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From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: "Carew, Alan" <alan.carew@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v4 00/10] VM Power Management
Date: Tue, 14 Oct 2014 17:03:41 +0200
Message-ID: <3349663.LNtcecTXb3@xps13> (raw)
In-Reply-To: <0E29434AEE0C3A4180987AB476A6F6306D28093B@IRSMSX109.ger.corp.intel.com>

2014-10-14 12:37, Carew, Alan:
> > > The following patches add two DPDK sample applications and an alternate
> > > implementation of librte_power for use in virtualized environments.
> > > The idea is to provide librte_power functionality from within a VM to address
> > > the lack of MSRs to facilitate frequency changes from within a VM.
> > > It is ideally suited for Haswell which provides per core frequency scaling.
> > >
> > > The current librte_power affects frequency changes via the acpi-cpufreq
> > > 'userspace' power governor, accessed via sysfs.
> > 
> > Something was preventing me from looking deeper in this big codebase,
> > but I didn't know what sounds weird.
> > Now I realize: the real problem is that virtualization transparency is
> > broken for power management. So the right thing to do is to fix it in
> > KVM. I think all this patchset is a huge workaround.
> > 
> > Did you try to fix it with Qemu/KVM?
> 
> When looking at the libvirt API it would seem to be a natural fit to have
> power management sitting there, so in essence I would agree.
> 
> However with a DPDK solution it would be possible to re-use the message bus
> to pass information like device stats, application state, D-state requests
> etc. to the host and allow for management layer(e.g. OpenStack) to make
> informed decisions.

I think that management informations should be transmitted in a management
channel. Such solution should exist in OpenStack.

> Also, the scope of adding power management to qemu/KVM would be huge;
> while the easier path is not always the best and the problem of power
> management in VMs is both a DPDK problem (given that librte_power only
> worked on the host) and a general virtualization problem that would be
> better solved by those with direct knowledge of Qemu/KVM architecture
> and influence on the direction of the Qemu project.

Being a huge effort is not an argument.
Please check with Qemu community, they'll welcome it.
 
> As it stands, the host backend is simply an example application that can
> be replaced by a VMM or Orchestration layer, by using Virtio-Serial it has
> obvious leanings to Qemu, but even this could be easily swapped out for
> XenBus, IVSHMEM, IP etc.
> 
> If power management is to be eventually supported by Hypervisors directly
> then we could also enable to option to switch to that environment, currently
> the librte_power implementations (VM or Host) can be selected dynamically
> (environment auto-detection) or explicitly via rte_power_set_env(), adding
> an arbitrary number of environments is relatively easy.

Yes, you are adding a new layer to workaround hypervisor lacks. And this layer
will handle native support when it will exist. But if you implement native
support now, we don't need this extra layer.

> I hope this helps to clarify the approach.

Thanks for your explanation.

-- 
Thomas

  reply	other threads:[~2014-10-14 14:56 UTC|newest]

Thread overview: 97+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-22 18:34 [dpdk-dev] [PATCH " 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
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 [this message]
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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