From: Avi Kivity <avi@redhat.com>
To: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Cc: jan.kiszka@siemens.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, x86@kernel.org,
yrl.pp-manager.tt@hitachi.com
Subject: Re: [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests
Date: Fri, 29 Jun 2012 17:56:47 +0300 [thread overview]
Message-ID: <4FEDC22F.9070406@redhat.com> (raw)
In-Reply-To: <4FED7495.30707@hitachi.com>
On 06/29/2012 12:25 PM, Tomoki Sekiyama wrote:
> Hi, thanks for your comments.
>
> On 2012/06/29 2:34, Avi Kivity wrote:
> > On 06/28/2012 08:26 PM, Jan Kiszka wrote:
> >>> This is both impressive and scary. What is the target scenario here?
> >>> Partitioning? I don't see this working for generic consolidation.
> >>
> >> From my POV, partitioning - including hard realtime partitions - would
> >> provide some use cases. But, as far as I saw, there are still major
> >> restrictions in this approach, e.g. that you can't return to userspace
> >> on the slave core. Or even execute the in-kernel device models on that core.
>
> Exactly this is for partitioning that requires bare-metal performance
> with low latency and realtime.
It's hard for me to evaluate how large that segment is. Since the
patchset is so intrusive, it needs a large potential user set to
justify, or a large reduction in complexity, or both.
> I think it is also useful for workload
> like HPC with MPI, that is CPU intensive and that needs low latency.
I keep hearing about people virtualizing these types of workloads, but I
haven't yet understood why.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2012-06-29 14:56 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-28 6:07 [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 01/18] x86: Split memory hotplug function from cpu_up() as cpu_memory_up() Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 02/18] x86: Add a facility to use offlined CPUs as slave CPUs Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 03/18] x86: Support hrtimer on " Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 04/18] KVM: Replace local_irq_disable/enable with local_irq_save/restore Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 05/18] KVM: Enable/Disable virtualization on slave CPUs are activated/dying Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 06/18] KVM: Add facility to run guests on slave CPUs Tomoki Sekiyama
2012-06-28 17:02 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 6:07 ` [RFC PATCH 07/18] KVM: handle page faults occured in slave CPUs on online CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 08/18] KVM: Add KVM_GET_SLAVE_CPU and KVM_SET_SLAVE_CPU to vCPU ioctl Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 09/18] KVM: Go back to online CPU on VM exit by external interrupt Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 10/18] KVM: proxy slab operations for slave CPUs on online CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 11/18] KVM: no exiting from guest when slave CPU halted Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 12/18] x86/apic: Enable external interrupt routing to slave CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 13/18] x86/apic: IRQ vector remapping on slave for " Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 14/18] KVM: Directly handle interrupts by guests without VM EXIT on " Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 15/18] KVM: vmx: Add definitions PIN_BASED_PREEMPTION_TIMER Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 16/18] KVM: add kvm_arch_vcpu_prevent_run to prevent VM ENTER when NMI is received Tomoki Sekiyama
2012-06-28 16:48 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 17/18] KVM: route assigned devices' MSI/MSI-X directly to guests on slave CPUs Tomoki Sekiyama
2012-06-28 6:08 ` [RFC PATCH 18/18] x86: request TLB flush to slave CPU using NMI Tomoki Sekiyama
2012-06-28 16:38 ` Avi Kivity
2012-06-29 9:26 ` Tomoki Sekiyama
2012-06-28 16:58 ` [RFC PATCH 00/18] KVM: x86: CPU isolation and direct interrupts handling by guests Avi Kivity
2012-06-28 17:26 ` Jan Kiszka
2012-06-28 17:34 ` Avi Kivity
2012-06-29 9:25 ` Tomoki Sekiyama
2012-06-29 14:56 ` Avi Kivity [this message]
2012-07-06 10:33 ` Tomoki Sekiyama
2012-07-12 9:04 ` Avi Kivity
2012-07-04 9:33 ` Tomoki Sekiyama
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