From: Dor Laor <dlaor@redhat.com>
To: David Martin <dmartls1@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: KSM and HugePages
Date: Sun, 25 Oct 2009 00:13:25 +0200 [thread overview]
Message-ID: <4AE37C05.2060907@redhat.com> (raw)
In-Reply-To: <42da86010910231121i6c0e3835qca8e98cf96a181b4@mail.gmail.com>
On 10/23/2009 08:21 PM, David Martin wrote:
> Does KSM support HugePages? Reading the Fedora 12 feature list I notice this:
> "Using huge pages for guest memory does have a downside, however - you
> can no longer swap nor balloon guest memory."
> However it is unclear to me if that includes KSM.
ksm pages are only standard 4k pages.
>
> If I use 1GB HugePages and KSM (assuming this is possible), does that
> mean the entire 1GB page has to match another for them to merge? Are
> there any other downsides to using them other than swapping and
> ballooning?
It needs to be available at VM creation time.
Also the tlb size for use pages is smaller although it does bring better
results than 4k pages.
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prev parent reply other threads:[~2009-10-24 22:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-23 18:21 KSM and HugePages David Martin
2009-10-24 22:13 ` Dor Laor [this message]
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