Commit-ID: f4e26b120b9de84cb627bc7361ba43cfdc51341f Gitweb: http://git.kernel.org/tip/f4e26b120b9de84cb627bc7361ba43cfdc51341f Author: Paul Turner <[email protected]> AuthorDate: Thu, 4 Oct 2012 13:18:32 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 24 Oct 2012 10:27:31 +0200
sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking While per-entity load-tracking is generally useful, beyond computing shares distribution, e.g. runnable based load-balance (in progress), governors, power-management, etc. These facilities are not yet consumers of this data. This may be trivially reverted when the information is required; but avoid paying the overhead for calculations we will not use until then. Signed-off-by: Paul Turner <[email protected]> Reviewed-by: Ben Segall <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/sched.h | 8 +++++++- kernel/sched/core.c | 7 ++++++- kernel/sched/fair.c | 13 +++++++++++-- kernel/sched/sched.h | 9 ++++++++- 4 files changed, 32 insertions(+), 5 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index e483ccb..e1581a0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1168,7 +1168,13 @@ struct sched_entity { /* rq "owned" by this entity/group: */ struct cfs_rq *my_q; #endif -#ifdef CONFIG_SMP +/* + * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be + * removed when useful for applications beyond shares distribution (e.g. + * load-balance). + */ +#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED) + /* Per-entity load-tracking */ struct sched_avg avg; #endif }; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f268600..5dae0d2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1526,7 +1526,12 @@ static void __sched_fork(struct task_struct *p) p->se.vruntime = 0; INIT_LIST_HEAD(&p->se.group_node); -#ifdef CONFIG_SMP +/* + * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be + * removed when useful for applications beyond shares distribution (e.g. + * load-balance). + */ +#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED) p->se.avg.runnable_avg_period = 0; p->se.avg.runnable_avg_sum = 0; #endif diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6ecf455..3e6a353 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -882,7 +882,8 @@ static inline void update_cfs_shares(struct cfs_rq *cfs_rq) } #endif /* CONFIG_FAIR_GROUP_SCHED */ -#ifdef CONFIG_SMP +/* Only depends on SMP, FAIR_GROUP_SCHED may be removed when useful in lb */ +#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED) /* * We choose a half-life close to 1 scheduling period. * Note: The tables below are dependent on this value. @@ -3174,6 +3175,12 @@ unlock: } /* + * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be + * removed when useful for applications beyond shares distribution (e.g. + * load-balance). + */ +#ifdef CONFIG_FAIR_GROUP_SCHED +/* * Called immediately before a task is migrated to a new cpu; task_cpu(p) and * cfs_rq_of(p) references at time of call are still valid and identify the * previous cpu. However, the caller only guarantees p->pi_lock is held; no @@ -3196,6 +3203,7 @@ migrate_task_rq_fair(struct task_struct *p, int next_cpu) atomic64_add(se->avg.load_avg_contrib, &cfs_rq->removed_load); } } +#endif #endif /* CONFIG_SMP */ static unsigned long @@ -5773,8 +5781,9 @@ const struct sched_class fair_sched_class = { #ifdef CONFIG_SMP .select_task_rq = select_task_rq_fair, +#ifdef CONFIG_FAIR_GROUP_SCHED .migrate_task_rq = migrate_task_rq_fair, - +#endif .rq_online = rq_online_fair, .rq_offline = rq_offline_fair, diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0a75a43..5eca173 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -225,6 +225,12 @@ struct cfs_rq { #endif #ifdef CONFIG_SMP +/* + * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be + * removed when useful for applications beyond shares distribution (e.g. + * load-balance). + */ +#ifdef CONFIG_FAIR_GROUP_SCHED /* * CFS Load tracking * Under CFS, load is tracked on a per-entity basis and aggregated up. @@ -234,7 +240,8 @@ struct cfs_rq { u64 runnable_load_avg, blocked_load_avg; atomic64_t decay_counter, removed_load; u64 last_decay; - +#endif /* CONFIG_FAIR_GROUP_SCHED */ +/* These always depend on CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_FAIR_GROUP_SCHED u32 tg_runnable_contrib; u64 tg_load_contrib; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
