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From: Avi Kivity <avi@redhat.com>
To: Sasha Levin <levinsasha928@gmail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>,
	mtosatti@redhat.com, gregkh@linuxfoundation.org,
	sjenning@linux.vnet.ibm.com, Konrad Wilk <konrad.wilk@oracle.com>,
	kvm@vger.kernel.org
Subject: Re: [RFC 00/10] KVM: Add TMEM host/guest support
Date: Tue, 12 Jun 2012 13:12:43 +0300	[thread overview]
Message-ID: <4FD7161B.2030605@redhat.com> (raw)
In-Reply-To: <1339442716.4999.80.camel@lappy>

On 06/11/2012 10:25 PM, Sasha Levin wrote:
> On Mon, 2012-06-11 at 20:06 +0300, Avi Kivity wrote:
>> Sorry, no, first demonstrate no performance regressions, then we can
>> talk about performance improvements. 
> 
> No performance regressions? For caching? How would that work?

A small degradation might be acceptable.  2X cpu consumption is not.

IMO "using host memory" is the problem, because it involves copies and
hypercalls.  Try giving the memory to the guest, either through the
balloon or through a pci device that exposes memory that can be
withdrawn.  That will make everything *much* faster.

> 
> Or even if you meant just the kvm-tmem interface overhead, I don't see
> how that would work.
> 

I meant the overall overhead, as seen by users.

-- 
error compiling committee.c: too many arguments to function



  parent reply	other threads:[~2012-06-12 11:09 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-06 13:07 [RFC 00/10] KVM: Add TMEM host/guest support Sasha Levin
2012-06-06 13:24 ` Avi Kivity
2012-06-08 13:20   ` Sasha Levin
2012-06-08 16:06     ` Dan Magenheimer
2012-06-11 11:17       ` Avi Kivity
2012-06-11  8:09     ` Avi Kivity
2012-06-11 10:26       ` Sasha Levin
2012-06-11 11:45         ` Avi Kivity
2012-06-11 15:44           ` Dan Magenheimer
2012-06-11 17:06             ` Avi Kivity
2012-06-11 19:25               ` Sasha Levin
2012-06-11 19:56                 ` Sasha Levin
2012-06-12 11:46                   ` Avi Kivity
2012-06-12 11:58                     ` Gleb Natapov
2012-06-12 12:01                       ` Avi Kivity
2012-06-12 10:12                 ` Avi Kivity [this message]
2012-06-12  1:18               ` Dan Magenheimer
2012-06-12 10:09                 ` Avi Kivity
2012-06-12 16:40                   ` Dan Magenheimer
2012-06-12 17:54                     ` Avi Kivity

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