From 630246a06ae2a7a12d1fce85f1e5681032982791 Mon Sep 17 00:00:00 2001 From: Quentin Perret Date: Mon, 3 Dec 2018 09:56:24 +0000 Subject: [PATCH] sched/fair: Clean-up update_sg_lb_stats parameters In preparation for the introduction of a new root domain flag which can be set during load balance (the 'overutilized' flag), clean-up the set of parameters passed to update_sg_lb_stats(). More specifically, the 'local_group' and 'local_idx' parameters can be removed since they can easily be reconstructed from within the function. While at it, transform the 'overload' parameter into a flag stored in the 'sg_status' parameter hence facilitating the definition of new flags when needed. Suggested-by: Peter Zijlstra Suggested-by: Valentin Schneider Signed-off-by: Quentin Perret Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Thomas Gleixner Cc: adharmap@codeaurora.org Cc: chris.redpath@arm.com Cc: currojerez@riseup.net Cc: dietmar.eggemann@arm.com Cc: edubezval@gmail.com Cc: gregkh@linuxfoundation.org Cc: javi.merino@kernel.org Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: pkondeti@codeaurora.org Cc: rjw@rjwysocki.net Cc: skannan@codeaurora.org Cc: smuckle@google.com Cc: srinivas.pandruvada@linux.intel.com Cc: thara.gopinath@linaro.org Cc: tkjos@google.com Cc: vincent.guittot@linaro.org Cc: viresh.kumar@linaro.org Link: https://lkml.kernel.org/r/20181203095628.11858-12-quentin.perret@arm.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 27 +++++++++++---------------- kernel/sched/sched.h | 3 +++ 2 files changed, 14 insertions(+), 16 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a31a6d325901..e04f29098ec7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7905,16 +7905,16 @@ static bool update_nohz_stats(struct rq *rq, bool force) * update_sg_lb_stats - Update sched_group's statistics for load balancing. * @env: The load balancing environment. * @group: sched_group whose statistics are to be updated. - * @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 pullable load (e.g. >1 runnable task). + * @sg_status: Holds flag indicating the status of the sched_group */ 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) + struct sched_group *group, + struct sg_lb_stats *sgs, + int *sg_status) { + int local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group)); + int load_idx = get_sd_load_idx(env->sd, env->idle); unsigned long load; int i, nr_running; @@ -7938,7 +7938,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, nr_running = rq->nr_running; if (nr_running > 1) - *overload = true; + *sg_status |= SG_OVERLOAD; #ifdef CONFIG_NUMA_BALANCING sgs->nr_numa_running += rq->nr_numa_running; @@ -7954,7 +7954,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, if (env->sd->flags & SD_ASYM_CPUCAPACITY && sgs->group_misfit_task_load < rq->misfit_task_load) { sgs->group_misfit_task_load = rq->misfit_task_load; - *overload = 1; + *sg_status |= SG_OVERLOAD; } } @@ -8099,17 +8099,14 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd struct sched_group *sg = env->sd->groups; struct sg_lb_stats *local = &sds->local_stat; struct sg_lb_stats tmp_sgs; - int load_idx; - bool overload = false; bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING; + int sg_status = 0; #ifdef CONFIG_NO_HZ_COMMON if (env->idle == CPU_NEWLY_IDLE && READ_ONCE(nohz.has_blocked)) env->flags |= LBF_NOHZ_STATS; #endif - load_idx = get_sd_load_idx(env->sd, env->idle); - do { struct sg_lb_stats *sgs = &tmp_sgs; int local_group; @@ -8124,8 +8121,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd update_group_capacity(env->sd, env->dst_cpu); } - update_sg_lb_stats(env, sg, load_idx, local_group, sgs, - &overload); + update_sg_lb_stats(env, sg, sgs, &sg_status); if (local_group) goto next_group; @@ -8175,8 +8171,7 @@ next_group: if (!env->sd->parent) { /* update overload indicator if we are at root domain */ - if (READ_ONCE(env->dst_rq->rd->overload) != overload) - WRITE_ONCE(env->dst_rq->rd->overload, overload); + WRITE_ONCE(env->dst_rq->rd->overload, sg_status & SG_OVERLOAD); } } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2b3cf356e958..d4d984846924 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -716,6 +716,9 @@ struct perf_domain { struct rcu_head rcu; }; +/* Scheduling group status flags */ +#define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ + /* * We add the notion of a root-domain which will be used to define per-domain * variables. Each exclusive cpuset essentially defines an island domain by