tl->name, | |
1594 | #endif | |
1595 | }; | |
1596 | ||
c744dc4a BM |
1597 | sd_span = sched_domain_span(sd); |
1598 | cpumask_and(sd_span, cpu_map, tl->mask(cpu)); | |
1599 | sd_id = cpumask_first(sd_span); | |
1600 | ||
1601 | sd->flags |= asym_cpu_capacity_classify(sd_span, cpu_map); | |
1602 | ||
1603 | WARN_ONCE((sd->flags & (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY)) == | |
1604 | (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY), | |
1605 | "CPU capacity asymmetry not supported on SMT\n"); | |
f2cb1360 IM |
1606 | |
1607 | /* | |
1608 | * Convert topological properties into behaviour. | |
1609 | */ | |
a526d466 MR |
1610 | /* Don't attempt to spread across CPUs of different capacities. */ |
1611 | if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child) | |
1612 | sd->child->flags &= ~SD_PREFER_SIBLING; | |
f2cb1360 IM |
1613 | |
1614 | if (sd->flags & SD_SHARE_CPUCAPACITY) { | |
f2cb1360 | 1615 | sd->imbalance_pct = 110; |
f2cb1360 IM |
1616 | |
1617 | } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { | |
1618 | sd->imbalance_pct = 117; | |
1619 | sd->cache_nice_tries = 1; | |
f2cb1360 IM |
1620 | |
1621 | #ifdef CONFIG_NUMA | |
1622 | } else if (sd->flags & SD_NUMA) { | |
1623 | sd->cache_nice_tries = 2; | |
f2cb1360 | 1624 | |
9c63e84d | 1625 | sd->flags &= ~SD_PREFER_SIBLING; |
f2cb1360 | 1626 | sd->flags |= SD_SERIALIZE; |
a55c7454 | 1627 | if (sched_domains_numa_distance[tl->numa_level] > node_reclaim_distance) { |
f2cb1360 IM |
1628 | sd->flags &= ~(SD_BALANCE_EXEC | |
1629 | SD_BALANCE_FORK | | |
1630 | SD_WAKE_AFFINE); | |
1631 | } | |
1632 | ||
1633 | #endif | |
1634 | } else { | |
f2cb1360 | 1635 | sd->cache_nice_tries = 1; |
f2cb1360 IM |
1636 | } |
1637 | ||
1638 | /* | |
1639 | * For all levels sharing cache; connect a sched_domain_shared | |
1640 | * instance. | |
1641 | */ | |
1642 | if (sd->flags & SD_SHARE_PKG_RESOURCES) { | |
1643 | sd->shared = *per_cpu_ptr(sdd->sds, sd_id); | |
1644 | atomic_inc(&sd->shared->ref); | |
1645 | atomic_set(&sd->shared->nr_busy_cpus, sd_weight); | |
1646 | } | |
1647 | ||
1648 | sd->private = sdd; | |
1649 | ||
1650 | return sd; | |
1651 | } | |
1652 | ||
1653 | /* | |
1654 | * Topology list, bottom-up. | |
1655 | */ | |
1656 | static struct sched_domain_topology_level default_topology[] = { | |
1657 | #ifdef CONFIG_SCHED_SMT | |
1658 | { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, | |
1659 | #endif | |
778c558f BS |
1660 | |
1661 | #ifdef CONFIG_SCHED_CLUSTER | |
1662 | { cpu_clustergroup_mask, cpu_cluster_flags, SD_INIT_NAME(CLS) }, | |
1663 | #endif | |
1664 | ||
f2cb1360 IM |
1665 | #ifdef CONFIG_SCHED_MC |
1666 | { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, | |
1667 | #endif | |
1668 | { cpu_cpu_mask, SD_INIT_NAME(DIE) }, | |
1669 | { NULL, }, | |
1670 | }; | |
1671 | ||
1672 | static struct sched_domain_topology_level *sched_domain_topology = | |
1673 | default_topology; | |
0fb3978b | 1674 | static struct sched_domain_topology_level *sched_domain_topology_saved; |
f2cb1360 IM |
1675 | |
1676 | #define for_each_sd_topology(tl) \ | |
1677 | for (tl = sched_domain_topology; tl->mask; tl++) | |
1678 | ||
1679 | void set_sched_topology(struct sched_domain_topology_level *tl) | |
1680 | { | |
1681 | if (WARN_ON_ONCE(sched_smp_initialized)) | |
1682 | return; | |
1683 | ||
1684 | sched_domain_topology = tl; | |
0fb3978b | 1685 | sched_domain_topology_saved = NULL; |
f2cb1360 IM |
1686 | } |
1687 | ||
1688 | #ifdef CONFIG_NUMA | |
1689 | ||
1690 | static const struct cpumask *sd_numa_mask(int cpu) | |
1691 | { | |
1692 | return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; | |
1693 | } | |
1694 | ||
1695 | static void sched_numa_warn(const char *str) | |
1696 | { | |
1697 | static int done = false; | |
1698 | int i,j; | |
1699 | ||
1700 | if (done) | |
1701 | return; | |
1702 | ||
1703 | done = true; | |
1704 | ||
1705 | printk(KERN_WARNING "ERROR: %s\n\n", str); | |
1706 | ||
1707 | for (i = 0; i < nr_node_ids; i++) { | |
1708 | printk(KERN_WARNING " "); | |
0fb3978b HY |
1709 | for (j = 0; j < nr_node_ids; j++) { |
1710 | if (!node_state(i, N_CPU) || !node_state(j, N_CPU)) | |
1711 | printk(KERN_CONT "(%02d) ", node_distance(i,j)); | |
1712 | else | |
1713 | printk(KERN_CONT " %02d ", node_distance(i,j)); | |
1714 | } | |
f2cb1360 IM |
1715 | printk(KERN_CONT "\n"); |
1716 | } | |
1717 | printk(KERN_WARNING "\n"); | |
1718 | } | |
1719 | ||
1720 | bool find_numa_distance(int distance) | |
1721 | { | |
0fb3978b HY |
1722 | bool found = false; |
1723 | int i, *distances; | |
f2cb1360 IM |
1724 | |
1725 | if (distance == node_distance(0, 0)) | |
1726 | return true; | |
1727 | ||
0fb3978b HY |
1728 | rcu_read_lock(); |
1729 | distances = rcu_dereference(sched_domains_numa_distance); | |
1730 | if (!distances) | |
1731 | goto unlock; | |
f2cb1360 | 1732 | for (i = 0; i < sched_domains_numa_levels; i++) { |
0fb3978b HY |
1733 | if (distances[i] == distance) { |
1734 | found = true; | |
1735 | break; | |
1736 | } | |
f2cb1360 | 1737 | } |
0fb3978b HY |
1738 | unlock: |
1739 | rcu_read_unlock(); | |
f2cb1360 | 1740 | |
0fb3978b | 1741 | return found; |
f2cb1360 IM |
1742 | } |
1743 | ||
0fb3978b HY |
1744 | #define for_each_cpu_node_but(n, nbut) \ |
1745 | for_each_node_state(n, N_CPU) \ | |
1746 | if (n == nbut) \ | |
