Messages in this thread Patch in this message | | | From | Yuyang Du <> | Subject | [RFC PATCH 16/16 v3] Intercept periodic load balancing | Date | Fri, 30 May 2014 14:36:12 +0800 |
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We intercept load balancing to contain the load and load balancing in the consolidated CPUs according to our consolidating mechanism.
In periodic load balancing, we do two things:
1) Skip pulling task to the non-consolidated CPUs.
2) In addition, for consolidated Idle CPU, we aggressively pull tasks from non-consolidated CPUs.
Signed-off-by: Yuyang Du <yuyang.du@intel.com> --- kernel/sched/fair.c | 51 ++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 44 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1b8dd45..d22ac87 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7260,17 +7260,54 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle, struc static void run_rebalance_domains(struct softirq_action *h) { struct rq *this_rq = this_rq(); + int this_cpu = cpu_of(this_rq); + struct sched_domain *sd; enum cpu_idle_type idle = this_rq->idle_balance ? CPU_IDLE : CPU_NOT_IDLE; - rebalance_domains(this_rq, idle); + rcu_read_lock(); + sd = top_flag_domain(this_cpu, SD_WORKLOAD_CONSOLIDATION); + if (sd) { + struct cpumask *nonshielded_cpus = __get_cpu_var(load_balance_mask); - /* - * If this cpu has a pending nohz_balance_kick, then do the - * balancing on behalf of the other idle cpus whose ticks are - * stopped. - */ - nohz_idle_balance(this_rq, idle); + /* + * if we encounter shielded cpus here, don't do balance on them + */ + cpumask_copy(nonshielded_cpus, cpu_active_mask); + + wc_nonshielded_mask(this_cpu, sd, nonshielded_cpus); + + /* + * aggressively unload the shielded cpus to unshielded cpus + */ + wc_unload(nonshielded_cpus, sd); + rcu_read_unlock(); + + if (cpumask_test_cpu(this_cpu, nonshielded_cpus)) { + struct cpumask *idle_cpus = __get_cpu_var(local_cpu_mask); + cpumask_and(idle_cpus, nonshielded_cpus, nohz.idle_cpus_mask); + + rebalance_domains(this_rq, idle); + + /* + * If this cpu has a pending nohz_balance_kick, then do the + * balancing on behalf of the other idle cpus whose ticks are + * stopped. + */ + nohz_idle_balance(this_rq, idle, idle_cpus); + } + } + else { + rcu_read_unlock(); + rebalance_domains(this_rq, idle); + + /* + * If this cpu has a pending nohz_balance_kick, then do the + * balancing on behalf of the other idle cpus whose ticks are + * stopped. + */ + nohz_idle_balance(this_rq, idle, nohz.idle_cpus_mask); + } } /* -- 1.7.9.5
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