xen-devel

[Top] [All Lists]

[Xen-devel] struct page_info on x86-64

from [Jan Beulich]

[Permanent Link][Original]

To:	<xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	[Xen-devel] struct page_info on x86-64
From:	"Jan Beulich" <jbeulich@xxxxxxxxxx>
Date:	Tue, 03 Apr 2007 10:13:57 +0100
Delivery-date:	Tue, 03 Apr 2007 02:11:57 -0700
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxx
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

I am getting the impression that struct page_info could (in the default case)
be reduced from 40 to 32 bytes after the 3.0.4/5 changes, which no longer
appear to require type_info and shadow_flags to be unsigned long (they
could both be unsigned int aka u32). The only hindrance then is cpumask_t
being defined as an array of longs, whereas this doesn't really need to be
64 bits wide unless NR_CPUS exceeds 32. Is it worth trying to change
cpumask_t for that purpose (improving performance of frame table
accesses as well as bumping supportable memory from approximately
1.6Tb to 2Tb)?

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

[More with this subject...]

<Prev in Thread]	Current Thread	[Next in Thread>
[Xen-devel] struct page_info on x86-64, Jan Beulich <= Re: [Xen-devel] struct page_info on x86-64, Keir Fraser

Previous by Date:	[Xen-devel] Release: VMKNOPPIX(20070328) with Trusted Boot, Kuniyasu Suzaki
Next by Date:	RE: [Xen-devel] Question regarding the number of P2M l3e entries, Ian Pratt
Previous by Thread:	[Xen-devel] Release: VMKNOPPIX(20070328) with Trusted Boot, Kuniyasu Suzaki
Next by Thread:	Re: [Xen-devel] struct page_info on x86-64, Keir Fraser
Indexes:	[Date] [Thread] [Top] [All Lists]