WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] credit2 data structures

To: "George Dunlap" <George.Dunlap@xxxxxxxxxxxxx>
Subject: [Xen-devel] credit2 data structures
From: "Jan Beulich" <JBeulich@xxxxxxxx>
Date: Thu, 13 Oct 2011 10:42:53 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 13 Oct 2011 02:43:26 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
George,

while hunting down direct assignments of cpumask_t variables (which I'm
trying to eliminate so that hypervisor binaries built for many CPUs won't
have undue memory overhead on "normal" [smaller] systems), I stumbled
across memory references that at the first glance looked buggy to me
due to their huge immediates. As it turns out, they're not buggy but a
result of credit2's struct csched_private - particularly having a NR_CPUS
sized array of struct csched_runqueue_data, which in turn has three
cpumask_t-s, totaling to a structure size of about 6.5Mb when building
for 4095 CPUs (the current upper limit in Xen).

Apart from the possibility of allocating the arrays (and maybe also the
cpumask_t-s) separately (for which I can come up with a patch on top
of what I' currently putting together) - is it really necessary to have
all these, the more that there can be multiple instances of the structure
with CPU pools?

Jan


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

<Prev in Thread] Current Thread [Next in Thread>