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

RE: [Xen-devel] Seamlessly sharing identical memory pages among domains


  • To: "Ian Pratt" <Ian.Pratt@xxxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxxxx>
  • From: "Scheer, Roque" <roque.scheer@xxxxxx>
  • Date: Fri, 21 May 2004 08:56:04 -0300
  • Cc: "ROQUE SCHEER (Scheer, Roque)" <roque.scheer@xxxxxx>
  • Delivery-date: Fri, 21 May 2004 12:59:10 +0100
  • List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
  • Thread-index: AcQ+0XshQuNW7Hp1ROquEuTBvOjOCwAVzMqw
  • Thread-topic: [Xen-devel] Seamlessly sharing identical memory pages among domains

>> I'm not convinced there's that much sharing to be had between
>> VMs

In the paper Carl Waldspurger reports some worthwhile sharing under
certain real world workloads:

           | Total| Shared   |Reclaimed   |
Guest Types|  MB  | MB |  %  | MB  |   %  |
-----------+------+----+-----+-----+------+
A)10 WinNT | 2048 | 880| 42.9| 673 | 32.9 |
B) 9 Linux | 1846 | 539| 29.2| 345 | 18.7 |
C) 5 Linux | 1658 | 165| 10.0| 120 | 7.2  |

>> Doing a proper shared cache is slightly trickier given the
paravirtualised 
>> memory interface -- we'd have to introduce guests to a new kind of
write 
>> fault

Wouldn't it be possible for XEN to share the pages tranparently, without
the guest OSes needing to know it?

- Roque


-------------------------------------------------------
This SF.Net email is sponsored by: Oracle 10g
Get certified on the hottest thing ever to hit the market... Oracle 10g.
Take an Oracle 10g class now, and we'll give you the exam FREE.
http://ads.osdn.com/?ad_id149&alloc_id?66&op=click
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel


 


Rackspace

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