1747 | continue; \ | |
1748 | else | |
1749 | ||
f2cb1360 IM |
1750 | /* |
1751 | * A system can have three types of NUMA topology: | |
1752 | * NUMA_DIRECT: all nodes are directly connected, or not a NUMA system | |
1753 | * NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes | |
1754 | * NUMA_BACKPLANE: nodes can reach other nodes through a backplane | |
1755 | * | |
1756 | * The difference between a glueless mesh topology and a backplane | |
1757 | * topology lies in whether communication between not directly | |
1758 | * connected nodes goes through intermediary nodes (where programs | |
1759 | * could run), or through backplane controllers. This affects | |
1760 | * placement of programs. | |
1761 | * | |
1762 | * The type of topology can be discerned with the following tests: | |
1763 | * - If the maximum distance between any nodes is 1 hop, the system | |
1764 | * is directly connected. | |
1765 | * - If for two nodes A and B, located N > 1 hops away from each other, | |
1766 | * there is an intermediary node C, which is < N hops away from both | |
1767 | * nodes A and B, the system is a glueless mesh. | |
1768 | */ | |
0fb3978b | 1769 | static void init_numa_topology_type(int offline_node) |
f2cb1360 IM |
1770 | { |
1771 | int a, b, c, n; | |
1772 | ||
1773 | n = sched_max_numa_distance; | |
1774 | ||
e5e96faf | 1775 | if (sched_domains_numa_levels <= 2) { |
f2cb1360 IM |
1776 | sched_numa_topology_type = NUMA_DIRECT; |
1777 | return; | |
1778 | } | |
1779 | ||
0fb3978b HY |
1780 | for_each_cpu_node_but(a, offline_node) { |
1781 | for_each_cpu_node_but(b, offline_node) { | |
f2cb1360 IM |
1782 | /* Find two nodes furthest removed from each other. */ |
1783 | if (node_distance(a, b) < n) | |
1784 | continue; | |
1785 | ||
1786 | /* Is there an intermediary node between a and b? */ | |
0fb3978b | 1787 | for_each_cpu_node_but(c, offline_node) { |
f2cb1360 IM |
1788 | if (node_distance(a, c) < n && |
1789 | node_distance(b, c) < n) { | |
1790 | sched_numa_topology_type = | |
1791 | NUMA_GLUELESS_MESH; | |
1792 | return; | |
1793 | } | |
1794 | } | |
1795 | ||
1796 | sched_numa_topology_type = NUMA_BACKPLANE; | |
1797 | return; | |
1798 | } | |
1799 | } | |
0fb3978b HY |
1800 | |
1801 | pr_err("Failed to find a NUMA topology type, defaulting to DIRECT\n"); | |
1802 | sched_numa_topology_type = NUMA_DIRECT; | |
f2cb1360 IM |
1803 | } |
1804 | ||
620a6dc4 VS |
1805 | |
1806 | #define NR_DISTANCE_VALUES (1 << DISTANCE_BITS) | |
1807 | ||
0fb3978b | 1808 | void sched_init_numa(int offline_node) |
f2cb1360 | 1809 | { |
f2cb1360 | 1810 | struct sched_domain_topology_level *tl; |
620a6dc4 VS |
1811 | unsigned long *distance_map; |
1812 | int nr_levels = 0; | |
1813 | int i, j; | |
0fb3978b HY |
1814 | int *distances; |
1815 | struct cpumask ***masks; | |
051f3ca0 | 1816 | |
f2cb1360 IM |
1817 | /* |
1818 | * O(nr_nodes^2) deduplicating selection sort -- in order to find the | |
1819 | * unique distances in the node_distance() table. | |
f2cb1360 | 1820 | */ |
620a6dc4 VS |
1821 | distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL); |
1822 | if (!distance_map) | |
1823 | return; | |
1824 | ||
1825 | bitmap_zero(distance_map, NR_DISTANCE_VALUES); | |
0fb3978b HY |
1826 | for_each_cpu_node_but(i, offline_node) { |
1827 | for_each_cpu_node_but(j, offline_node) { | |
620a6dc4 | 1828 | int distance = node_distance(i, j); |
f2cb1360 | 1829 | |
620a6dc4 VS |
1830 | if (distance < LOCAL_DISTANCE || distance >= NR_DISTANCE_VALUES) { |
1831 | sched_numa_warn("Invalid distance value range"); | |
0fb3978b | 1832 | bitmap_free(distance_map); |
620a6dc4 | 1833 | return; |
f2cb1360 | 1834 | } |
620a6dc4 VS |
1835 | |
1836 | bitmap_set(distance_map, distance, 1); | |
f2cb1360 | 1837 | } |
620a6dc4 VS |
1838 | } |
1839 | /* | |
1840 | * We can now figure out how many unique distance values there are and | |
1841 | * allocate memory accordingly. | |
1842 | */ | |
1843 | nr_levels = bitmap_weight(distance_map, NR_DISTANCE_VALUES); | |
f2cb1360 | 1844 | |
0fb3978b HY |
1845 | distances = kcalloc(nr_levels, sizeof(int), GFP_KERNEL); |
1846 | if (!distances) { | |
620a6dc4 VS |
1847 | bitmap_free(distance_map); |
1848 | return; | |
f2cb1360 IM |
1849 | } |
1850 | ||
620a6dc4 VS |
1851 | for (i = 0, j = 0; i < nr_levels; i++, j++) { |
1852 | j = find_next_bit(distance_map, NR_DISTANCE_VALUES, j); | |
0fb3978b | 1853 | distances[i] = j; |
620a6dc4 | 1854 | } |
0fb3978b | 1855 | rcu_assign_pointer(sched_domains_numa_distance, distances); |
620a6dc4 VS |
1856 | |
1857 | bitmap_free(distance_map); | |
1858 | ||
f2cb1360 | 1859 | /* |
620a6dc4 | 1860 | * 'nr_levels' contains the number of unique distances |
f2cb1360 IM |
1861 | * |
1862 | * The sched_domains_numa_distance[] array includes the actual distance | |
1863 | * numbers. | |
1864 | */ | |
1865 | ||
1866 | /* | |
1867 | * Here, we should temporarily reset sched_domains_numa_levels to 0. | |
1868 | * If it fails to allocate memory for array sched_domains_numa_masks[][], | |
620a6dc4 | 1869 | * the array will contain less then 'nr_levels' members. This could be |
f2cb1360 IM |
1870 | * dangerous when we use it to iterate array sched_domains_numa_masks[][] |
1871 | * in other functions. | |
1872 | * | |
620a6dc4 | 1873 | * We reset it to 'nr_levels' at the end of this function. |
