From: Avi Kivity <avi@qumranet.com>
To: Zhao Forrest <forrest.zhao@gmail.com>
Cc: kvm-devel@lists.sourceforge.net, Javier Guerra <javier@guerrag.com>
Subject: Re: KVM architecture docs
Date: Wed, 05 Mar 2008 07:19:02 +0200 [thread overview]
Message-ID: <47CE2D46.1030608@qumranet.com> (raw)
In-Reply-To: <ac8af0be0803042006n520c1c17x5883f55764154dd1@mail.gmail.com>
Zhao Forrest wrote:
>> - swapping allows you to overcommit memory
>>
>
> Normally swapping mechanism choose the Least Recently Used(LRU) pages
> of a process to be swapped out. When KVM uses MMU notifier in linux
> kernel to implement swapping for VM, could KVM choose LRU pages of a
> VM to swap out? If so, could you give a brief description about how
> this is implemented?
>
The Linux memory manager approximates LRU by scanning pages for the
accessed bit, which is set in the pte by the processor when a page is
accessed through that pte. mmu notifiers provide a callback for the
check, so that kvm can check the accessed bit on the shadow ptes.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
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next prev parent reply other threads:[~2008-03-05 5:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-03 15:51 KVM architecture docs Alessandro Sardo
2008-03-03 18:23 ` Avi Kivity
2008-03-04 4:12 ` Zhao Forrest
2008-03-04 8:25 ` Avi Kivity
2008-03-04 9:02 ` Zhao Forrest
2008-03-04 9:21 ` Avi Kivity
2008-03-04 14:17 ` Javier Guerra
2008-03-04 15:08 ` Avi Kivity
2008-03-05 4:06 ` Zhao Forrest
2008-03-05 5:19 ` Avi Kivity [this message]
2008-03-05 6:05 ` Zhao Forrest
2008-03-05 6:10 ` Avi Kivity
2008-03-05 6:38 ` Avi Kivity
2008-03-05 6:51 ` Zhao Forrest
2008-03-05 6:58 ` Avi Kivity
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