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From: Paolo Bonzini <pbonzini@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: riel@redhat.com, mtosatti@redhat.com, rkrcmar@redhat.com,
	jan.kiszka@siemens.com, dmatlack@google.com
Subject: Re: [PATCH] kvm: add halt_poll_ns module parameter
Date: Tue, 10 Feb 2015 08:50:47 +0100	[thread overview]
Message-ID: <54D9B857.7080500@redhat.com> (raw)
In-Reply-To: <54D92005.2060308@de.ibm.com>



On 09/02/2015 22:00, Christian Borntraeger wrote:
> I can confirm that this also helps uperf with a 1/1 byte round trip work load
> between guests on s390. And I can confirm the higher CPU load. This is normally
> a no-go for the typical s390 users, which utilize their systems as much as 
> possible. Your check for single_task_running could actually solve that
> problem because on overcommitment this will never switch to polling if the
> runqueues get full.
> Since this is also runtime configurable and defaults to 0 it should be pretty
> painless.
> 
> The only question is: is there a sane way of doing autotuning?

The answer is: we'll see. :)  I have some ideas, I have to run them
through the necessary experiments.

Paolo

      reply	other threads:[~2015-02-10  7:50 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-06 12:48 [PATCH] kvm: add halt_poll_ns module parameter Paolo Bonzini
2015-02-09  8:22 ` Xiao Guangrong
2015-02-09  9:06   ` Paolo Bonzini
2015-02-09 10:12     ` Xiao Guangrong
2015-02-09 15:21 ` Radim Krčmář
2015-02-09 16:10   ` Paolo Bonzini
2015-02-09 17:28     ` Radim Krčmář
2015-02-09 19:52 ` David Matlack
2015-02-09 21:00 ` Christian Borntraeger
2015-02-10  7:50   ` Paolo Bonzini [this message]

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