f2cb1360 IM |
1874 | */ |
1875 | sched_domains_numa_levels = 0; | |
1876 | ||
0fb3978b HY |
1877 | masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL); |
1878 | if (!masks) | |
f2cb1360 IM |
1879 | return; |
1880 | ||
1881 | /* | |
1882 | * Now for each level, construct a mask per node which contains all | |
1883 | * CPUs of nodes that are that many hops away from us. | |
1884 | */ | |
620a6dc4 | 1885 | for (i = 0; i < nr_levels; i++) { |
0fb3978b HY |
1886 | masks[i] = kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); |
1887 | if (!masks[i]) | |
f2cb1360 IM |
1888 | return; |
1889 | ||
0fb3978b | 1890 | for_each_cpu_node_but(j, offline_node) { |
f2cb1360 | 1891 | struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
620a6dc4 VS |
1892 | int k; |
1893 | ||
f2cb1360 IM |
1894 | if (!mask) |
1895 | return; | |
1896 | ||
0fb3978b | 1897 | masks[i][j] = mask; |
0083242c | 1898 | |
0fb3978b | 1899 | for_each_cpu_node_but(k, offline_node) { |
620a6dc4 VS |
1900 | if (sched_debug() && (node_distance(j, k) != node_distance(k, j))) |
1901 | sched_numa_warn("Node-distance not symmetric"); | |
1902 | ||
f2cb1360 IM |
1903 | if (node_distance(j, k) > sched_domains_numa_distance[i]) |
1904 | continue; | |
1905 | ||
1906 | cpumask_or(mask, mask, cpumask_of_node(k)); | |
1907 | } | |
1908 | } | |
1909 | } | |
0fb3978b | 1910 | rcu_assign_pointer(sched_domains_numa_masks, masks); |
f2cb1360 IM |
1911 | |
1912 | /* Compute default topology size */ | |
1913 | for (i = 0; sched_domain_topology[i].mask; i++); | |
1914 | ||
71e5f664 | 1915 | tl = kzalloc((i + nr_levels + 1) * |
f2cb1360 IM |
1916 | sizeof(struct sched_domain_topology_level), GFP_KERNEL); |
1917 | if (!tl) | |
1918 | return; | |
1919 | ||
1920 | /* | |
1921 | * Copy the default topology bits.. | |
1922 | */ | |
1923 | for (i = 0; sched_domain_topology[i].mask; i++) | |
1924 | tl[i] = sched_domain_topology[i]; | |
1925 | ||
051f3ca0 SS |
1926 | /* |
1927 | * Add the NUMA identity distance, aka single NODE. | |
1928 | */ | |
1929 | tl[i++] = (struct sched_domain_topology_level){ | |
1930 | .mask = sd_numa_mask, | |
1931 | .numa_level = 0, | |
1932 | SD_INIT_NAME(NODE) | |
1933 | }; | |
1934 | ||
f2cb1360 IM |
1935 | /* |
1936 | * .. and append 'j' levels of NUMA goodness. | |
1937 | */ | |
620a6dc4 | 1938 | for (j = 1; j < nr_levels; i++, j++) { |
f2cb1360 IM |
1939 | tl[i] = (struct sched_domain_topology_level){ |
1940 | .mask = sd_numa_mask, | |
1941 | .sd_flags = cpu_numa_flags, | |
1942 | .flags = SDTL_OVERLAP, | |
1943 | .numa_level = j, | |
1944 | SD_INIT_NAME(NUMA) | |
1945 | }; | |
1946 | } | |
1947 | ||
0fb3978b | 1948 | sched_domain_topology_saved = sched_domain_topology; |
f2cb1360 IM |
1949 | sched_domain_topology = tl; |
1950 | ||
620a6dc4 | 1951 | sched_domains_numa_levels = nr_levels; |
0fb3978b | 1952 | WRITE_ONCE(sched_max_numa_distance, sched_domains_numa_distance[nr_levels - 1]); |
0083242c | 1953 | |
0fb3978b | 1954 | init_numa_topology_type(offline_node); |
0083242c VS |
1955 | } |
1956 | ||
0083242c | 1957 | |
0fb3978b HY |
1958 | static void sched_reset_numa(void) |
1959 | { | |
1960 | int nr_levels, *distances; | |
1961 | struct cpumask ***masks; | |
0083242c | 1962 | |
0fb3978b HY |
1963 | nr_levels = sched_domains_numa_levels; |
1964 | sched_domains_numa_levels = 0; | |
1965 | sched_max_numa_distance = 0; | |
1966 | sched_numa_topology_type = NUMA_DIRECT; | |
1967 | distances = sched_domains_numa_distance; | |
1968 | rcu_assign_pointer(sched_domains_numa_distance, NULL); | |
1969 | masks = sched_domains_numa_masks; | |
1970 | rcu_assign_pointer(sched_domains_numa_masks, NULL); | |
1971 | if (distances || masks) { | |
1972 | int i, j; | |
1973 | ||
1974 | synchronize_rcu(); | |
1975 | kfree(distances); | |
1976 | for (i = 0; i < nr_levels && masks; i++) { | |
1977 | if (!masks[i]) | |
0083242c | 1978 | continue; |
0fb3978b HY |
1979 | for_each_node(j) |
1980 | kfree(masks[i][j]); | |
1981 | kfree(masks[i]); | |
0083242c | 1982 | } |
0fb3978b | 1983 | kfree(masks); |
0083242c | 1984 | } |
0fb3978b HY |
1985 | if (sched_domain_topology_saved) { |
1986 | kfree(sched_domain_topology); | |
1987 | sched_domain_topology = sched_domain_topology_saved; | |
1988 | sched_domain_topology_saved = NULL; | |
1989 | } | |
1990 | } | |
1991 | ||
1992 | /* | |
1993 | * Call with hotplug lock held | |
1994 | */ | |
1995 | void sched_update_numa(int cpu, bool online) | |
1996 | { | |
1997 | int node; | |
0083242c | 1998 | |
0fb3978b | 1999 | node = cpu_to_node(cpu); |
0083242c | 2000 | /* |
0fb3978b HY |
2001 | * Scheduler NUMA topology is updated when the first CPU of a |
2002 | * node is onlined or the last CPU of a node is offlined. | |
0083242c | 2003 | */ |
0fb3978b HY |
2004 | if (cpumask_weight(cpumask_of_node(node)) != 1) |
2005 | return; | |
2006 | ||
2007 | sched_reset_numa(); | |
2008 | sched_init_numa(online ? NUMA_NO_NODE : node); | |
f2cb1360 IM |
2009 | } |
2010 | ||
2011 | void sched_domains_numa_masks_set(unsigned int cpu) | |
2012 | { | |
2013 | int node = cpu_to_node(cpu); | |
2014 | int i, j; | |
2015 | ||
2016 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
2017 | for (j = 0; j < nr_node_ids; j++) { | |
0fb3978b | 2018 | if (!node_state(j, N_CPU)) |
0083242c VS |
2019 | continue; |
2020 | ||
