From: Valentin Schneider <[email protected]> The name "overload" is not very explicit, especially since it doesn't use any concept of "load" coming from load-tracking signals. For now it simply tracks if any of the CPUs in root_domain has more than one runnable task, and is then used to decide whether idle balance should be performed.
As such, this commit changes that flag's name to 'should_idle_balance', which makes its role more explicit. cc: Ingo Molnar <[email protected]> cc: Peter Zijlstra <[email protected]> Suggested-by: Patrick Bellasi <[email protected]> Signed-off-by: Valentin Schneider <[email protected]> Signed-off-by: Morten Rasmussen <[email protected]> --- kernel/sched/fair.c | 18 +++++++++--------- kernel/sched/sched.h | 12 ++++++++---- 2 files changed, 17 insertions(+), 13 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1439b784b1f0..2d2302b7b584 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7830,12 +7830,12 @@ group_type group_classify(struct sched_group *group, * @load_idx: Load index of sched_domain of this_cpu for load calc. * @local_group: Does group contain this_cpu. * @sgs: variable to hold the statistics for this group. - * @overload: Indicate more than one runnable task for any CPU. + * @should_idle_balance: Indicate groups could need idle balance. */ static inline void update_sg_lb_stats(struct lb_env *env, struct sched_group *group, int load_idx, int local_group, struct sg_lb_stats *sgs, - bool *overload) + bool *should_idle_balance) { unsigned long load; int i, nr_running; @@ -7857,7 +7857,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, nr_running = rq->nr_running; if (nr_running > 1) - *overload = true; + *should_idle_balance = true; #ifdef CONFIG_NUMA_BALANCING sgs->nr_numa_running += rq->nr_numa_running; @@ -8016,7 +8016,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd struct sg_lb_stats *local = &sds->local_stat; struct sg_lb_stats tmp_sgs; int load_idx, prefer_sibling = 0; - bool overload = false; + bool should_idle_balance = false; if (child && child->flags & SD_PREFER_SIBLING) prefer_sibling = 1; @@ -8038,7 +8038,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd } update_sg_lb_stats(env, sg, load_idx, local_group, sgs, - &overload); + &should_idle_balance); if (local_group) goto next_group; @@ -8078,9 +8078,9 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd env->fbq_type = fbq_classify_group(&sds->busiest_stat); if (!env->sd->parent) { - /* update overload indicator if we are at root domain */ - if (env->dst_rq->rd->overload != overload) - env->dst_rq->rd->overload = overload; + /* update idle_balance indicator if we are at root domain */ + if (env->dst_rq->rd->should_idle_balance != should_idle_balance) + env->dst_rq->rd->should_idle_balance = should_idle_balance; } } @@ -8878,7 +8878,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) rq_unpin_lock(this_rq, rf); if (this_rq->avg_idle < sysctl_sched_migration_cost || - !this_rq->rd->overload) { + !this_rq->rd->should_idle_balance) { rcu_read_lock(); sd = rcu_dereference_check_sched_domain(this_rq->sd); if (sd) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 7d324b706e67..4215438667e5 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -650,8 +650,12 @@ struct root_domain { cpumask_var_t span; cpumask_var_t online; - /* Indicate more than one runnable task for any CPU */ - bool overload; + /* + * Indicate whether the idle balance can be used to solve + * imbalance within the root domain. + * e.g. There is more than one runnable task for any CPU + */ + bool should_idle_balance; /* * The bit corresponding to a CPU gets set here if such CPU has more @@ -1610,8 +1614,8 @@ static inline void add_nr_running(struct rq *rq, unsigned count) if (prev_nr < 2 && rq->nr_running >= 2) { #ifdef CONFIG_SMP - if (!rq->rd->overload) - rq->rd->overload = true; + if (!rq->rd->should_idle_balance) + rq->rd->should_idle_balance = true; #endif } -- 2.7.4
