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From: David Vrabel <david.vrabel@citrix.com>
To: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [PATCH] x86: use 'dom0_mem' to limit the number of pages for dom0
Date: Tue, 16 Aug 2011 14:11:47 +0100	[thread overview]
Message-ID: <4E4A6C93.10008@citrix.com> (raw)
In-Reply-To: <1313499116.5010.104.camel@zakaz.uk.xensource.com>

On 16/08/11 13:51, Ian Campbell wrote:
> 
> The key difference is that classic-Xen kernels called both
> XENMEM_memory_map and XENMEM_machine_memory_map and dealt with both,
> whereas pvops (dom0) calls XENMEM_machine_memory_map and tries to figure
> out how much of the E820_RAM therein it can actually use based on
> nr_pages and such. You've used XENMEM_maximum_reservation in your
> followup series which I think is a suitable surrogate for calling
> XENMEM_memory_map (although I didn't check).

XENMEM_memory_map for dom0 doesn't work as nothing populates the map.

Classic-Xen kernels appear to invent a memory map based only on nr_pages
and it's non-obvious where it gets any other limit from (I didn't look
that hard though).

I did originally make XENMEM_memory_map work for dom0 but using
XENMEM_maximum_reservation looked more relevant.

David

  reply	other threads:[~2011-08-16 13:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-15 18:08 [PATCH] x86: use 'dom0_mem' to limit the number of pages for dom0 David Vrabel
2011-08-16  0:31 ` Konrad Rzeszutek Wilk
2011-08-16 12:29   ` David Vrabel
2011-08-16 12:51     ` Ian Campbell
2011-08-16 13:11       ` David Vrabel [this message]
2011-08-19 15:35 ` David Vrabel
2011-08-23  9:01 ` Jan Beulich
2011-08-23  9:26   ` Keir Fraser
2011-08-23  9:41     ` Jan Beulich
2011-08-23 12:03       ` Keir Fraser
2011-08-23 15:54   ` David Vrabel

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