2021 | /* Set ourselves in the remote node's masks */ | |
f2cb1360 IM |
2022 | if (node_distance(j, node) <= sched_domains_numa_distance[i]) |
2023 | cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); | |
2024 | } | |
2025 | } | |
2026 | } | |
2027 | ||
2028 | void sched_domains_numa_masks_clear(unsigned int cpu) | |
2029 | { | |
2030 | int i, j; | |
2031 | ||
2032 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
0fb3978b HY |
2033 | for (j = 0; j < nr_node_ids; j++) { |
2034 | if (sched_domains_numa_masks[i][j]) | |
2035 | cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); | |
2036 | } | |
f2cb1360 IM |
2037 | } |
2038 | } | |
2039 | ||
e0e8d491 WL |
2040 | /* |
2041 | * sched_numa_find_closest() - given the NUMA topology, find the cpu | |
2042 | * closest to @cpu from @cpumask. | |
2043 | * cpumask: cpumask to find a cpu from | |
2044 | * cpu: cpu to be close to | |
2045 | * | |
2046 | * returns: cpu, or nr_cpu_ids when nothing found. | |
2047 | */ | |
2048 | int sched_numa_find_closest(const struct cpumask *cpus, int cpu) | |
2049 | { | |
0fb3978b HY |
2050 | int i, j = cpu_to_node(cpu), found = nr_cpu_ids; |
2051 | struct cpumask ***masks; | |
e0e8d491 | 2052 | |
0fb3978b HY |
2053 | rcu_read_lock(); |
2054 | masks = rcu_dereference(sched_domains_numa_masks); | |
2055 | if (!masks) | |
2056 | goto unlock; | |
e0e8d491 | 2057 | for (i = 0; i < sched_domains_numa_levels; i++) { |
0fb3978b HY |
2058 | if (!masks[i][j]) |
2059 | break; | |
2060 | cpu = cpumask_any_and(cpus, masks[i][j]); | |
2061 | if (cpu < nr_cpu_ids) { | |
2062 | found = cpu; | |
2063 | break; | |
2064 | } | |
e0e8d491 | 2065 | } |
0fb3978b HY |
2066 | unlock: |
2067 | rcu_read_unlock(); | |
2068 | ||
2069 | return found; | |
e0e8d491 WL |
2070 | } |
2071 | ||
cd7f5535 YN |
2072 | struct __cmp_key { |
2073 | const struct cpumask *cpus; | |
2074 | struct cpumask ***masks; | |
2075 | int node; | |
2076 | int cpu; | |
2077 | int w; | |
2078 | }; | |
2079 | ||
2080 | static int hop_cmp(const void *a, const void *b) | |
2081 | { | |
01bb11ad | 2082 | struct cpumask **prev_hop, **cur_hop = *(struct cpumask ***)b; |
cd7f5535 YN |
2083 | struct __cmp_key *k = (struct __cmp_key *)a; |
2084 | ||
2085 | if (cpumask_weight_and(k->cpus, cur_hop[k->node]) <= k->cpu) | |
2086 | return 1; | |
2087 | ||
01bb11ad YN |
2088 | if (b == k->masks) { |
2089 | k->w = 0; | |
2090 | return 0; | |
2091 | } | |
2092 | ||
2093 | prev_hop = *((struct cpumask ***)b - 1); | |
2094 | k->w = cpumask_weight_and(k->cpus, prev_hop[k->node]); | |
cd7f5535 YN |
2095 | if (k->w <= k->cpu) |
2096 | return 0; | |
2097 | ||
2098 | return -1; | |
2099 | } | |
2100 | ||
2101 | /* | |
2102 | * sched_numa_find_nth_cpu() - given the NUMA topology, find the Nth next cpu | |
2103 | * closest to @cpu from @cpumask. | |
2104 | * cpumask: cpumask to find a cpu from | |
2105 | * cpu: Nth cpu to find | |
2106 | * | |
2107 | * returns: cpu, or nr_cpu_ids when nothing found. | |
2108 | */ | |
2109 | int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node) | |
2110 | { | |
2111 | struct __cmp_key k = { .cpus = cpus, .node = node, .cpu = cpu }; | |
2112 | struct cpumask ***hop_masks; | |
2113 | int hop, ret = nr_cpu_ids; | |
2114 | ||
2115 | rcu_read_lock(); | |
2116 | ||
2117 | k.masks = rcu_dereference(sched_domains_numa_masks); | |
2118 | if (!k.masks) | |
2119 | goto unlock; | |
2120 | ||
2121 | hop_masks = bsearch(&k, k.masks, sched_domains_numa_levels, sizeof(k.masks[0]), hop_cmp); | |
2122 | hop = hop_masks - k.masks; | |
2123 | ||
2124 | ret = hop ? | |
2125 | cpumask_nth_and_andnot(cpu - k.w, cpus, k.masks[hop][node], k.masks[hop-1][node]) : | |
2126 | cpumask_nth_and(cpu, cpus, k.masks[0][node]); | |
2127 | unlock: | |
2128 | rcu_read_unlock(); | |
2129 | return ret; | |
2130 | } | |
2131 | EXPORT_SYMBOL_GPL(sched_numa_find_nth_cpu); | |
9feae658 VS |
2132 | |
2133 | /** | |
2134 | * sched_numa_hop_mask() - Get the cpumask of CPUs at most @hops hops away from | |
2135 | * @node | |
2136 | * @node: The node to count hops from. | |
2137 | * @hops: Include CPUs up to that many hops away. 0 means local node. | |
2138 | * | |
2139 | * Return: On success, a pointer to a cpumask of CPUs at most @hops away from | |
2140 | * @node, an error value otherwise. | |
2141 | * | |
2142 | * Requires rcu_lock to be held. Returned cpumask is only valid within that | |
2143 | * read-side section, copy it if required beyond that. | |
2144 | * | |
2145 | * Note that not all hops are equal in distance; see sched_init_numa() for how | |
2146 | * distances and masks are handled. | |
2147 | * Also note that this is a reflection of sched_domains_numa_masks, which may change | |
2148 | * during the lifetime of the system (offline nodes are taken out of the masks). | |
2149 | */ | |
2150 | const struct cpumask *sched_numa_hop_mask(unsigned int node, unsigned int hops) | |
2151 | { | |
2152 | struct cpumask ***masks; | |
2153 | ||
2154 | if (node >= nr_node_ids || hops >= sched_domains_numa_levels) | |
2155 | return ERR_PTR(-EINVAL); | |
2156 | ||
2157 | masks = rcu_dereference(sched_domains_numa_masks); | |
2158 | if (!masks) | |
2159 | return ERR_PTR(-EBUSY); | |
2160 | ||
2161 | return masks[hops][node]; | |
2162 | } | |
2163 | EXPORT_SYMBOL_GPL(sched_numa_hop_mask); | |
2164 | ||
f2cb1360 IM |
2165 | #endif /* CONFIG_NUMA */ |
