From mboxrd@z Thu Jan 1 00:00:00 1970 From: Morten Rasmussen Subject: [RFCv2 PATCH 17/23] sched: Likely idle state statistics placeholder Date: Thu, 3 Jul 2014 17:26:04 +0100 Message-ID: <1404404770-323-18-git-send-email-morten.rasmussen@arm.com> References: <1404404770-323-1-git-send-email-morten.rasmussen@arm.com> Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Return-path: Received: from service87.mimecast.com ([91.220.42.44]:47352 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758267AbaGCQ0y (ORCPT ); Thu, 3 Jul 2014 12:26:54 -0400 In-Reply-To: <1404404770-323-1-git-send-email-morten.rasmussen@arm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, peterz@infradead.org, mingo@kernel.org Cc: rjw@rjwysocki.net, vincent.guittot@linaro.org, daniel.lezcano@linaro.org, preeti@linux.vnet.ibm.com, Dietmar.Eggemann@arm.com, pjt@google.com The scheduler is currently completely unaware of idle-states. To make informed decisions using the sched_group_energy idle_states list it is necessary to know which idle-state a cpu (or group of cpus) is most likely to be in when it is idle. For example when migrating a task that wakes up periodically, the wakeup energy expense depends on the idle-state the destination cpu is most likely to be in when idle. Signed-off-by: Morten Rasmussen --- kernel/sched/fair.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9720f04..353e2d0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4254,6 +4254,19 @@ static inline bool energy_aware(void) =09return sched_feat(ENERGY_AWARE); } =20 +/* + * Returns the index of the most likely idle-state that the sched_group is= in + * when idle. The index can be used to identify the idle-state in the + * sched_group_energy idle_states list. + * + * This is currently just a placeholder. The information needs to come fro= m + * cpuidle. + */ +static inline int likely_idle_state_idx(struct sched_group *sg) +{ +=09return 0; +} + static int wake_wide(struct task_struct *p) { =09int factor =3D this_cpu_read(sd_llc_size); --=20 1.7.9.5