sched/fair: Carve out logic to mark a group for asymmetric packing

Create a separate function, sched_asym(). A subsequent changeset will
introduce logic to deal with SMT in conjunction with asmymmetric
packing. Such logic will need the statistics of the scheduling
group provided as argument. Update them before calling sched_asym().

Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Len Brown <len.brown@intel.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210911011819.12184-6-ricardo.neri-calderon@linux.intel.com

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2e8ef337c7d47b0c7aa0a8252f186534ac990538..1c8b5fa58c232d89aa96c2f11401a9a399ad2fa3 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8571,6 +8571,13 @@ group_type group_classify(unsigned int imbalance_pct,
        return group_has_spare;
 }
 
+static inline bool
+sched_asym(struct lb_env *env, struct sd_lb_stats *sds,  struct sg_lb_stats *sgs,
+          struct sched_group *group)
+{
+       return sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu);
+}
+
 /**
  * update_sg_lb_stats - Update sched_group's statistics for load balancing.
  * @env: The load balancing environment.
@@ -8631,18 +8638,17 @@ static inline void update_sg_lb_stats(struct lb_env *env,
                }
        }
 
+       sgs->group_capacity = group->sgc->capacity;
+
+       sgs->group_weight = group->group_weight;
+
        /* Check if dst CPU is idle and preferred to this group */
        if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
-           env->idle != CPU_NOT_IDLE &&
-           sgs->sum_h_nr_running &&
-           sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu)) {
+           env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
+           sched_asym(env, sds, sgs, group)) {
                sgs->group_asym_packing = 1;
        }
 
-       sgs->group_capacity = group->sgc->capacity;
-
-       sgs->group_weight = group->group_weight;
-
        sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs);
 
        /* Computing avg_load makes sense only when group is overloaded */