2166 | ||
2167 | static int __sdt_alloc(const struct cpumask *cpu_map) | |
2168 | { | |
2169 | struct sched_domain_topology_level *tl; | |
2170 | int j; | |
2171 | ||
2172 | for_each_sd_topology(tl) { | |
2173 | struct sd_data *sdd = &tl->data; | |
2174 | ||
2175 | sdd->sd = alloc_percpu(struct sched_domain *); | |
2176 | if (!sdd->sd) | |
2177 | return -ENOMEM; | |
2178 | ||
2179 | sdd->sds = alloc_percpu(struct sched_domain_shared *); | |
2180 | if (!sdd->sds) | |
2181 | return -ENOMEM; | |
2182 | ||
2183 | sdd->sg = alloc_percpu(struct sched_group *); | |
2184 | if (!sdd->sg) | |
2185 | return -ENOMEM; | |
2186 | ||
2187 | sdd->sgc = alloc_percpu(struct sched_group_capacity *); | |
2188 | if (!sdd->sgc) | |
2189 | return -ENOMEM; | |
2190 | ||
2191 | for_each_cpu(j, cpu_map) { | |
2192 | struct sched_domain *sd; | |
2193 | struct sched_domain_shared *sds; | |
2194 | struct sched_group *sg; | |
2195 | struct sched_group_capacity *sgc; | |
2196 | ||
2197 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
2198 | GFP_KERNEL, cpu_to_node(j)); | |
2199 | if (!sd) | |
2200 | return -ENOMEM; | |
2201 | ||
2202 | *per_cpu_ptr(sdd->sd, j) = sd; | |
2203 | ||
2204 | sds = kzalloc_node(sizeof(struct sched_domain_shared), | |
2205 | GFP_KERNEL, cpu_to_node(j)); | |
2206 | if (!sds) | |
2207 | return -ENOMEM; | |
2208 | ||
2209 | *per_cpu_ptr(sdd->sds, j) = sds; | |
2210 | ||
2211 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
2212 | GFP_KERNEL, cpu_to_node(j)); | |
2213 | if (!sg) | |
2214 | return -ENOMEM; | |
2215 | ||
2216 | sg->next = sg; | |
2217 | ||
2218 | *per_cpu_ptr(sdd->sg, j) = sg; | |
2219 | ||
2220 | sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), | |
2221 | GFP_KERNEL, cpu_to_node(j)); | |
2222 | if (!sgc) | |
2223 | return -ENOMEM; | |
2224 | ||
005f874d PZ |
2225 | #ifdef CONFIG_SCHED_DEBUG |
2226 | sgc->id = j; | |
2227 | #endif | |
2228 | ||
f2cb1360 IM |
2229 | *per_cpu_ptr(sdd->sgc, j) = sgc; |
2230 | } | |
2231 | } | |
2232 | ||
2233 | return 0; | |
2234 | } | |
2235 | ||
2236 | static void __sdt_free(const struct cpumask *cpu_map) | |
2237 | { | |
2238 | struct sched_domain_topology_level *tl; | |
2239 | int j; | |
2240 | ||
2241 | for_each_sd_topology(tl) { | |
2242 | struct sd_data *sdd = &tl->data; | |
2243 | ||
2244 | for_each_cpu(j, cpu_map) { | |
2245 | struct sched_domain *sd; | |
2246 | ||
2247 | if (sdd->sd) { | |
2248 | sd = *per_cpu_ptr(sdd->sd, j); | |
2249 | if (sd && (sd->flags & SD_OVERLAP)) | |
2250 | free_sched_groups(sd->groups, 0); | |
2251 | kfree(*per_cpu_ptr(sdd->sd, j)); | |
2252 | } | |
2253 | ||
2254 | if (sdd->sds) | |
2255 | kfree(*per_cpu_ptr(sdd->sds, j)); | |
2256 | if (sdd->sg) | |
2257 | kfree(*per_cpu_ptr(sdd->sg, j)); | |
2258 | if (sdd->sgc) | |
2259 | kfree(*per_cpu_ptr(sdd->sgc, j)); | |
2260 | } | |
2261 | free_percpu(sdd->sd); | |
2262 | sdd->sd = NULL; | |
2263 | free_percpu(sdd->sds); | |
2264 | sdd->sds = NULL; | |
2265 | free_percpu(sdd->sg); | |
2266 | sdd->sg = NULL; | |
2267 | free_percpu(sdd->sgc); | |
2268 | sdd->sgc = NULL; | |
2269 | } | |
2270 | } | |
2271 | ||
181a80d1 | 2272 | static struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
f2cb1360 | 2273 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, |
c744dc4a | 2274 | struct sched_domain *child, int cpu) |
f2cb1360 | 2275 | { |
c744dc4a | 2276 | struct sched_domain *sd = sd_init(tl, cpu_map, child, cpu); |
f2cb1360 IM |
2277 | |
2278 | if (child) { | |
2279 | sd->level = child->level + 1; | |
2280 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
2281 | child->parent = sd; | |
2282 | ||
2283 | if (!cpumask_subset(sched_domain_span(child), | |
2284 | sched_domain_span(sd))) { | |
2285 | pr_err("BUG: arch topology borken\n"); | |
2286 | #ifdef CONFIG_SCHED_DEBUG | |
2287 | pr_err(" the %s domain not a subset of the %s domain\n", | |
2288 | child->name, sd->name); | |
2289 | #endif | |
97fb7a0a | 2290 | /* Fixup, ensure @sd has at least @child CPUs. */ |
f2cb1360 IM |
2291 | cpumask_or(sched_domain_span(sd), |
2292 | sched_domain_span(sd), | |
2293 | sched_domain_span(child)); | |
2294 | } | |
2295 | ||
2296 | } | |
2297 | set_domain_attribute(sd, attr); | |
2298 | ||
2299 | return sd; | |
2300 | } | |
2301 | ||
ccf74128 VS |
2302 | /* |
2303 | * Ensure topology masks are sane, i.e. there are no conflicts (overlaps) for | |
2304 | * any two given CPUs at this (non-NUMA) topology level. | |
2305 | */ | |
2306 | static bool topology_span_sane(struct sched_domain_topology_level *tl, | |
2307 | const struct cpumask *cpu_map, int cpu) | |
2308 | { | |
2309 | int i; | |
2310 | ||
2311 | /* NUMA levels are allowed to overlap */ | |
2312 | if (tl->flags & SDTL_OVERLAP) | |
2313 | return true; | |
2314 | ||
2315 | /* | |
2316 | * Non-NUMA levels cannot partially overlap - they must be either | |
2317 | * completely equal or completely disjoint. Otherwise we can end up | |
2318 | * breaking the sched_group lists - i.e. a later get_group() pass | |
2319 | * breaks the linking done for an earlier span. | |
2320 | */ | |
2321 | for_each_cpu(i, cpu_map) { | |
2322 | if (i == cpu) | |
2323 | continue; | |
2324 | /* | |
2325 | * We should 'and' all those masks with 'cpu_map' to exactly | |
2326 | * match the topology we're about to build, but that can only | |
