[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] How much memory does a domain REALLY use...

  • To: "Graham, Simon" <Simon.Graham@xxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
  • From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
  • Date: Sat, 24 Feb 2007 19:38:05 +0000
  • Delivery-date: Sat, 24 Feb 2007 11:37:28 -0800
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>
  • Thread-index: AcdXsilmiwy4S98FTPqiaqV0JXsxkgAQHcfAAAqZ8FAAAHkC6QAJotZwAADmbD8AABQMIAAAewF1
  • Thread-topic: [Xen-devel] How much memory does a domain REALLY use...

On 24/2/07 19:26, "Graham, Simon" <Simon.Graham@xxxxxxxxxxx> wrote:

>> Yes, there's an overhead of 7MB per 1GB on i386, and 12MB per 1GB on
>> x86/64.
> What is the overhead for and where would I find it allocated?

24 bytes per 'struct page_info' and 4 bytes per machine_to_phys array entry.
The former is allocated at start-of-day near the top of arch/x86/mm.c. The
array of page_info structs is pointed at by 'frame_table'.

The overheads on x86/64 are 40 bytes per 'struct page_info' and 8 bytes per
machine_to_phys array entry.

 -- Keir

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.