From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Anthony Wright <anthony@overnetdata.com>
Cc: xen-devel@lists.xensource.com
Subject: Re: 5x dom0 memory increase from Xen/Linux 3.4/2.6.18 to 4.1/3.0.0
Date: Thu, 16 Jun 2011 10:56:11 -0400 [thread overview]
Message-ID: <20110616145611.GC6108@dumpdata.com> (raw)
In-Reply-To: <10979454.29.1308229105101.JavaMail.root@zimbra.overnetdata.com>
On Thu, Jun 16, 2011 at 01:58:25PM +0100, Anthony Wright wrote:
> I have a fairly old machine with 512M of RAM that I use for testing. Under Xen 3.4 with the 2.6.18 linux kernel it would happily work with dom0_mem=50M, leaving 450M for VMs. I am in the process of upgrading to Xen 4.1 with a stock 3.0.0-rc3 linux kernel (with konrad's vga-support patch). This combination however requires dom0_mem=250M to work leaving only 250M for the VMs (if I try to set dom0_mem any lower I get a kernel panic early on in the kernel boot phase).
>
> This is an increase of 5x between the two versions, and I wondered if there's an explanation why. Is it possible to reduce the memory requirements, or do I have to learn to live with it.
The SWIOTLB is taking a 64MB chunk out of it. You could lower that by 'swiotlb=2048' or so.
Also make sure to compile the CONFIG_XEN_MAX_DOMAIN_MEMORY from 128GB down to say 1.
Besides that .. run with 'memblock=debug loglevel=10 initcall_debug debug' and see what other
regions memblock reserves that could be shrunk.
>
> thanks,
>
> Anthony Wright
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
next prev parent reply other threads:[~2011-06-16 14:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-16 12:58 5x dom0 memory increase from Xen/Linux 3.4/2.6.18 to 4.1/3.0.0 Anthony Wright
2011-06-16 14:56 ` Konrad Rzeszutek Wilk [this message]
2011-06-17 15:31 ` Anthony Wright
2011-06-20 12:45 ` Konrad Rzeszutek Wilk
2011-06-22 13:15 ` Anthony Wright
2011-06-22 13:32 ` Konrad Rzeszutek Wilk
2011-06-22 14:22 ` Anthony Wright
2011-06-22 14:39 ` Konrad Rzeszutek Wilk
2011-06-22 15:53 ` Anthony Wright
2011-06-23 13:02 ` Konrad Rzeszutek Wilk
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