From: Quentin Perret <quentin.perret@arm.com>
To: peterz@infradead.org, rjw@rjwysocki.net,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: gregkh@linuxfoundation.org, mingo@redhat.com,
dietmar.eggemann@arm.com, morten.rasmussen@arm.com,
chris.redpath@arm.com, patrick.bellasi@arm.com,
valentin.schneider@arm.com, vincent.guittot@linaro.org,
thara.gopinath@linaro.org, viresh.kumar@linaro.org,
tkjos@google.com, joel@joelfernandes.org, smuckle@google.com,
adharmap@codeaurora.org, skannan@codeaurora.org,
pkondeti@codeaurora.org, juri.lelli@redhat.com,
edubezval@gmail.com, srinivas.pandruvada@linux.intel.com,
currojerez@riseup.net, javi.merino@kernel.org,
quentin.perret@arm.com
Subject: [PATCH v9 06/15] sched/topology: Lowest CPU asymmetry sched_domain level pointer
Date: Mon, 19 Nov 2018 14:18:48 +0000 [thread overview]
Message-ID: <20181119141857.8625-7-quentin.perret@arm.com> (raw)
In-Reply-To: <20181119141857.8625-1-quentin.perret@arm.com>
Add another member to the family of per-cpu sched_domain shortcut
pointers. This one, sd_asym_cpucapacity, points to the lowest level
at which the SD_ASYM_CPUCAPACITY flag is set. While at it, rename the
sd_asym shortcut to sd_asym_packing to avoid confusions.
Generally speaking, the largest opportunity to save energy via
scheduling comes from a smarter exploitation of heterogeneous platforms
(i.e. big.LITTLE). Consequently, the sd_asym_cpucapacity shortcut will
be used at first as the lowest domain where Energy-Aware Scheduling
(EAS) should be applied. For example, it is possible to apply EAS within
a socket on a multi-socket system, as long as each socket has an
asymmetric topology. Energy-aware cross-sockets wake-up balancing will
only happen when the system is over-utilized, or this_cpu and prev_cpu
are in different sockets.
cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
---
kernel/sched/fair.c | 2 +-
kernel/sched/sched.h | 3 ++-
kernel/sched/topology.c | 8 ++++++--
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e30dea59d215..6c42f3e075b9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9299,7 +9299,7 @@ static void nohz_balancer_kick(struct rq *rq)
}
}
- sd = rcu_dereference(per_cpu(sd_asym, cpu));
+ sd = rcu_dereference(per_cpu(sd_asym_packing, cpu));
if (sd) {
for_each_cpu(i, sched_domain_span(sd)) {
if (i == cpu ||
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 735302641c8b..c6e32d4684bc 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1305,7 +1305,8 @@ DECLARE_PER_CPU(int, sd_llc_size);
DECLARE_PER_CPU(int, sd_llc_id);
DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
DECLARE_PER_CPU(struct sched_domain *, sd_numa);
-DECLARE_PER_CPU(struct sched_domain *, sd_asym);
+DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing);
+DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity);
extern struct static_key_false sched_asym_cpucapacity;
struct sched_group_capacity {
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 649d4aad4002..76ff03f51fa9 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -508,7 +508,8 @@ DEFINE_PER_CPU(int, sd_llc_size);
DEFINE_PER_CPU(int, sd_llc_id);
DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
DEFINE_PER_CPU(struct sched_domain *, sd_numa);
-DEFINE_PER_CPU(struct sched_domain *, sd_asym);
+DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing);
+DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity);
DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity);
static void update_top_cache_domain(int cpu)
@@ -534,7 +535,10 @@ static void update_top_cache_domain(int cpu)
rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
sd = highest_flag_domain(cpu, SD_ASYM_PACKING);
- rcu_assign_pointer(per_cpu(sd_asym, cpu), sd);
+ rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd);
+
+ sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY);
+ rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd);
}
/*
--
2.19.1
next prev parent reply other threads:[~2018-11-19 14:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-19 14:18 [PATCH v9 00/15] Energy Aware Scheduling Quentin Perret
2018-11-19 14:18 ` [PATCH v9 01/15] sched: Relocate arch_scale_cpu_capacity Quentin Perret
2018-11-19 14:18 ` [PATCH v9 02/15] sched/cpufreq: Prepare schedutil for Energy Aware Scheduling Quentin Perret
2018-11-20 4:46 ` Viresh Kumar
2018-11-20 15:25 ` Peter Zijlstra
2018-11-20 15:53 ` Quentin Perret
2018-11-19 14:18 ` [PATCH v9 03/15] PM: Introduce an Energy Model management framework Quentin Perret
2018-11-19 14:18 ` [PATCH v9 04/15] PM / EM: Expose the Energy Model in sysfs Quentin Perret
2018-11-19 14:18 ` [PATCH v9 05/15] sched/topology: Reference the Energy Model of CPUs when available Quentin Perret
2018-11-19 14:18 ` Quentin Perret [this message]
2018-11-19 14:18 ` [PATCH v9 07/15] sched/topology: Disable EAS on inappropriate platforms Quentin Perret
2018-11-19 14:18 ` [PATCH v9 08/15] sched/topology: Make Energy Aware Scheduling depend on schedutil Quentin Perret
2018-11-22 14:04 ` Peter Zijlstra
2018-11-22 15:49 ` Rafael J. Wysocki
2018-11-22 15:56 ` Quentin Perret
2018-11-19 14:18 ` [PATCH v9 09/15] sched: Introduce sched_energy_present static key Quentin Perret
2018-11-21 13:08 ` Peter Zijlstra
2018-11-21 15:14 ` Quentin Perret
2018-11-22 9:17 ` Quentin Perret
2018-11-22 9:32 ` Quentin Perret
2018-11-22 10:25 ` Peter Zijlstra
2018-11-22 15:25 ` Quentin Perret
2018-11-22 15:51 ` Rafael J. Wysocki
2018-11-22 15:55 ` Quentin Perret
2018-11-19 14:18 ` [PATCH v9 10/15] sched: Introduce a sysctl for Energy Aware Scheduling Quentin Perret
2018-11-19 14:18 ` [PATCH v9 11/15] sched/fair: Clean-up update_sg_lb_stats parameters Quentin Perret
2018-11-19 14:18 ` [PATCH v9 12/15] sched: Add over-utilization/tipping point indicator Quentin Perret
2018-11-19 14:18 ` [PATCH v9 13/15] sched/fair: Introduce an energy estimation helper function Quentin Perret
2018-11-21 14:28 ` Peter Zijlstra
2018-11-21 16:05 ` Quentin Perret
2018-11-22 13:56 ` Peter Zijlstra
2018-11-19 14:18 ` [PATCH v9 14/15] sched/fair: Select an energy-efficient CPU on task wake-up Quentin Perret
2018-11-19 14:18 ` [PATCH v9 15/15] OPTIONAL: cpufreq: dt: Register an Energy Model Quentin Perret
2018-11-20 6:19 ` Viresh Kumar
2018-11-20 10:01 ` Quentin Perret
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