From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alex Williams <awilliams@iweb.com>
Subject: Re: Possible regression: XEN 4.0.0 total_memory decrease
Date: Thu, 15 Apr 2010 13:42:01 -0400
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To: Keir Fraser <keir.fraser@eu.citrix.com>
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Hi,

I also want to add, my build process is practically automated. The only=20
difference I had to make for 4.0.0 was:

- Install Debian package dependencies: uuid-dev iasl gcc-multilib

Let me know if you need more information.

Thanks.


Alex Williams wrote:
> Hello,
>=20
> Both builds run a 64-bit Xen kernel and 64-bit Dom0 kernel.
>=20
> (XEN)  Xen  kernel: 64-bit, lsb, compat32
> (XEN)  Dom0 kernel: 64-bit, lsb, paddr 0xffffffff80200000 ->=20
> 0xffffffff805d388c
>=20
> As for the RAM:
>=20
> Xen 3.4.2: (XEN) System RAM: 3946MB (4041012kB)
> Xen 4.0.0: (XEN) System RAM: 4084MB (4182064kB)
>=20
> I have also verified with only 2048MB installed in the system. Here are=
=20
> the results:
>=20
> Xen 3.4.2: (XEN) System RAM: 2036MB (2084912kB)
> Xen 4.0.0: (XEN) System RAM: 1898MB (1943860kB)
>=20
> Still 150MB RAM missing... it appears this problem is static and=20
> independant of the amount of RAM installed in the system.
>=20
> Regards,
>=20
>=20
>=20
> Keir Fraser wrote:
>> Are the hypervisor and dom0 kernel 64-bit or 32-bit? Xen prints a mess=
age
>> "System RAM: xxx" early during boot. Do these differ significantly for=
=20
>> you
>> between 3.4.2 and 4.0.0?
>>
>>  K.
>>
>> On 15/04/2010 16:54, "Alex Williams" <awilliams@iweb.com> wrote:
>>
>>> Hello,
>>>
>>> I noticed a significant *decrease* (150MB) in "total_memory" on a hos=
t
>>> build using XEN 4.0.0 with kernel 2.6.18.
>>>
>>> Here are the details:
>>>
>>> Server =3D 4096MB RAM
>>> XEN 3.4.2 + kernel 2.6.18: xm info | grep total_memory =3D 4084
>>> XEN 4.0.0 + kernel 2.6.18: xm info | grep total_memory =3D 3946
>>>
>>> The exact same kernel config file was used for both builds. I also ma=
de
>>> sure there is absolutely no difference on the hosts (while the builds
>>> are created on a different machine).
>>>
>>> This seems like a regression, unless someone can provide suggestions =
on
>>> how to correct this?
>>>
>>> Thanks.
>>>
>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>>
>=20

--=20
Alexander Williams
IT Architecture Specialist
Sp=E9cialiste de l'Architecture TI
http://www.iWeb.com/