From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932340Ab2F1C5I (ORCPT ); Wed, 27 Jun 2012 22:57:08 -0400 Received: from mail-ee0-f74.google.com ([74.125.83.74]:42932 "EHLO mail-ee0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758168Ab2F1C40 (ORCPT ); Wed, 27 Jun 2012 22:56:26 -0400 Subject: [PATCH 16/16] sched: introduce temporary FAIR_GROUP_SCHED dependency for load-tracking To: linux-kernel@vger.kernel.org From: Paul Turner Cc: Venki Pallipadi , Srivatsa Vaddagiri , Vincent Guittot , Peter Zijlstra , Nikunj A Dadhania , Mike Galbraith , Kamalesh Babulal , Ben Segall , Ingo Molnar , "Paul E. McKenney" , Morten Rasmussen , Vaidyanathan Srinivasan Date: Wed, 27 Jun 2012 19:24:15 -0700 Message-ID: <20120628022415.30496.18884.stgit@kitami.mtv.corp.google.com> In-Reply-To: <20120628022413.30496.32798.stgit@kitami.mtv.corp.google.com> References: <20120628022413.30496.32798.stgit@kitami.mtv.corp.google.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- include/linux/sched.h | 8 +++++++- kernel/sched/fair.c | 14 +++++++++++--- kernel/sched/sched.h | 9 ++++++++- 3 files changed, 26 insertions(+), 5 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index a65c097..7c0c72d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1205,7 +1205,13 @@ 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/fair.c b/kernel/sched/fair.c index 3d1aaa8..0b6e2df 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. @@ -3214,6 +3215,12 @@ 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 @@ -3235,7 +3242,7 @@ 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 */ @@ -5927,8 +5934,9 @@ 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 bb76895..d920943 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, tg_usage_contrib; u64 tg_load_contrib;