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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-09-10 07:36:25 -0400
committerIngo Molnar <mingo@elte.hu>2009-09-15 10:01:04 -0400
commitaaee1203ca52b9db799433c33c9bffc33cdf8909 (patch)
tree27da699a8034090f8be9e24d1b7cedb8f6cdf804 /kernel/sched.c
parentf5f08f39ee4c5fd0a757d25d9e04d696676b3df7 (diff)
sched: Move sched_balance_self() into sched_fair.c
Move the sched_balance_self() code into sched_fair.c This facilitates the merger of sched_balance_self() and sched_fair::select_task_rq(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c146
1 files changed, 0 insertions, 146 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index b56d1505d058..60400a22401f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2269,152 +2269,6 @@ void kick_process(struct task_struct *p)
2269 preempt_enable(); 2269 preempt_enable();
2270} 2270}
2271EXPORT_SYMBOL_GPL(kick_process); 2271EXPORT_SYMBOL_GPL(kick_process);
2272
2273/*
2274 * find_idlest_group finds and returns the least busy CPU group within the
2275 * domain.
2276 */
2277static struct sched_group *
2278find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
2279{
2280 struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups;
2281 unsigned long min_load = ULONG_MAX, this_load = 0;
2282 int load_idx = sd->forkexec_idx;
2283 int imbalance = 100 + (sd->imbalance_pct-100)/2;
2284
2285 do {
2286 unsigned long load, avg_load;
2287 int local_group;
2288 int i;
2289
2290 /* Skip over this group if it has no CPUs allowed */
2291 if (!cpumask_intersects(sched_group_cpus(group),
2292 &p->cpus_allowed))
2293 continue;
2294
2295 local_group = cpumask_test_cpu(this_cpu,
2296 sched_group_cpus(group));
2297
2298 /* Tally up the load of all CPUs in the group */
2299 avg_load = 0;
2300
2301 for_each_cpu(i, sched_group_cpus(group)) {
2302 /* Bias balancing toward cpus of our domain */
2303 if (local_group)
2304 load = source_load(i, load_idx);
2305 else
2306 load = target_load(i, load_idx);
2307
2308 avg_load += load;
2309 }
2310
2311 /* Adjust by relative CPU power of the group */
2312 avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power;
2313
2314 if (local_group) {
2315 this_load = avg_load;
2316 this = group;
2317 } else if (avg_load < min_load) {
2318 min_load = avg_load;
2319 idlest = group;
2320 }
2321 } while (group = group->next, group != sd->groups);
2322
2323 if (!idlest || 100*this_load < imbalance*min_load)
2324 return NULL;
2325 return idlest;
2326}
2327
2328/*
2329 * find_idlest_cpu - find the idlest cpu among the cpus in group.
2330 */
2331static int
2332find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
2333{
2334 unsigned long load, min_load = ULONG_MAX;
2335 int idlest = -1;
2336 int i;
2337
2338 /* Traverse only the allowed CPUs */
2339 for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) {
2340 load = weighted_cpuload(i);
2341
2342 if (load < min_load || (load == min_load && i == this_cpu)) {
2343 min_load = load;
2344 idlest = i;
2345 }
2346 }
2347
2348 return idlest;
2349}
2350
2351/*
2352 * sched_balance_self: balance the current task (running on cpu) in domains
2353 * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
2354 * SD_BALANCE_EXEC.
2355 *
2356 * Balance, ie. select the least loaded group.
2357 *
2358 * Returns the target CPU number, or the same CPU if no balancing is needed.
2359 *
2360 * preempt must be disabled.
2361 */
2362static int sched_balance_self(int cpu, int flag)
2363{
2364 struct task_struct *t = current;
2365 struct sched_domain *tmp, *sd = NULL;
2366
2367 for_each_domain(cpu, tmp) {
2368 /*
2369 * If power savings logic is enabled for a domain, stop there.
2370 */
2371 if (tmp->flags & SD_POWERSAVINGS_BALANCE)
2372 break;
2373 if (tmp->flags & flag)
2374 sd = tmp;
2375 }
2376
2377 if (sd)
2378 update_shares(sd);
2379
2380 while (sd) {
2381 struct sched_group *group;
2382 int new_cpu, weight;
2383
2384 if (!(sd->flags & flag)) {
2385 sd = sd->child;
2386 continue;
2387 }
2388
2389 group = find_idlest_group(sd, t, cpu);
2390 if (!group) {
2391 sd = sd->child;
2392 continue;
2393 }
2394
2395 new_cpu = find_idlest_cpu(group, t, cpu);
2396 if (new_cpu == -1 || new_cpu == cpu) {
2397 /* Now try balancing at a lower domain level of cpu */
2398 sd = sd->child;
2399 continue;
2400 }
2401
2402 /* Now try balancing at a lower domain level of new_cpu */
2403 cpu = new_cpu;
2404 weight = cpumask_weight(sched_domain_span(sd));
2405 sd = NULL;
2406 for_each_domain(cpu, tmp) {
2407 if (weight <= cpumask_weight(sched_domain_span(tmp)))
2408 break;
2409 if (tmp->flags & flag)
2410 sd = tmp;
2411 }
2412 /* while loop will break here if sd == NULL */
2413 }
2414
2415 return cpu;
2416}
2417
2418#endif /* CONFIG_SMP */ 2272#endif /* CONFIG_SMP */
2419 2273
2420/** 2274/**