From: Morten Rasmussen <morten.rasmussen@arm.com>
To: peterz@infradead.org, mingo@redhat.com
Cc: dietmar.eggemann@arm.com, yuyang.du@intel.com,
vincent.guittot@linaro.org, mgalbraith@suse.de,
linux-kernel@vger.kernel.org,
Morten Rasmussen <morten.rasmussen@arm.com>
Subject: [PATCH 00/16] sched: Clean-ups and asymmetric cpu capacity support
Date: Mon, 23 May 2016 11:58:42 +0100 [thread overview]
Message-ID: <1464001138-25063-1-git-send-email-morten.rasmussen@arm.com> (raw)
Hi,
The scheduler is currently not doing much to help performance on systems with
asymmetric compute capacities (read ARM big.LITTLE). This series improves the
situation with a few tweaks mainly to the task wake-up path that considers
compute capacity at wake-up and not just whether a cpu is idle for these
systems. This gives us consistent, and potentially higher, throughput in
partially utilized scenarious. SMP behaviour and performance should be
unaffected.
Test 0:
for i in `seq 1 10`; \
do sysbench --test=cpu --max-time=3 --num-threads=1 run; \
done \
| awk '{if ($4=="events:") {print $5; sum +=$5; runs +=1}} \
END {print "Average events: " sum/runs}'
Target: ARM TC2 (2xA15+3xA7)
(Higher is better)
tip: Average events: 150.2
patch: Average events: 217.9
Test 1:
perf stat --null --repeat 10 -- \
perf bench sched messaging -g 50 -l 5000
Target: Intel IVB-EP (2*10*2)
tip: 4.831538935 seconds time elapsed ( +- 1.58% )
patch: 4.839951382 seconds time elapsed ( +- 1.01% )
Target: ARM TC2 A7-only (3xA7) (-l 1000)
tip: 61.406552538 seconds time elapsed ( +- 0.12% )
patch: 61.589263159 seconds time elapsed ( +- 0.22% )
Active migration of tasks away from small capacity cpus isn't addressed
in this set although it is necessary for consistent throughput in other
scenarios on asymmetric cpu capacity systems.
Patch 1-4: Generic fixes and clean-ups.
Patch 5-13: Improve capacity awareness.
Patch 14-16: Arch features for arm to enable asymmetric capacity support.
Dietmar Eggemann (1):
sched: Store maximum per-cpu capacity in root domain
Morten Rasmussen (15):
sched: Fix power to capacity renaming in comment
sched/fair: Consistent use of prev_cpu in wakeup path
sched/fair: Disregard idle task wakee_flips in wake_wide
sched/fair: Optimize find_idlest_cpu() when there is no choice
sched: Introduce SD_ASYM_CPUCAPACITY sched_domain topology flag
sched: Disable WAKE_AFFINE for asymmetric configurations
sched: Make SD_BALANCE_WAKE a topology flag
sched/fair: Let asymmetric cpu configurations balance at wake-up
sched/fair: Compute task/cpu utilization at wake-up more correctly
sched/fair: Consider spare capacity in find_idlest_group()
sched: Add per-cpu max capacity to sched_group_capacity
sched/fair: Avoid pulling tasks from non-overloaded higher capacity
groups
arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms
arm: Set SD_BALANCE_WAKE flag for asymmetric capacity systems
arm: Update arch_scale_cpu_capacity() to reflect change to define
arch/arm/include/asm/topology.h | 5 +
arch/arm/kernel/topology.c | 25 ++++-
include/linux/sched.h | 3 +-
kernel/sched/core.c | 25 ++++-
kernel/sched/fair.c | 217 ++++++++++++++++++++++++++++++++++++----
kernel/sched/sched.h | 5 +-
6 files changed, 250 insertions(+), 30 deletions(-)
--
1.9.1
next reply other threads:[~2016-05-23 10:58 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-23 10:58 Morten Rasmussen [this message]
