Re: [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info

From: Vincent Guittot
Date: Tue Apr 01 2014 - 05:06:52 EST

Next message: James Hogan: "[GIT PULL] Metag architecture changes for v3.15"
Previous message: Ingo Molnar: "[GIT PULL] x86/threadinfo changes for v3.15"
In reply to: Daniel Lezcano: "Re: [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info"
Next in thread: Rafael J. Wysocki: "Re: [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On 1 April 2014 09:43, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote:
> On 04/01/2014 09:16 AM, Vincent Guittot wrote:
>>
>> On 31 March 2014 17:55, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote:
>>>
>>> On 03/31/2014 03:52 PM, Vincent Guittot wrote:
>>>>
>>>>
>>>> On 28 March 2014 13:29, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
>>>> wrote:
>>>>>
>>>>>
>>>>> The following patchset provides an interaction between cpuidle and the
>>>>> scheduler.
>>>>>
>>>>> The first patch encapsulate the needed information for the scheduler in
>>>>> a
>>>>> separate cpuidle structure. The second one stores the pointer to this
>>>>> structure
>>>>> when entering idle. The third one, use this information to take the
>>>>> decision to
>>>>> find the idlest cpu.
>>>>>
>>>>> After some basic testing with hackbench, it appears there is an
>>>>> improvement for
>>>>> the performances (small) and for the duration of the idle states (which
>>>>> provides
>>>>> a better power saving).
>>>>>
>>>>> The measurement has been done with the 'idlestat' tool previously
>>>>> posted
>>>>> in this
>>>>> mailing list.
>>>>>
>>>>> So the benefit is good for both sides performance and power saving.
>>>>
>>>>
>>>>
>>>> Hi Daniel,
>>>>
>>>> I have looked at your results and i'm a bit surprised that you have so
>>>> much time in C-state with a test that involved 400 tasks on a dual
>>>> cores HT system. You shouldn't have any CPUs in idle state when
>>>> running hackbench; the total time of core0state in C7-IVB is
>>>> 87932131.00(us), which is quite huge for a bench that runs 44sec. Or
>>>> i'm doing something wrong in the interpretation of the results ?
>>>
>>>
>>>
>>> No, actually I mixed the output of hackbench without being run with
>>> idlestat
>>> or with idlestat.
>>>
>>> The hackbench's results below are without idlestat.
>>>
>>> The idlestat results are consistent and effectively it adds a non
>>> negligeable overhead as it impacts the hackbench results.
>>>
>>> So to summarize, hackbench has been run 4 times.
>>>
>>> 1, 2 : without idlestat, with and without the patchset - hackbench
>>> results
>>> ~42 secs
>>>
>>> 3, 4 : with idlestat, with and without the patchset - hackbench results
>>> ~87
>>> secs
>>>
>>> At the first the glance, the results are consistent but I will double
>>> check
>>> them.
>>>
>>> Do you have a suggestion for a benchmarking program ?
>>
>>
>> We are working on a bench which can generate middle load pattern with
>> idle CPUs but it's not available yet. In the mean time, one bench that
>> plays with idle time is cyclictest, it will not give you performance
>> results but only scheduling latency which might be what you are
>> looking for.
>
>
> Yeah, thanks. I believe I know what is in the rt-tests package :)
>
> What I meant is what kind of values would you like to see with this patchset
> ?

IIUC, you patch tries to improve the wake up latency of a task by
selecting the CPUs with the shallowest C-state, so this metrics seems
to be a good candidate

