From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christian Borntraeger <borntraeger@de.ibm.com>
Subject: Re: [PATCH 1/3v2] kvm-s390: Implement the directed yield (diag 9c)
 hypervisor call for KVM
Date: Tue, 24 Apr 2012 18:21:03 +0200
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References: <4F96A021.4000704@de.ibm.com> <1335272114-64505-1-git-send-email-borntraeger@de.ibm.com> <4F96A55E.1050703@redhat.com> <4F96CB16.8060700@de.ibm.com> <4F96D1B2.7040901@redhat.com>
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Cc: Marcelo Tossati <mtosatti@redhat.com>,
	Carsten Otte <cotte@de.ibm.com>,
	Alexander Graf <agraf@suse.de>,
	Jens Freimann <jfrei@linux.vnet.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heinz Graalfs <graalfs@linux.vnet.ibm.com>,
	KVM <kvm@vger.kernel.org>, Konstantin Weitz <WEITZKON@de.ibm.com>
To: Avi Kivity <avi@redhat.com>
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On 24/04/12 18:15, Avi Kivity wrote:
>>> instead of looking like you're doing the processing for every vcpu.  The
>>> loop is just a slow lookup which might some day be replaced by a table
>>> lookup.
>>
>> Ok. We might also have a kvm_vcpu_on_spin_directed in common code,
>> Would you prefer that? 
> 
> You mean a function that takes a vcpu and tries to yield_to() it?  Or
> something else?

Or a cpu id (number). But yes, something like that.

I dont know if that will be of use for x86 (e.g. parvirtual 
ticketlocks or something like that).

Christian