diff options
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 46d64e4ccfde..e7dd0ec169be 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3030,7 +3030,14 @@ static int idle_balance(struct rq *this_rq); #else /* CONFIG_SMP */ -static inline void update_load_avg(struct sched_entity *se, int update_tg) {} +static inline void update_load_avg(struct sched_entity *se, int not_used) +{ + struct cfs_rq *cfs_rq = cfs_rq_of(se); + struct rq *rq = rq_of(cfs_rq); + + cpufreq_trigger_update(rq_clock(rq)); +} + static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} static inline void @@ -5071,7 +5078,19 @@ static int select_idle_sibling(struct task_struct *p, int target) return i; /* - * Otherwise, iterate the domains and find an elegible idle cpu. + * Otherwise, iterate the domains and find an eligible idle cpu. + * + * A completely idle sched group at higher domains is more + * desirable than an idle group at a lower level, because lower + * domains have smaller groups and usually share hardware + * resources which causes tasks to contend on them, e.g. x86 + * hyperthread siblings in the lowest domain (SMT) can contend + * on the shared cpu pipeline. + * + * However, while we prefer idle groups at higher domains + * finding an idle cpu at the lowest domain is still better than + * returning 'target', which we've already established, isn't + * idle. */ sd = rcu_dereference(per_cpu(sd_llc, target)); for_each_lower_domain(sd) { @@ -5081,11 +5100,16 @@ static int select_idle_sibling(struct task_struct *p, int target) tsk_cpus_allowed(p))) goto next; + /* Ensure the entire group is idle */ for_each_cpu(i, sched_group_cpus(sg)) { if (i == target || !idle_cpu(i)) goto next; } + /* + * It doesn't matter which cpu we pick, the + * whole group is idle. + */ target = cpumask_first_and(sched_group_cpus(sg), tsk_cpus_allowed(p)); goto done; |
