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From: Neil Horman <nhorman@tuxdriver.com>
To: Alan Carew <alan.carew@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 06/10] Alternate implementation of librte_power for VM Power Management(Guest).
Date: Mon, 22 Sep 2014 15:17:53 -0400
Message-ID: <20140922191753.GH25406@hmsreliant.think-freely.org> (raw)
In-Reply-To: <1411410879-28872-7-git-send-email-alan.carew@intel.com>

On Mon, Sep 22, 2014 at 07:34:35PM +0100, Alan Carew wrote:
> Re-using the host based librte_power API the alternate implementation uses
> the guest channel API to forward request for frequency changes to the host
> monitor.
> A subset of the librte_power API is supported:
>  rte_power_init(unsigned lcore_id)
>  rte_power_exit(unsigned lcore_id)
>  rte_power_freq_up(unsigned lcore_id)
>  rte_power_freq_down(unsigned lcore_id)
>  rte_power_freq_min(unsigned lcore_id)
>  rte_power_freq_max(unsigned lcore_id)
> 
> The other unsupported APIs from librte_power return -ENOTSUP.
> 
> Signed-off-by: Alan Carew <alan.carew@intel.com>
> ---
>  lib/librte_power_vm/Makefile    |  49 ++++++++++++++
>  lib/librte_power_vm/rte_power.c | 146 ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 195 insertions(+)
>  create mode 100644 lib/librte_power_vm/Makefile
>  create mode 100644 lib/librte_power_vm/rte_power.c
> 
NAK.
This is a bad design choice.  Creating an alternate library with all the same
symbols in place prevents an application from compiling in support for both host
and guest power management in parallel (i.e. if an app wants to be able to do
power management in either environment, and only gets built once, it won't
work).

In fact, linking a statically built library with both CONFIG_RTE_LIBRTE_POWER=y
and CONFIG_RTE_LIBRTE_POWER_VM=y yields the following link-time build break:

LD test
/home/nhorman/git/dpdk/build/lib/librte_power.a(guest_channel.o): In function
`guest_channel_host_connect':
guest_channel.c:(.text+0x0): multiple definition of `guest_channel_host_connect'
/home/nhorman/git/dpdk/build/lib/librte_power.a(guest_channel.o):guest_channel.c:(.text+0x0):
first defined here
/home/nhorman/git/dpdk/build/lib/librte_power.a(guest_channel.o): In function
`guest_channel_send_msg':
guest_channel.c:(.text+0x370): multiple definition of `guest_channel_send_msg'
....
Ad nauseum.

What you should do is merge this functionality in with the existing librte power
library, and make the choice of implementation a run time decision, so theres
only a single public facing API symbol set, and both implementations can
coexist, getting chosen at run time (via initialization config option,
environment detection, etc).  Konstantin and I had a simmilar discussion
regarding the ACL library and the use of the match function.  I think we came up
with some reasonably performant solutions.

Neil

  reply	other threads:[~2014-09-22 19:11 UTC|newest]

