diff options
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 56 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 28 |
2 files changed, 39 insertions, 45 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 21e4dcff18f3..c17747236438 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1887,6 +1887,7 @@ context_switch(struct rq *rq, struct task_struct *prev, #endif /* Here we just switch the register state and the stack. */ + rcu_switch(prev, next); switch_to(prev, next, prev); barrier(); @@ -2910,6 +2911,21 @@ asmlinkage void __sched schedule(void) } EXPORT_SYMBOL(schedule); +#ifdef CONFIG_RCU_USER_QS +asmlinkage void __sched schedule_user(void) +{ + /* + * If we come here after a random call to set_need_resched(), + * or we have been woken up remotely but the IPI has not yet arrived, + * we haven't yet exited the RCU idle mode. Do it here manually until + * we find a better solution. + */ + rcu_user_exit(); + schedule(); + rcu_user_enter(); +} +#endif + /** * schedule_preempt_disabled - called with preemption disabled * @@ -3011,6 +3027,7 @@ asmlinkage void __sched preempt_schedule_irq(void) /* Catch callers which need to be fixed */ BUG_ON(ti->preempt_count || !irqs_disabled()); + rcu_user_exit(); do { add_preempt_count(PREEMPT_ACTIVE); local_irq_enable(); @@ -5460,11 +5477,6 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu) * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this * allows us to avoid some pointer chasing select_idle_sibling(). * - * Iterate domains and sched_groups downward, assigning CPUs to be - * select_idle_sibling() hw buddy. Cross-wiring hw makes bouncing - * due to random perturbation self canceling, ie sw buddies pull - * their counterpart to their CPU's hw counterpart. - * * Also keep a unique ID per domain (we use the first cpu number in * the cpumask of the domain), this allows us to quickly tell if * two cpus are in the same cache domain, see cpus_share_cache(). @@ -5478,40 +5490,8 @@ static void update_top_cache_domain(int cpu) int id = cpu; sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); - if (sd) { - struct sched_domain *tmp = sd; - struct sched_group *sg, *prev; - bool right; - - /* - * Traverse to first CPU in group, and count hops - * to cpu from there, switching direction on each - * hop, never ever pointing the last CPU rightward. - */ - do { - id = cpumask_first(sched_domain_span(tmp)); - prev = sg = tmp->groups; - right = 1; - - while (cpumask_first(sched_group_cpus(sg)) != id) - sg = sg->next; - - while (!cpumask_test_cpu(cpu, sched_group_cpus(sg))) { - prev = sg; - sg = sg->next; - right = !right; - } - - /* A CPU went down, never point back to domain start. */ - if (right && cpumask_first(sched_group_cpus(sg->next)) == id) - right = false; - - sg = right ? sg->next : prev; - tmp->idle_buddy = cpumask_first(sched_group_cpus(sg)); - } while ((tmp = tmp->child)); - + if (sd) id = cpumask_first(sched_domain_span(sd)); - } rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); per_cpu(sd_llc_id, cpu) = id; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index de596a2f626c..6b800a14b990 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2637,6 +2637,8 @@ static int select_idle_sibling(struct task_struct *p, int target) int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); struct sched_domain *sd; + struct sched_group *sg; + int i; /* * If the task is going to be woken-up on this cpu and if it is @@ -2653,17 +2655,29 @@ static int select_idle_sibling(struct task_struct *p, int target) return prev_cpu; /* - * Otherwise, check assigned siblings to find an elegible idle cpu. + * Otherwise, iterate the domains and find an elegible idle cpu. */ sd = rcu_dereference(per_cpu(sd_llc, target)); - for_each_lower_domain(sd) { - if (!cpumask_test_cpu(sd->idle_buddy, tsk_cpus_allowed(p))) - continue; - if (idle_cpu(sd->idle_buddy)) - return sd->idle_buddy; - } + sg = sd->groups; + do { + if (!cpumask_intersects(sched_group_cpus(sg), + tsk_cpus_allowed(p))) + goto next; + for_each_cpu(i, sched_group_cpus(sg)) { + if (!idle_cpu(i)) + goto next; + } + + target = cpumask_first_and(sched_group_cpus(sg), + tsk_cpus_allowed(p)); + goto done; +next: + sg = sg->next; + } while (sg != sd->groups); + } +done: return target; } |
