From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161695AbbBDSb3 (ORCPT ); Wed, 4 Feb 2015 13:31:29 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:41600 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161647AbbBDSbR (ORCPT ); Wed, 4 Feb 2015 13:31:17 -0500 From: Morten Rasmussen To: peterz@infradead.org, mingo@redhat.com Cc: vincent.guittot@linaro.org, dietmar.eggemann@arm.com, yuyang.du@intel.com, preeti@linux.vnet.ibm.com, mturquette@linaro.org, nico@linaro.org, rjw@rjwysocki.net, juri.lelli@arm.com, linux-kernel@vger.kernel.org Subject: [RFCv3 PATCH 22/48] sched: Introduce energy data structures Date: Wed, 4 Feb 2015 18:30:59 +0000 Message-Id: <1423074685-6336-23-git-send-email-morten.rasmussen@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1423074685-6336-1-git-send-email-morten.rasmussen@arm.com> References: <1423074685-6336-1-git-send-email-morten.rasmussen@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dietmar Eggemann The struct sched_group_energy represents the per sched_group related data which is needed for energy aware scheduling. It contains: (1) atomic reference counter for scheduler internal bookkeeping of data allocation and freeing (2) number of elements of the idle state array (3) pointer to the idle state array which comprises 'power consumption' for each idle state (4) number of elements of the capacity state array (5) pointer to the capacity state array which comprises 'compute capacity and power consumption' tuples for each capacity state Allocation and freeing of struct sched_group_energy utilizes the existing infrastructure of the scheduler which is currently used for the other sd hierarchy data structures (e.g. struct sched_domain) as well. That's why struct sd_data is provisioned with a per cpu struct sched_group_energy double pointer. The struct sched_group obtains a pointer to a struct sched_group_energy. The function pointer sched_domain_energy_f is introduced into struct sched_domain_topology_level which will allow the arch to pass a particular struct sched_group_energy from the topology shim layer into the scheduler core. The function pointer sched_domain_energy_f has an 'int cpu' parameter since the folding of two adjacent sd levels via sd degenerate doesn't work for all sd levels. I.e. it is not possible for example to use this feature to provide per-cpu energy in sd level DIE on ARM's TC2 platform. It was discussed that the folding of sd levels approach is preferable over the cpu parameter approach, simply because the user (the arch specifying the sd topology table) can introduce less errors. But since it is not working, the 'int cpu' parameter is the only way out. It's possible to use the folding of sd levels approach for sched_domain_flags_f and the cpu parameter approach for the sched_domain_energy_f at the same time though. With the use of the 'int cpu' parameter, an extra check function has to be provided to make sure that all cpus spanned by a sched group are provisioned with the same energy data. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Dietmar Eggemann --- include/linux/sched.h | 20 ++++++++++++++++++++ kernel/sched/sched.h | 1 + 2 files changed, 21 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index e220a91..2ea93fb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -944,6 +944,23 @@ struct sched_domain_attr { extern int sched_domain_level_max; +struct capacity_state { + unsigned long cap; /* compute capacity */ + unsigned long power; /* power consumption at this compute capacity */ +}; + +struct idle_state { + unsigned long power; /* power consumption in this idle state */ +}; + +struct sched_group_energy { + atomic_t ref; + unsigned int nr_idle_states; /* number of idle states */ + struct idle_state *idle_states; /* ptr to idle state array */ + unsigned int nr_cap_states; /* number of capacity states */ + struct capacity_state *cap_states; /* ptr to capacity state array */ +}; + struct sched_group; struct sched_domain { @@ -1042,6 +1059,7 @@ bool cpus_share_cache(int this_cpu, int that_cpu); typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); typedef int (*sched_domain_flags_f)(void); +typedef const struct sched_group_energy *(*sched_domain_energy_f)(int cpu); #define SDTL_OVERLAP 0x01 @@ -1049,11 +1067,13 @@ struct sd_data { struct sched_domain **__percpu sd; struct sched_group **__percpu sg; struct sched_group_capacity **__percpu sgc; + struct sched_group_energy **__percpu sge; }; struct sched_domain_topology_level { sched_domain_mask_f mask; sched_domain_flags_f sd_flags; + sched_domain_energy_f energy; int flags; int numa_level; struct sd_data data; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 208237f..0e9dcc6 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -817,6 +817,7 @@ struct sched_group { unsigned int group_weight; struct sched_group_capacity *sgc; + struct sched_group_energy *sge; /* * The CPUs this group covers. -- 1.9.1