Messages in this thread Patch in this message | | | From | Ricardo Neri <> | Subject | [PATCH v3 4/6] sched/fair: Carve out logic to mark a group for asymmetric packing | Date | Thu, 13 May 2021 08:49:07 -0700 |
| |
Currently when balancing load, a candidate busiest group is marked for asymmetric packing if, among other factors, dst_cpu has higher priority than the preferred CPU of the candidate busiest group. However, other factors influence the decision, such as the state of the SMT siblings of dst_cpu, if any.
Thus, create a separate function, sched_asym(), in which logic for such decisions can be implemented. A subsequent changeset will introduce logic to deal with SMT.
Cc: Aubrey Li <aubrey.li@intel.com> Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Len Brown <len.brown@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Quentin Perret <qperret@google.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- Changes since v2: * Introduced this patch.
Changes since v1: * N/A --- kernel/sched/fair.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c8c04e9d0d3b..c8b66a5d593e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8447,6 +8447,20 @@ 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) +{ + /* + * Because sd->groups starts with the local group, anything that isn't + * the local group will have access to the local state. + */ + if (group == sds->local) + return false; + + 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. @@ -8507,18 +8521,17 @@ 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 */ -- 2.17.1
| |