From: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
To: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>,
Nathan Lynch <nathanl@linux.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 0/5] Track and expose idle PURR and SPURR ticks
Date: Tue, 7 Apr 2020 16:54:44 +0530 [thread overview]
Message-ID: <a1feda38-9488-a025-4a38-e4785bf7405d@linux.vnet.ibm.com> (raw)
In-Reply-To: <1586249263-14048-1-git-send-email-ego@linux.vnet.ibm.com>
On 4/7/20 2:17 PM, Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>
> Hi,
>
> This is the fifth version of the patches to track and expose idle PURR
> and SPURR ticks. These patches are required by tools such as lparstat
> to compute system utilization for capacity planning purposes.
>
> The previous versions can be found here:
> v4: https://lkml.org/lkml/2020/3/27/323
> v3: https://lkml.org/lkml/2020/3/11/331
> v2: https://lkml.org/lkml/2020/2/21/21
> v1: https://lore.kernel.org/patchwork/cover/1159341/
>
> They changes from v4 are:
>
> - As suggested by Naveen, moved the functions read_this_idle_purr()
> and read_this_idle_spurr() from Patch 2 and Patch 3 respectively
> to Patch 4 where it is invoked.
>
> - Dropped Patch 6 which cached the values of purr, spurr,
> idle_purr, idle_spurr in order to minimize the number of IPIs
> sent.
>
> - Updated the dates for the idle_purr, idle_spurr in the
> Documentation Patch 5.
>
> Motivation:
> ===========
> On PSeries LPARs, the data centers planners desire a more accurate
> view of system utilization per resource such as CPU to plan the system
> capacity requirements better. Such accuracy can be obtained by reading
> PURR/SPURR registers for CPU resource utilization.
>
> Tools such as lparstat which are used to compute the utilization need
> to know [S]PURR ticks when the cpu was busy or idle. The [S]PURR
> counters are already exposed through sysfs. We already account for
> PURR ticks when we go to idle so that we can update the VPA area. This
> patchset extends support to account for SPURR ticks when idle, and
> expose both via per-cpu sysfs files.
>
> These patches are required for enhancement to the lparstat utility
> that compute the CPU utilization based on PURR and SPURR which can be
> found here :
> https://groups.google.com/forum/#!topic/powerpc-utils-devel/fYRo69xO9r4
>
>
> With the patches, when lparstat is run on a LPAR running CPU-Hogs,
> =========================================================================
> sudo ./src/lparstat -E 1 3
>
> System Configuration
> type=Dedicated mode=Capped smt=8 lcpu=2 mem=4834112 kB cpus=0 ent=2.00
>
> ---Actual--- -Normalized-
> %busy %idle Frequency %busy %idle
> ------ ------ ------------- ------ ------
> 1 99.99 0.00 3.35GHz[111%] 110.99 0.00
> 2 100.00 0.00 3.35GHz[111%] 111.01 0.00
> 3 100.00 0.00 3.35GHz[111%] 111.00 0.00
>
> With patches, when lparstat is run on and idle LPAR
> =========================================================================
> System Configuration
> type=Dedicated mode=Capped smt=8 lcpu=2 mem=4834112 kB cpus=0 ent=2.00
> ---Actual--- -Normalized-
> %busy %idle Frequency %busy %idle
> ------ ------ ------------- ------ ------
> 1 0.15 99.84 2.17GHz[ 72%] 0.11 71.89
> 2 0.24 99.76 2.11GHz[ 70%] 0.18 69.82
> 3 0.24 99.75 2.11GHz[ 70%] 0.18 69.81
>
> Gautham R. Shenoy (5):
> powerpc: Move idle_loop_prolog()/epilog() functions to header file
> powerpc/idle: Store PURR snapshot in a per-cpu global variable
> powerpc/pseries: Account for SPURR ticks on idle CPUs
> powerpc/sysfs: Show idle_purr and idle_spurr for every CPU
> Documentation: Document sysfs interfaces purr, spurr, idle_purr,
> idle_spurr
>
> Documentation/ABI/testing/sysfs-devices-system-cpu | 39 +++++++++
> arch/powerpc/include/asm/idle.h | 93 ++++++++++++++++++++++
> arch/powerpc/kernel/sysfs.c | 82 ++++++++++++++++++-
> arch/powerpc/platforms/pseries/setup.c | 8 +-
> drivers/cpuidle/cpuidle-pseries.c | 39 ++-------
> 5 files changed, 224 insertions(+), 37 deletions(-)
> create mode 100644 arch/powerpc/include/asm/idle.h
>
Hi Gautham,
Thanks for working on it, I tested it using the lparstat patches posted at:
https://groups.google.com/forum/#!topic/powerpc-utils-devel/_imHP1Guw3c
On idle system:
===============
sudo ./src/lparstat -E 1 3
System Configuration
type=Dedicated mode=Capped smt=8 lcpu=2 mem=4324928 kB cpus=0 ent=2.00
---Actual--- -Normalized-
%busy %idle Frequency %busy %idle
------ ------ ------------- ------ ------
0.27 99.74 2.11GHz[ 70%] 0.24 69.76
0.57 99.43 2.17GHz[ 72%] 0.43 71.57
0.52 99.47 2.11GHz[ 70%] 0.38 69.62
On system running N while(1) (N == online cpus)
===============================================
sudo ./src/lparstat -E 1 3
System Configuration
type=Dedicated mode=Capped smt=8 lcpu=2 mem=4324928 kB cpus=0 ent=2.00
---Actual--- -Normalized-
%busy %idle Frequency %busy %idle
------ ------ ------------- ------ ------
99.99 0.00 3.35GHz[111%] 110.99 0.00
100.00 0.00 3.35GHz[111%] 111.00 0.00
100.00 0.00 3.35GHz[111%] 111.00 0.00
For the series:
Reviewed-and-Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
--
Kamalesh
next prev parent reply other threads:[~2020-04-07 11:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 8:47 [PATCH v5 0/5] Track and expose idle PURR and SPURR ticks Gautham R. Shenoy
2020-04-07 8:47 ` [PATCH v5 1/5] powerpc: Move idle_loop_prolog()/epilog() functions to header file Gautham R. Shenoy
2020-05-06 2:51 ` Michael Ellerman
2020-04-07 8:47 ` [PATCH v5 2/5] powerpc/idle: Store PURR snapshot in a per-cpu global variable Gautham R. Shenoy
2020-04-07 8:47 ` [PATCH v5 3/5] powerpc/pseries: Account for SPURR ticks on idle CPUs Gautham R. Shenoy
2020-04-07 8:47 ` [PATCH v5 4/5] powerpc/sysfs: Show idle_purr and idle_spurr for every CPU Gautham R. Shenoy
2020-04-07 8:47 ` [PATCH v5 5/5] Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr Gautham R. Shenoy
2020-04-07 9:05 ` [PATCH v5 0/5] Track and expose idle PURR and SPURR ticks Naveen N. Rao
2020-04-07 11:24 ` Kamalesh Babulal [this message]
2020-04-20 22:46 ` Tyrel Datwyler
2020-04-23 10:02 ` Gautham R Shenoy
2020-04-30 2:34 ` Michael Ellerman
2020-04-30 4:16 ` Gautham R Shenoy
2020-05-01 5:50 ` Gautham R Shenoy
2020-04-21 13:30 ` Nathan Lynch
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