>
>
>
>
>>>>> The select_idle_sibling could be also improved in the same way.
>>>>>
>>>>> ====================== test with hackbench 3.14-rc8
>>>>> =========================
>>>>>
>>>>> /usr/bin/hackbench -l 10000 -s 4096
>>>>>
>>>>> Running in process mode with 10 groups using 40 file descriptors each
>>>>> (==
>>>>> 400 tasks)
>>>>> Each sender will pass 10000 messages of 4096 bytes
>>>>>
>>>>> Time: 44.433
>>>>>
>>>>> Total trace buffer: 1846688 kB
>>>>> clusterA@state hits total(us) avg(us) min(us) max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> core0@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-IVB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 1396 87932131.00 62988.63 0.00
>>>>> 320146.00
>>>>> cpu0@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 1 14.00 14.00 14.00 14.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 1 262.00 262.00 262.00
>>>>> 262.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 1180 87938177.00 74523.88 1.00
>>>>> 320147.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.0
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu0 wakeups name count
>>>>> irq009 acpi 1
>>>>> cpu1@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 475 87941356.00 185139.70 322.00
>>>>> 1500690.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu1 wakeups name count
>>>>> irq009 acpi 3
>>>>> core1@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-IVB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> cpu2@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 11 288157.00 26196.09 16.00
>>>>> 200060.00
>>>>> C1E-VB 6 221601.00 36933.50 79.00
>>>>> 200066.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 950 87417466.00 92018.39 19.00
>>>>> 200074.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 2 34.00 17.00 11.00 23.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 745 18800.00 25.23 2.00
>>>>> 156.00
>>>>> cpu2 wakeups name count
>>>>> irq019 ahci 50
>>>>> irq009 acpi 17
>>>>> cpu3@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu3 wakeups name count
>>>>>
>>>>> ================ test with hackbench 3.14-rc8 + patchset
>>>>> ====================
>>>>>
>>>>> /usr/bin/hackbench -l 10000 -s 4096
>>>>>
>>>>> Running in process mode with 10 groups using 40 file descriptors each
>>>>> (==
>>>>> 400 tasks)
>>>>> Each sender will pass 10000 messages of 4096 bytes
>>>>>
>>>>> Time: 42.179
>>>>>
>>>>> Total trace buffer: 1846688 kB
>>>>> clusterA@state hits total(us) avg(us) min(us) max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> core0@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-IVB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 880 89157590.00 101315.44 0.00
>>>>> 400184.00
>>>>> cpu0@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 1 233.00 233.00 233.00
>>>>> 233.00
>>>>> C3-IVB 1 260.00 260.00 260.00
>>>>> 260.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 700 89162006.00 127374.29 182.00
>>>>> 400187.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu0 wakeups name count
>>>>> irq009 acpi 2
>>>>> cpu1@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 334 89164805.00 266960.49 1.00
>>>>> 1500677.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu1 wakeups name count
>>>>> irq009 acpi 6
>>>>> core1@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-IVB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> cpu2@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 19 2169047.00 114160.37 18.00
>>>>> 999129.00
>>>>> C1E-IB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 376 86993307.00 231365.18 20.00
>>>>> 1500682.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu2 wakeups name count
>>>>> irq009 acpi 32
>>>>> irq019 ahci 45
>>>>> cpu3@state hits total(us) avg(us) min(us)
>>>>> max(us)
>>>>> POLL 0 0.00 0.00 0.00 0.00
>>>>> C1-IVB 0 0.00 0.00 0.00 0.00
>>>>> C1E-VB 0 0.00 0.00 0.00 0.00
>>>>> C3-IVB 0 0.00 0.00 0.00 0.00
>>>>> C6-IVB 0 0.00 0.00 0.00 0.00
>>>>> C7-IVB 0 0.00 0.00 0.00 0.00
>>>>> 1701 0 0.00 0.00 0.00 0.00
>>>>> 1700 0 0.00 0.00 0.00 0.00
>>>>> 1600 0 0.00 0.00 0.00 0.00
>>>>> 1500 0 0.00 0.00 0.00 0.00
>>>>> 1400 0 0.00 0.00 0.00 0.00
>>>>> 1300 0 0.00 0.00 0.00 0.00
>>>>> 1200 0 0.00 0.00 0.00 0.00
>>>>> 1100 0 0.00 0.00 0.00 0.00
>>>>> 1000 0 0.00 0.00 0.00 0.00
>>>>> 900 0 0.00 0.00 0.00 0.00
>>>>> 800 0 0.00 0.00 0.00 0.00
>>>>> 782 0 0.00 0.00 0.00 0.00
>>>>> cpu3 wakeups name count
>>>>>
>>>>>
>>>>> Daniel Lezcano (3):
>>>>> cpuidle: encapsulate power info in a separate structure
>>>>> idle: store the idle state the cpu is
>>>>> sched/fair: use the idle state info to choose the idlest cpu
>>>>>
>>>>> arch/arm/include/asm/cpuidle.h | 6 +-
>>>>> arch/arm/mach-exynos/cpuidle.c | 4 +-
>>>>> drivers/acpi/processor_idle.c | 4 +-
>>>>> drivers/base/power/domain.c | 6 +-
>>>>> drivers/cpuidle/cpuidle-at91.c | 4 +-
>>>>> drivers/cpuidle/cpuidle-big_little.c | 9 +--
>>>>> drivers/cpuidle/cpuidle-calxeda.c | 6 +-
>>>>> drivers/cpuidle/cpuidle-kirkwood.c | 4 +-
>>>>> drivers/cpuidle/cpuidle-powernv.c | 8 +--
>>>>> drivers/cpuidle/cpuidle-pseries.c | 12 ++--
>>>>> drivers/cpuidle/cpuidle-ux500.c | 14 ++---
>>>>> drivers/cpuidle/cpuidle-zynq.c | 4 +-
>>>>> drivers/cpuidle/driver.c | 6 +-
>>>>> drivers/cpuidle/governors/ladder.c | 14 +++--
>>>>> drivers/cpuidle/governors/menu.c | 8 +--
>>>>> drivers/cpuidle/sysfs.c | 2 +-
>>>>> drivers/idle/intel_idle.c | 112
>>>>> +++++++++++++++++-----------------
>>>>> include/linux/cpuidle.h | 10 ++-
>>>>> kernel/sched/fair.c | 46 ++++++++++++--
>>>>> kernel/sched/idle.c | 17 +++++-
>>>>> kernel/sched/sched.h | 5 ++
>>>>> 21 files changed, 180 insertions(+), 121 deletions(-)
>>>>>
>>>>> --
>>>>> 1.7.9.5
>>>>>
>>>
>>>
>>> --
>>> <http://www.linaro.org/> Linaro.org â Open source software for ARM SoCs
>>>
>>> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
>>> <http://twitter.com/#!/linaroorg> Twitter |
>>> <http://www.linaro.org/linaro-blog/> Blog
>>>
>
>
> --
> <http://www.linaro.org/> Linaro.org â Open source software for ARM SoCs
>
> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: James Hogan: "[GIT PULL] Metag architecture changes for v3.15"
Previous message: Ingo Molnar: "[GIT PULL] x86/threadinfo changes for v3.15"
In reply to: Daniel Lezcano: "Re: [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info"
Next in thread: Rafael J. Wysocki: "Re: [RFC PATCHC 0/3] sched/idle : find the idlest cpu with cpuidle info"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]