2327 | * remove CPUs, which only lessens our ability to detect | |
2328 | * overlaps | |
2329 | */ | |
2330 | if (!cpumask_equal(tl->mask(cpu), tl->mask(i)) && | |
2331 | cpumask_intersects(tl->mask(cpu), tl->mask(i))) | |
2332 | return false; | |
2333 | } | |
2334 | ||
2335 | return true; | |
2336 | } | |
2337 | ||
f2cb1360 IM |
2338 | /* |
2339 | * Build sched domains for a given set of CPUs and attach the sched domains | |
2340 | * to the individual CPUs | |
2341 | */ | |
2342 | static int | |
2343 | build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *attr) | |
2344 | { | |
cd1cb335 | 2345 | enum s_alloc alloc_state = sa_none; |
f2cb1360 IM |
2346 | struct sched_domain *sd; |
2347 | struct s_data d; | |
2348 | struct rq *rq = NULL; | |
2349 | int i, ret = -ENOMEM; | |
df054e84 | 2350 | bool has_asym = false; |
f2cb1360 | 2351 | |
cd1cb335 VS |
2352 | if (WARN_ON(cpumask_empty(cpu_map))) |
2353 | goto error; | |
2354 | ||
f2cb1360 IM |
2355 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
2356 | if (alloc_state != sa_rootdomain) | |
2357 | goto error; | |
2358 | ||
2359 | /* Set up domains for CPUs specified by the cpu_map: */ | |
2360 | for_each_cpu(i, cpu_map) { | |
2361 | struct sched_domain_topology_level *tl; | |
2362 | ||
2363 | sd = NULL; | |
2364 | for_each_sd_topology(tl) { | |
05484e09 | 2365 | |
ccf74128 VS |
2366 | if (WARN_ON(!topology_span_sane(tl, cpu_map, i))) |
2367 | goto error; | |
2368 | ||
c744dc4a BM |
2369 | sd = build_sched_domain(tl, cpu_map, attr, sd, i); |
2370 | ||
2371 | has_asym |= sd->flags & SD_ASYM_CPUCAPACITY; | |
05484e09 | 2372 | |
f2cb1360 IM |
2373 | if (tl == sched_domain_topology) |
2374 | *per_cpu_ptr(d.sd, i) = sd; | |
af85596c | 2375 | if (tl->flags & SDTL_OVERLAP) |
f2cb1360 IM |
2376 | sd->flags |= SD_OVERLAP; |
2377 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) | |
2378 | break; | |
2379 | } | |
2380 | } | |
2381 | ||
2382 | /* Build the groups for the domains */ | |
2383 | for_each_cpu(i, cpu_map) { | |
2384 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
2385 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
2386 | if (sd->flags & SD_OVERLAP) { | |
2387 | if (build_overlap_sched_groups(sd, i)) | |
2388 | goto error; | |
2389 | } else { | |
2390 | if (build_sched_groups(sd, i)) | |
2391 | goto error; | |
2392 | } | |
2393 | } | |
2394 | } | |
2395 | ||
e496132e MG |
2396 | /* |
2397 | * Calculate an allowed NUMA imbalance such that LLCs do not get | |
2398 | * imbalanced. | |
2399 | */ | |
2400 | for_each_cpu(i, cpu_map) { | |
2401 | unsigned int imb = 0; | |
2402 | unsigned int imb_span = 1; | |
2403 | ||
2404 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
2405 | struct sched_domain *child = sd->child; | |
2406 | ||
2407 | if (!(sd->flags & SD_SHARE_PKG_RESOURCES) && child && | |
2408 | (child->flags & SD_SHARE_PKG_RESOURCES)) { | |
7f434dff | 2409 | struct sched_domain __rcu *top_p; |
e496132e MG |
2410 | unsigned int nr_llcs; |
2411 | ||
2412 | /* | |
2413 | * For a single LLC per node, allow an | |
026b98a9 MG |
2414 | * imbalance up to 12.5% of the node. This is |
2415 | * arbitrary cutoff based two factors -- SMT and | |
2416 | * memory channels. For SMT-2, the intent is to | |
2417 | * avoid premature sharing of HT resources but | |
2418 | * SMT-4 or SMT-8 *may* benefit from a different | |
2419 | * cutoff. For memory channels, this is a very | |
2420 | * rough estimate of how many channels may be | |
2421 | * active and is based on recent CPUs with | |
2422 | * many cores. | |
e496132e MG |
2423 | * |
2424 | * For multiple LLCs, allow an imbalance | |
2425 | * until multiple tasks would share an LLC | |
2426 | * on one node while LLCs on another node | |
026b98a9 MG |
2427 | * remain idle. This assumes that there are |
2428 | * enough logical CPUs per LLC to avoid SMT | |
2429 | * factors and that there is a correlation | |
2430 | * between LLCs and memory channels. | |
e496132e MG |
2431 | */ |
2432 | nr_llcs = sd->span_weight / child->span_weight; | |
2433 | if (nr_llcs == 1) | |
026b98a9 | 2434 | imb = sd->span_weight >> 3; |
e496132e MG |
2435 | else |
2436 | imb = nr_llcs; | |
026b98a9 | 2437 | imb = max(1U, imb); |
e496132e MG |
2438 | sd->imb_numa_nr = imb; |
2439 | ||
2440 | /* Set span based on the first NUMA domain. */ | |
7f434dff | 2441 | top_p = sd->parent; |
e496132e | 2442 | while (top_p && !(top_p->flags & SD_NUMA)) { |
7f434dff | 2443 | top_p = top_p->parent; |
e496132e MG |
2444 | } |
2445 | imb_span = top_p ? top_p->span_weight : sd->span_weight; | |
2446 | } else { | |
2447 | int factor = max(1U, (sd->span_weight / imb_span)); | |
2448 | ||
2449 | sd->imb_numa_nr = imb * factor; | |
2450 | } | |
2451 | } | |
2452 | } | |
2453 | ||
f2cb1360 IM |
2454 | /* Calculate CPU capacity for physical packages and nodes */ |
2455 | for (i = nr_cpumask_bits-1; i >= 0; i--) { | |
2456 | if (!cpumask_test_cpu(i, cpu_map)) | |
2457 | continue; | |
2458 | ||
2459 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
2460 | claim_allocations(i, sd); | |
2461 | init_sched_groups_capacity(i, sd); | |
2462 | } | |
2463 | } | |
2464 | ||
2465 | /* Attach the domains */ | |
2466 | rcu_read_lock(); | |
2467 | for_each_cpu(i, cpu_map) { | |
2468 | rq = cpu_rq(i); | |
2469 | sd = *per_cpu_ptr(d.sd, i); | |
2470 | ||
