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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: kvm-ppc@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests
Date: Tue, 10 Oct 2017 19:42:14 +1000	[thread overview]
Message-ID: <20171010194140.5aec88d9@roar.ozlabs.ibm.com> (raw)
In-Reply-To: <20171010071109.31207-1-npiggin@gmail.com>

On Tue, 10 Oct 2017 17:11:09 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:

> For shared processor guests (e.g., KVM), add an idle polling mode rather
> than immediately returning to the hypervisor when the guest CPU goes
> idle.
> 
> Test setup is a 2 socket POWER9 with 4 guests running, each with vCPUs
> equal to 1/2 of real of CPUs. Saturated each guest with tbench. Using
> polling idle gives about 1.4x throughput.

Actually it's even more noticeable when the host is not over subscribed
by the looks. 2.5x-3x increase in throughput for just a single guest.

Thanks,
Nick

  reply	other threads:[~2017-10-10  9:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-10  7:11 [PATCH] powerpc/pseries/cpuidle: add polling idle for shared processor guests Nicholas Piggin
2017-10-10  9:42 ` Nicholas Piggin [this message]
2017-11-16 16:17 ` Nicholas Piggin
2018-01-22  3:34 ` Michael Ellerman

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