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From: raghavendra.kt@linux.vnet.ibm.com (Raghavendra K T)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] ARM: KVM: Yield CPU when vcpu executes a WFE
Date: Tue, 08 Oct 2013 20:32:59 +0530	[thread overview]
Message-ID: <52541EA3.7010403@linux.vnet.ibm.com> (raw)
In-Reply-To: <5253FDDD.6050008@arm.com>

[...]
>>> +               kvm_vcpu_on_spin(vcpu);
>>
>> Could you also enable CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT for arm and
>> check if ple handler logic helps further?
>> we would ideally get one more optimization folded into ple handler if
>> you enable that.
>
> Just gave it a go, and the results are slightly (but consistently)
> worse. Over 10 runs:
>
> Without RELAX_INTERCEPT: Average run 3.3623s
> With RELAX_INTERCEPT: Average run 3.4226s
>
> Not massive, but still noticeable. Any clue?

Is it  a 4x overcommit? Probably we would have hit the code
overhead if it were small guests.

RELAX_INTERCEPT is worth enabling for large guests with
overcommits.

  reply	other threads:[~2013-10-08 15:02 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-07 15:40 [PATCH 0/2] ARM/arm64: KVM: Yield CPU when vcpu executes a WFE Marc Zyngier
2013-10-07 15:40 ` [PATCH 1/2] ARM: " Marc Zyngier
2013-10-07 16:04   ` Alexander Graf
2013-10-07 16:16     ` Marc Zyngier
2013-10-07 16:30       ` Alexander Graf
2013-10-07 16:53         ` Gleb Natapov
2013-10-09 13:09           ` Alexander Graf
2013-10-09 13:26             ` Gleb Natapov
2013-10-09 14:18               ` Marc Zyngier
2013-10-09 14:50                 ` Anup Patel
2013-10-09 14:52                   ` Anup Patel
2013-10-09 14:59                   ` Marc Zyngier
2013-10-09 15:10                     ` Anup Patel
2013-10-09 15:17                       ` Marc Zyngier
2013-10-09 15:17                       ` Anup Patel
2013-10-07 16:55         ` Marc Zyngier
2013-10-08 11:26   ` Raghavendra KT
2013-10-08 12:43     ` Marc Zyngier
2013-10-08 15:02       ` Raghavendra K T [this message]
2013-10-08 15:06         ` Marc Zyngier
2013-10-08 15:13           ` Raghavendra K T
2013-10-08 16:09             ` Marc Zyngier
2013-10-07 15:40 ` [PATCH 2/2] arm64: " Marc Zyngier
2013-10-07 15:52   ` Bhushan Bharat-R65777
2013-10-07 16:00     ` Marc Zyngier

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