2471 | /* Use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing: */ | |
2472 | if (rq->cpu_capacity_orig > READ_ONCE(d.rd->max_cpu_capacity)) | |
2473 | WRITE_ONCE(d.rd->max_cpu_capacity, rq->cpu_capacity_orig); | |
2474 | ||
2475 | cpu_attach_domain(sd, d.rd, i); | |
2476 | } | |
2477 | rcu_read_unlock(); | |
2478 | ||
df054e84 | 2479 | if (has_asym) |
e284df70 | 2480 | static_branch_inc_cpuslocked(&sched_asym_cpucapacity); |
df054e84 | 2481 | |
9406415f | 2482 | if (rq && sched_debug_verbose) { |
bf5015a5 | 2483 | pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", |
f2cb1360 IM |
2484 | cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity); |
2485 | } | |
2486 | ||
2487 | ret = 0; | |
2488 | error: | |
2489 | __free_domain_allocs(&d, alloc_state, cpu_map); | |
97fb7a0a | 2490 | |
f2cb1360 IM |
2491 | return ret; |
2492 | } | |
2493 | ||
2494 | /* Current sched domains: */ | |
2495 | static cpumask_var_t *doms_cur; | |
2496 | ||
2497 | /* Number of sched domains in 'doms_cur': */ | |
2498 | static int ndoms_cur; | |
2499 | ||
3b03706f | 2500 | /* Attributes of custom domains in 'doms_cur' */ |
f2cb1360 IM |
2501 | static struct sched_domain_attr *dattr_cur; |
2502 | ||
2503 | /* | |
2504 | * Special case: If a kmalloc() of a doms_cur partition (array of | |
2505 | * cpumask) fails, then fallback to a single sched domain, | |
2506 | * as determined by the single cpumask fallback_doms. | |
2507 | */ | |
8d5dc512 | 2508 | static cpumask_var_t fallback_doms; |
f2cb1360 IM |
2509 | |
2510 | /* | |
2511 | * arch_update_cpu_topology lets virtualized architectures update the | |
2512 | * CPU core maps. It is supposed to return 1 if the topology changed | |
2513 | * or 0 if it stayed the same. | |
2514 | */ | |
2515 | int __weak arch_update_cpu_topology(void) | |
2516 | { | |
2517 | return 0; | |
2518 | } | |
2519 | ||
2520 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) | |
2521 | { | |
2522 | int i; | |
2523 | cpumask_var_t *doms; | |
2524 | ||
6da2ec56 | 2525 | doms = kmalloc_array(ndoms, sizeof(*doms), GFP_KERNEL); |
f2cb1360 IM |
2526 | if (!doms) |
2527 | return NULL; | |
2528 | for (i = 0; i < ndoms; i++) { | |
2529 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
2530 | free_sched_domains(doms, i); | |
2531 | return NULL; | |
2532 | } | |
2533 | } | |
2534 | return doms; | |
2535 | } | |
2536 | ||
2537 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
2538 | { | |
2539 | unsigned int i; | |
2540 | for (i = 0; i < ndoms; i++) | |
2541 | free_cpumask_var(doms[i]); | |
2542 | kfree(doms); | |
2543 | } | |
2544 | ||
2545 | /* | |
cb0c0414 JL |
2546 | * Set up scheduler domains and groups. For now this just excludes isolated |
2547 | * CPUs, but could be used to exclude other special cases in the future. | |
f2cb1360 | 2548 | */ |
ef90cf22 | 2549 | int __init sched_init_domains(const struct cpumask *cpu_map) |
f2cb1360 IM |
2550 | { |
2551 | int err; | |
2552 | ||
8d5dc512 | 2553 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_KERNEL); |
1676330e | 2554 | zalloc_cpumask_var(&sched_domains_tmpmask2, GFP_KERNEL); |
8d5dc512 PZ |
2555 | zalloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
2556 | ||
f2cb1360 | 2557 | arch_update_cpu_topology(); |
c744dc4a | 2558 | asym_cpu_capacity_scan(); |
f2cb1360 IM |
2559 | ndoms_cur = 1; |
2560 | doms_cur = alloc_sched_domains(ndoms_cur); | |
2561 | if (!doms_cur) | |
2562 | doms_cur = &fallback_doms; | |
04d4e665 | 2563 | cpumask_and(doms_cur[0], cpu_map, housekeeping_cpumask(HK_TYPE_DOMAIN)); |
f2cb1360 | 2564 | err = build_sched_domains(doms_cur[0], NULL); |
f2cb1360 IM |
2565 | |
2566 | return err; | |
2567 | } | |
2568 | ||
2569 | /* | |
2570 | * Detach sched domains from a group of CPUs specified in cpu_map | |
2571 | * These CPUs will now be attached to the NULL domain | |
2572 | */ | |
2573 | static void detach_destroy_domains(const struct cpumask *cpu_map) | |
2574 | { | |
e284df70 | 2575 | unsigned int cpu = cpumask_any(cpu_map); |
f2cb1360 IM |
2576 | int i; |
2577 | ||
e284df70 VS |
2578 | if (rcu_access_pointer(per_cpu(sd_asym_cpucapacity, cpu))) |
2579 | static_branch_dec_cpuslocked(&sched_asym_cpucapacity); | |
2580 | ||
f2cb1360 IM |
2581 | rcu_read_lock(); |
2582 | for_each_cpu(i, cpu_map) | |
2583 | cpu_attach_domain(NULL, &def_root_domain, i); | |
2584 | rcu_read_unlock(); | |
2585 | } | |
2586 | ||
2587 | /* handle null as "default" */ | |
2588 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
2589 | struct sched_domain_attr *new, int idx_new) | |
2590 | { | |
2591 | struct sched_domain_attr tmp; | |
2592 | ||
2593 | /* Fast path: */ | |
2594 | if (!new && !cur) | |
2595 | return 1; | |
2596 | ||
2597 | tmp = SD_ATTR_INIT; | |
97fb7a0a | 2598 | |
f2cb1360 IM |
2599 | return !memcmp(cur ? (cur + idx_cur) : &tmp, |
2600 | new ? (new + idx_new) : &tmp, | |
2601 | sizeof(struct sched_domain_attr)); | |
2602 | } | |
2603 | ||
2604 | /* | |
2605 | * Partition sched domains as specified by the 'ndoms_new' | |
2606 | * cpumasks in the array doms_new[] of cpumasks. This compares | |
2607 | * doms_new[] to the current sched domain partitioning, doms_cur[]. | |
2608 | * It destroys each deleted domain and builds each new domain. | |
2609 | * | |
2610 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. | |
2611 | * The masks don't intersect (don't overlap.) We should setup one | |
