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

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



> 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  |

I haven't got any figures for WinXP. The amount of sharing for
Linux instances will be very work load dependent. I'd bet that
almost all of it could be had through a shared buffer cache (from
a CoW file system).

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

Only for guests running in "shadow page table" mode, otherwise
the guest knows about real machine frame numbers.

Ian


-------------------------------------------------------
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_id=3149&alloc_id=8166&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®.