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sched/fair: Move rebalance_domains()

This pure code movement results in two #ifdef CONFIG_NO_HZ_COMMON
sections landing next to each other.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Peter Zijlstra 2018-02-20 10:58:39 +01:00 committed by Ingo Molnar
parent 63928384fa
commit af3fe03c56
1 changed files with 118 additions and 118 deletions

View File

@ -9121,6 +9121,124 @@ out_unlock:
return 0;
}
static DEFINE_SPINLOCK(balancing);
/*
* Scale the max load_balance interval with the number of CPUs in the system.
* This trades load-balance latency on larger machines for less cross talk.
*/
void update_max_interval(void)
{
max_load_balance_interval = HZ*num_online_cpus()/10;
}
/*
* It checks each scheduling domain to see if it is due to be balanced,
* and initiates a balancing operation if so.
*
* Balancing parameters are set up in init_sched_domains.
*/
static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
{
int continue_balancing = 1;
int cpu = rq->cpu;
unsigned long interval;
struct sched_domain *sd;
/* Earliest time when we have to do rebalance again */
unsigned long next_balance = jiffies + 60*HZ;
int update_next_balance = 0;
int need_serialize, need_decay = 0;
u64 max_cost = 0;
rcu_read_lock();
for_each_domain(cpu, sd) {
/*
* Decay the newidle max times here because this is a regular
* visit to all the domains. Decay ~1% per second.
*/
if (time_after(jiffies, sd->next_decay_max_lb_cost)) {
sd->max_newidle_lb_cost =
(sd->max_newidle_lb_cost * 253) / 256;
sd->next_decay_max_lb_cost = jiffies + HZ;
need_decay = 1;
}
max_cost += sd->max_newidle_lb_cost;
if (!(sd->flags & SD_LOAD_BALANCE))
continue;
/*
* Stop the load balance at this level. There is another
* CPU in our sched group which is doing load balancing more
* actively.
*/
if (!continue_balancing) {
if (need_decay)
continue;
break;
}
interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
need_serialize = sd->flags & SD_SERIALIZE;
if (need_serialize) {
if (!spin_trylock(&balancing))
goto out;
}
if (time_after_eq(jiffies, sd->last_balance + interval)) {
if (load_balance(cpu, rq, sd, idle, &continue_balancing)) {
/*
* The LBF_DST_PINNED logic could have changed
* env->dst_cpu, so we can't know our idle
* state even if we migrated tasks. Update it.
*/
idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
}
sd->last_balance = jiffies;
interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
}
if (need_serialize)
spin_unlock(&balancing);
out:
if (time_after(next_balance, sd->last_balance + interval)) {
next_balance = sd->last_balance + interval;
update_next_balance = 1;
}
}
if (need_decay) {
/*
* Ensure the rq-wide value also decays but keep it at a
* reasonable floor to avoid funnies with rq->avg_idle.
*/
rq->max_idle_balance_cost =
max((u64)sysctl_sched_migration_cost, max_cost);
}
rcu_read_unlock();
/*
* next_balance will be updated only when there is a need.
* When the cpu is attached to null domain for ex, it will not be
* updated.
*/
if (likely(update_next_balance)) {
rq->next_balance = next_balance;
#ifdef CONFIG_NO_HZ_COMMON
/*
* If this CPU has been elected to perform the nohz idle
* balance. Other idle CPUs have already rebalanced with
* nohz_idle_balance() and nohz.next_balance has been
* updated accordingly. This CPU is now running the idle load
* balance for itself and we need to update the
* nohz.next_balance accordingly.
*/
if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance))
nohz.next_balance = rq->next_balance;
#endif
}
}
static inline int on_null_domain(struct rq *rq)
{
return unlikely(!rcu_dereference_sched(rq->sd));
@ -9373,124 +9491,6 @@ out:
static inline void nohz_balancer_kick(struct rq *rq) { }
#endif
static DEFINE_SPINLOCK(balancing);
/*
* Scale the max load_balance interval with the number of CPUs in the system.
* This trades load-balance latency on larger machines for less cross talk.
*/
void update_max_interval(void)
{
max_load_balance_interval = HZ*num_online_cpus()/10;
}
/*
* It checks each scheduling domain to see if it is due to be balanced,
* and initiates a balancing operation if so.
*
* Balancing parameters are set up in init_sched_domains.
*/
static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
{
int continue_balancing = 1;
int cpu = rq->cpu;
unsigned long interval;
struct sched_domain *sd;
/* Earliest time when we have to do rebalance again */
unsigned long next_balance = jiffies + 60*HZ;
int update_next_balance = 0;
int need_serialize, need_decay = 0;
u64 max_cost = 0;
rcu_read_lock();
for_each_domain(cpu, sd) {
/*
* Decay the newidle max times here because this is a regular
* visit to all the domains. Decay ~1% per second.
*/
if (time_after(jiffies, sd->next_decay_max_lb_cost)) {
sd->max_newidle_lb_cost =
(sd->max_newidle_lb_cost * 253) / 256;
sd->next_decay_max_lb_cost = jiffies + HZ;
need_decay = 1;
}
max_cost += sd->max_newidle_lb_cost;
if (!(sd->flags & SD_LOAD_BALANCE))
continue;
/*
* Stop the load balance at this level. There is another
* CPU in our sched group which is doing load balancing more
* actively.
*/
if (!continue_balancing) {
if (need_decay)
continue;
break;
}
interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
need_serialize = sd->flags & SD_SERIALIZE;
if (need_serialize) {
if (!spin_trylock(&balancing))
goto out;
}
if (time_after_eq(jiffies, sd->last_balance + interval)) {
if (load_balance(cpu, rq, sd, idle, &continue_balancing)) {
/*
* The LBF_DST_PINNED logic could have changed
* env->dst_cpu, so we can't know our idle
* state even if we migrated tasks. Update it.
*/
idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
}
sd->last_balance = jiffies;
interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
}
if (need_serialize)
spin_unlock(&balancing);
out:
if (time_after(next_balance, sd->last_balance + interval)) {
next_balance = sd->last_balance + interval;
update_next_balance = 1;
}
}
if (need_decay) {
/*
* Ensure the rq-wide value also decays but keep it at a
* reasonable floor to avoid funnies with rq->avg_idle.
*/
rq->max_idle_balance_cost =
max((u64)sysctl_sched_migration_cost, max_cost);
}
rcu_read_unlock();
/*
* next_balance will be updated only when there is a need.
* When the CPU is attached to null domain for ex, it will not be
* updated.
*/
if (likely(update_next_balance)) {
rq->next_balance = next_balance;
#ifdef CONFIG_NO_HZ_COMMON
/*
* If this CPU has been elected to perform the nohz idle
* balance. Other idle CPUs have already rebalanced with
* nohz_idle_balance() and nohz.next_balance has been
* updated accordingly. This CPU is now running the idle load
* balance for itself and we need to update the
* nohz.next_balance accordingly.
*/
if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance))
nohz.next_balance = rq->next_balance;
#endif
}
}
#ifdef CONFIG_NO_HZ_COMMON
/*
* In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the