2612 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
2613 | * not be load balanced. If the same cpumask appears both in the | |
2614 | * current 'doms_cur' domains and in the new 'doms_new', we can leave | |
2615 | * it as it is. | |
2616 | * | |
2617 | * The passed in 'doms_new' should be allocated using | |
2618 | * alloc_sched_domains. This routine takes ownership of it and will | |
2619 | * free_sched_domains it when done with it. If the caller failed the | |
2620 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
2621 | * and partition_sched_domains() will fallback to the single partition | |
2622 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
2623 | * | |
2624 | * If doms_new == NULL it will be replaced with cpu_online_mask. | |
2625 | * ndoms_new == 0 is a special case for destroying existing domains, | |
2626 | * and it will not create the default domain. | |
2627 | * | |
c22645f4 | 2628 | * Call with hotplug lock and sched_domains_mutex held |
f2cb1360 | 2629 | */ |
c22645f4 MP |
2630 | void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], |
2631 | struct sched_domain_attr *dattr_new) | |
f2cb1360 | 2632 | { |
1f74de87 | 2633 | bool __maybe_unused has_eas = false; |
f2cb1360 IM |
2634 | int i, j, n; |
2635 | int new_topology; | |
2636 | ||
c22645f4 | 2637 | lockdep_assert_held(&sched_domains_mutex); |
f2cb1360 | 2638 | |
f2cb1360 IM |
2639 | /* Let the architecture update CPU core mappings: */ |
2640 | new_topology = arch_update_cpu_topology(); | |
c744dc4a BM |
2641 | /* Trigger rebuilding CPU capacity asymmetry data */ |
2642 | if (new_topology) | |
2643 | asym_cpu_capacity_scan(); | |
f2cb1360 | 2644 | |
09e0dd8e PZ |
2645 | if (!doms_new) { |
2646 | WARN_ON_ONCE(dattr_new); | |
2647 | n = 0; | |
2648 | doms_new = alloc_sched_domains(1); | |
2649 | if (doms_new) { | |
2650 | n = 1; | |
edb93821 | 2651 | cpumask_and(doms_new[0], cpu_active_mask, |
04d4e665 | 2652 | housekeeping_cpumask(HK_TYPE_DOMAIN)); |
09e0dd8e PZ |
2653 | } |
2654 | } else { | |
2655 | n = ndoms_new; | |
2656 | } | |
f2cb1360 IM |
2657 | |
2658 | /* Destroy deleted domains: */ | |
2659 | for (i = 0; i < ndoms_cur; i++) { | |
2660 | for (j = 0; j < n && !new_topology; j++) { | |
6aa140fa | 2661 | if (cpumask_equal(doms_cur[i], doms_new[j]) && |
f9a25f77 MP |
2662 | dattrs_equal(dattr_cur, i, dattr_new, j)) { |
2663 | struct root_domain *rd; | |
2664 | ||
2665 | /* | |
2666 | * This domain won't be destroyed and as such | |
2667 | * its dl_bw->total_bw needs to be cleared. It | |
2668 | * will be recomputed in function | |
2669 | * update_tasks_root_domain(). | |
2670 | */ | |
2671 | rd = cpu_rq(cpumask_any(doms_cur[i]))->rd; | |
2672 | dl_clear_root_domain(rd); | |
f2cb1360 | 2673 | goto match1; |
f9a25f77 | 2674 | } |
f2cb1360 IM |
2675 | } |
2676 | /* No match - a current sched domain not in new doms_new[] */ | |
2677 | detach_destroy_domains(doms_cur[i]); | |
2678 | match1: | |
2679 | ; | |
2680 | } | |
2681 | ||
2682 | n = ndoms_cur; | |
09e0dd8e | 2683 | if (!doms_new) { |
f2cb1360 IM |
2684 | n = 0; |
2685 | doms_new = &fallback_doms; | |
edb93821 | 2686 | cpumask_and(doms_new[0], cpu_active_mask, |
04d4e665 | 2687 | housekeeping_cpumask(HK_TYPE_DOMAIN)); |
f2cb1360 IM |
2688 | } |
2689 | ||
2690 | /* Build new domains: */ | |
2691 | for (i = 0; i < ndoms_new; i++) { | |
2692 | for (j = 0; j < n && !new_topology; j++) { | |
6aa140fa QP |
2693 | if (cpumask_equal(doms_new[i], doms_cur[j]) && |
2694 | dattrs_equal(dattr_new, i, dattr_cur, j)) | |
f2cb1360 IM |
2695 | goto match2; |
2696 | } | |
2697 | /* No match - add a new doms_new */ | |
2698 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); | |
2699 | match2: | |
2700 | ; | |
2701 | } | |
2702 | ||
531b5c9f | 2703 | #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) |
6aa140fa QP |
2704 | /* Build perf. domains: */ |
2705 | for (i = 0; i < ndoms_new; i++) { | |
531b5c9f | 2706 | for (j = 0; j < n && !sched_energy_update; j++) { |
6aa140fa | 2707 | if (cpumask_equal(doms_new[i], doms_cur[j]) && |
1f74de87 QP |
2708 | cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) { |
2709 | has_eas = true; | |
6aa140fa | 2710 | goto match3; |
1f74de87 | 2711 | } |
6aa140fa QP |
2712 | } |
2713 | /* No match - add perf. domains for a new rd */ | |
1f74de87 | 2714 | has_eas |= build_perf_domains(doms_new[i]); |
6aa140fa QP |
2715 | match3: |
2716 | ; | |
2717 | } | |
1f74de87 | 2718 | sched_energy_set(has_eas); |
6aa140fa QP |
2719 | #endif |
2720 | ||
f2cb1360 IM |
2721 | /* Remember the new sched domains: */ |
2722 | if (doms_cur != &fallback_doms) | |
2723 | free_sched_domains(doms_cur, ndoms_cur); | |
2724 | ||
2725 | kfree(dattr_cur); | |
2726 | doms_cur = doms_new; | |
2727 | dattr_cur = dattr_new; | |
2728 | ndoms_cur = ndoms_new; | |
2729 | ||
3b87f136 | 2730 | update_sched_domain_debugfs(); |
c22645f4 | 2731 | } |
f2cb1360 | 2732 | |
c22645f4 MP |
2733 | /* |
2734 | * Call with hotplug lock held | |
2735 | */ | |
2736 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], | |
2737 | struct sched_domain_attr *dattr_new) | |
2738 | { | |
2739 | mutex_lock(&sched_domains_mutex); | |
2740 | partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); | |
f2cb1360 IM |
2741 | mutex_unlock(&sched_domains_mutex); |
2742 | } |