Thread overview: 97+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-22 18:34 [dpdk-dev] [PATCH 00/10] VM Power Management Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 01/10] Channel Manager and Monitor for VM Power Management(Host) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 02/10] VM Power Management CLI(Host) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 03/10] CPU Frequency Power Management(Host) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 04/10] " Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 05/10] VM communication channels for VM Power Management(Guest) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 06/10] Alternate implementation of librte_power " Alan Carew
2014-09-22 19:17   ` Neil Horman [this message]
2014-09-23  7:48     ` Carew, Alan
2014-09-22 18:34 ` [dpdk-dev] [PATCH 07/10] Packet format for VM Power Management(Host and Guest) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 08/10] Build system integration for VM Power Management(Guest and Host) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 09/10] VM Power Management Unit Tests(Guest) Alan Carew
2014-09-22 18:34 ` [dpdk-dev] [PATCH 10/10] VM Power Management CLI(Guest) Alan Carew
2014-09-24 17:26 ` [dpdk-dev] [PATCH v2 00/10] VM Power Management Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 01/10] Channel Manager and Monitor for VM Power Management(Host) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 02/10] VM Power Management CLI(Host) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 03/10] CPU Frequency Power Management(Host) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 04/10] VM Power Management application and Makefile Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 05/10] VM Power Management CLI(Guest) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 06/10] VM communication channels for VM Power Management(Guest) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 07/10] librte_power common interface for Guest and Host Alan Carew
2014-09-25 10:10     ` Neil Horman
2014-09-25 17:06       ` Carew, Alan
2014-09-25 17:49         ` Neil Horman
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 08/10] Packet format for VM Power Management(Host and Guest) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 09/10] Build system integration for VM Power Management(Guest and Host) Alan Carew
2014-09-24 17:26   ` [dpdk-dev] [PATCH v2 10/10] VM Power Management Unit Tests Alan Carew
2014-09-25  2:56   ` [dpdk-dev] [PATCH v2 00/10] VM Power Management Liu, Yong
2014-09-29 15:18   ` [dpdk-dev] [PATCH v3 " Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 01/10] Channel Manager and Monitor for VM Power Management(Host) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 02/10] VM Power Management CLI(Host) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 03/10] CPU Frequency Power Management(Host) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 04/10] VM Power Management application and Makefile Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 05/10] VM Power Management CLI(Guest) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 06/10] VM communication channels for VM Power Management(Guest) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 07/10] librte_power common interface for Guest and Host Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 08/10] Packet format for VM Power Management(Host and Guest) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 09/10] Build system integration for VM Power Management(Guest and Host) Alan Carew
2014-09-29 15:18     ` [dpdk-dev] [PATCH v3 10/10] VM Power Management Unit Tests Alan Carew
2014-09-29 17:29     ` [dpdk-dev] [PATCH v3 00/10] VM Power Management Neil Horman
2014-10-12 19:36     ` [dpdk-dev] [PATCH v4 " Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 01/10] Channel Manager and Monitor for VM Power Management(Host) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 02/10] VM Power Management CLI(Host) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 03/10] CPU Frequency Power Management(Host) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 04/10] VM Power Management application and Makefile Alan Carew
2014-10-16 18:28         ` De Lara Guarch, Pablo
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 05/10] VM Power Management CLI(Guest) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 06/10] VM communication channels for VM Power Management(Guest) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 07/10] librte_power common interface for Guest and Host Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 08/10] Packet format for VM Power Management(Host and Guest) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 09/10] Build system integration for VM Power Management(Guest and Host) Alan Carew
2014-10-12 19:36       ` [dpdk-dev] [PATCH v4 10/10] VM Power Management Unit Tests Alan Carew
2014-10-13  6:17       ` [dpdk-dev] [PATCH v4 00/10] VM Power Management Liu, Yong
2014-10-13 20:26       ` Thomas Monjalon
2014-10-14 12:37         ` Carew, Alan
2014-10-14 15:03           ` Thomas Monjalon
2014-10-16 15:21             ` Carew, Alan
2014-10-28 15:21               ` Thomas Monjalon
2014-11-10  9:05                 ` Carew, Alan
2014-11-10 17:54                   ` O'driscoll, Tim
2014-11-21 23:51                     ` Zhu, Heqing
2014-11-22 17:17                     ` Vincent JARDIN
2014-12-09 17:35                       ` Paolo Bonzini
2014-12-11 23:18                         ` Thomas Monjalon
2014-12-12 13:00                           ` Carew, Alan
2014-12-12 14:50                             ` Paolo Bonzini
2014-12-12 16:10                               ` Thomas Monjalon
2014-12-12 16:13                                 ` Paolo Bonzini
2014-11-21 17:42       ` [dpdk-dev] [PATCH v5 00/10] Virtual Machine " Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 01/10] Channel Manager and Monitor for VM Power Management(Host) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 02/10] VM Power Management CLI(Host) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 03/10] CPU Frequency Power Management(Host) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 04/10] VM Power Management application and Makefile Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 05/10] VM Power Management CLI(Guest) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 06/10] VM communication channels for VM Power Management(Guest) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 07/10] librte_power common interface for Guest and Host Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 08/10] Packet format for VM Power Management(Host and Guest) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 09/10] Build system integration for VM Power Management(Guest and Host) Pablo de Lara
2014-11-21 17:42         ` [dpdk-dev] [PATCH v5 10/10] VM Power Management Unit Tests Pablo de Lara
2014-11-25 16:18         ` [dpdk-dev] [PATCH v6 00/10] Virtual Machine Power Management Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 01/10] Channel Manager and Monitor for VM Power Management(Host) Pablo de Lara
2014-11-29 15:21             ` Neil Horman
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 02/10] VM Power Management CLI(Host) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 03/10] CPU Frequency Power Management(Host) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 04/10] VM Power Management application and Makefile Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 05/10] VM Power Management CLI(Guest) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 06/10] VM communication channels for VM Power Management(Guest) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 07/10] librte_power common interface for Guest and Host Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 08/10] Packet format for VM Power Management(Host and Guest) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 09/10] Build system integration for VM Power Management(Guest and Host) Pablo de Lara
2014-11-25 16:18           ` [dpdk-dev] [PATCH v6 10/10] VM Power Management Unit Tests Pablo de Lara
2014-11-26 16:41           ` [dpdk-dev] [PATCH v6 00/10] Virtual Machine Power Management Thomas Monjalon
2014-11-10  9:19     ` [dpdk-dev] [PATCH v2] librte_cmdline: FreeBSD Fix oveflow when size of command result structure is greater than BUFSIZ Alan Carew
2014-12-05 14:16       ` Olivier MATZ
2014-12-05 14:19         ` [dpdk-dev] [PATCH v3] " Olivier Matz
2014-12-05 15:51           ` Bruce Richardson
2014-12-05 15:58             ` Thomas Monjalon

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