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From: Marc Zyngier <maz@kernel.org>
To: Yejune Deng <yejune.deng@gmail.com>
Cc: catalin.marinas@arm.com, linux-kernel@vger.kernel.org,
	will@kernel.org, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] KVM: arm64: Add big.LITTLE architecture support for vcpu
Date: Fri, 05 Mar 2021 12:02:20 +0000	[thread overview]
Message-ID: <87h7lpzu43.wl-maz@kernel.org> (raw)
In-Reply-To: <20210305103425.73380-1-yejune.deng@gmail.com>

On Fri, 05 Mar 2021 10:34:25 +0000,
Yejune Deng <yejune.deng@gmail.com> wrote:
> 
> In big.LITTLE architecture,the application layer calls KVM_ARM_VCPU_INIT
> several times.Sometimes the thread will run on the big core, sometimes
> will run on the little core.The big core and the little core has always
> different cpuid, but the init target is fixed. and that leads to
> init->target != phys_target. So modify phys target from the current core
> to all cpu online.

This is done on purpose, and it is userspace's responsibility to pin
its vcpu threads to a certain type of CPUs if it cares at all.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Yejune Deng <yejune.deng@gmail.com>
Cc: james.morse@arm.com, julien.thierry.kdev@gmail.com,
	suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: Add big.LITTLE architecture support for vcpu
Date: Fri, 05 Mar 2021 12:02:20 +0000	[thread overview]
Message-ID: <87h7lpzu43.wl-maz@kernel.org> (raw)
In-Reply-To: <20210305103425.73380-1-yejune.deng@gmail.com>

On Fri, 05 Mar 2021 10:34:25 +0000,
Yejune Deng <yejune.deng@gmail.com> wrote:
> 
> In big.LITTLE architecture,the application layer calls KVM_ARM_VCPU_INIT
> several times.Sometimes the thread will run on the big core, sometimes
> will run on the little core.The big core and the little core has always
> different cpuid, but the init target is fixed. and that leads to
> init->target != phys_target. So modify phys target from the current core
> to all cpu online.

This is done on purpose, and it is userspace's responsibility to pin
its vcpu threads to a certain type of CPUs if it cares at all.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Yejune Deng <yejune.deng@gmail.com>
Cc: james.morse@arm.com, julien.thierry.kdev@gmail.com,
	suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: Add big.LITTLE architecture support for vcpu
Date: Fri, 05 Mar 2021 12:02:20 +0000	[thread overview]
Message-ID: <87h7lpzu43.wl-maz@kernel.org> (raw)
In-Reply-To: <20210305103425.73380-1-yejune.deng@gmail.com>

On Fri, 05 Mar 2021 10:34:25 +0000,
Yejune Deng <yejune.deng@gmail.com> wrote:
> 
> In big.LITTLE architecture,the application layer calls KVM_ARM_VCPU_INIT
> several times.Sometimes the thread will run on the big core, sometimes
> will run on the little core.The big core and the little core has always
> different cpuid, but the init target is fixed. and that leads to
> init->target != phys_target. So modify phys target from the current core
> to all cpu online.

This is done on purpose, and it is userspace's responsibility to pin
its vcpu threads to a certain type of CPUs if it cares at all.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

  reply	other threads:[~2021-03-05 12:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-05 10:34 [PATCH] KVM: arm64: Add big.LITTLE architecture support for vcpu Yejune Deng
2021-03-05 10:34 ` Yejune Deng
2021-03-05 10:34 ` Yejune Deng
2021-03-05 12:02 ` Marc Zyngier [this message]
2021-03-05 12:02   ` Marc Zyngier
2021-03-05 12:02   ` Marc Zyngier

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