2016-05-23 10:58 ` [PATCH 01/16] sched: Fix power to capacity renaming in comment Morten Rasmussen
2016-05-23 10:58 ` [PATCH 02/16] sched/fair: Consistent use of prev_cpu in wakeup path Morten Rasmussen
2016-06-01 19:49 ` Peter Zijlstra
2016-05-23 10:58 ` [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide Morten Rasmussen
2016-05-23 11:12 ` Mike Galbraith
2016-05-23 12:00 ` Morten Rasmussen
2016-05-23 13:00 ` Mike Galbraith
2016-05-23 14:10 ` Morten Rasmussen
2016-05-23 15:42 ` Mike Galbraith
2016-05-23 23:17 ` Yuyang Du
2016-05-23 23:04 ` Yuyang Du
2016-06-01 19:57 ` Peter Zijlstra
2016-06-02 8:05 ` Peter Zijlstra
2016-06-07 12:08 ` Morten Rasmussen
2016-05-23 10:58 ` [PATCH 04/16] sched/fair: Optimize find_idlest_cpu() when there is no choice Morten Rasmussen
2016-05-24 6:29 ` Mike Galbraith
2016-05-24 8:05 ` Morten Rasmussen
2016-05-24 8:12 ` Mike Galbraith
2016-06-01 19:59 ` Peter Zijlstra
2016-06-07 14:25 ` Morten Rasmussen
2016-05-23 10:58 ` [PATCH 05/16] sched: Introduce SD_ASYM_CPUCAPACITY sched_domain topology flag Morten Rasmussen
2016-05-23 10:58 ` [PATCH 06/16] sched: Disable WAKE_AFFINE for asymmetric configurations Morten Rasmussen
2016-05-24 9:10 ` Vincent Guittot
2016-05-24 10:29 ` Morten Rasmussen
2016-05-24 12:12 ` Vincent Guittot
2016-05-24 13:16 ` Morten Rasmussen
2016-05-24 13:27 ` Vincent Guittot
2016-05-24 13:36 ` Morten Rasmussen
2016-05-24 13:52 ` Vincent Guittot
2016-05-24 15:02 ` Morten Rasmussen
2016-05-24 15:53 ` Vincent Guittot
2016-05-25 9:12 ` Morten Rasmussen
2016-05-26 6:45 ` Vincent Guittot
2016-06-07 16:50 ` Morten Rasmussen
2016-05-23 10:58 ` [PATCH 07/16] sched: Make SD_BALANCE_WAKE a topology flag Morten Rasmussen
2016-05-24 23:52 ` Yuyang Du
2016-05-25 9:27 ` Morten Rasmussen
2016-06-01 20:18 ` Peter Zijlstra
2016-06-08 8:45 ` Morten Rasmussen
2016-05-23 10:58 ` [PATCH 08/16] sched: Store maximum per-cpu capacity in root domain Morten Rasmussen
2016-05-23 10:58 ` [PATCH 09/16] sched/fair: Let asymmetric cpu configurations balance at wake-up Morten Rasmussen
2016-05-24 0:04 ` Yuyang Du
2016-05-24 8:10 ` Morten Rasmussen
2016-05-24 7:03 ` Mike Galbraith
2016-05-24 7:15 ` Mike Galbraith
2016-05-25 6:57 ` Wanpeng Li
2016-05-25 9:49 ` Morten Rasmussen
2016-05-25 10:29 ` Wanpeng Li
2016-05-25 10:54 ` Morten Rasmussen
2016-05-25 11:18 ` Wanpeng Li
2016-06-02 14:21 ` Peter Zijlstra
2016-06-08 11:29 ` Morten Rasmussen
2016-06-08 14:36 ` Peter Zijlstra
2016-05-23 10:58 ` [PATCH 10/16] sched/fair: Compute task/cpu utilization at wake-up more correctly Morten Rasmussen
2016-05-23 10:58 ` [PATCH 11/16] sched/fair: Consider spare capacity in find_idlest_group() Morten Rasmussen
2016-05-23 10:58 ` [PATCH 12/16] sched: Add per-cpu max capacity to sched_group_capacity Morten Rasmussen
2016-05-23 10:58 ` [PATCH 13/16] sched/fair: Avoid pulling tasks from non-overloaded higher capacity groups Morten Rasmussen
2016-05-23 10:58 ` [PATCH 14/16] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms Morten Rasmussen
2016-05-23 10:58 ` [PATCH 15/16] arm: Set SD_BALANCE_WAKE flag for asymmetric capacity systems Morten Rasmussen
2016-05-23 10:58 ` [PATCH 16/16] arm: Update arch_scale_cpu_capacity() to reflect change to define Morten Rasmussen
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