From mboxrd@z Thu Jan 1 00:00:00 1970 From: hxkhust Subject: About Page Cache In Xen Date: Thu, 2 Feb 2012 17:50:07 +0800 (CST) Message-ID: <1ca8a9b.1eafe.1353d7896db.Coremail.hxkhust@126.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2832872364246821424==" Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org --===============2832872364246821424== Content-Type: multipart/alternative; boundary="----=_Part_332798_1777203717.1328176207579" ------=_Part_332798_1777203717.1328176207579 Content-Type: text/plain; charset=GBK Content-Transfer-Encoding: 7bit Hi, As far as we know,due to linux filesystem,if a page cached in memroy is needed by some process,the process get it from the memory rather than the disk device.On xen platform,under most condition,we use full-virtualization VMs' virtual disk image files as templets.Thus some other full-virtualization VMs based on these templets will share the page data in the templets. Here some questions puzzled me.Is the VMM aware of the pages cached in VMs?Are VMs to be the VMM what processes to the operating system on which they are running?if a page which is cached in the VM A and come from the templet is needed by another VM B,does the VM B get it from the VM A's memory? thank you for your help. hxk ------=_Part_332798_1777203717.1328176207579 Content-Type: text/html; charset=GBK Content-Transfer-Encoding: 7bit
Hi,
 
As far as we know,due to linux filesystem,if a page cached in memroy is needed by some process,the process get it from the memory rather than the disk device.On xen platform,under most condition,we use full-virtualization VMs' virtual disk image files as  templets.Thus some other full-virtualization VMs based on these templets  will share the page data in the templets.
Here some questions puzzled me.Is the VMM aware of the pages cached in VMs?Are VMs to be the VMM what processes to the operating system on which they are running?if a page which is cached in the VM A and come from the templet is needed by another VM B,does the VM B get it from the VM A's memory?
thank you for your help.
 
hxk  


------=_Part_332798_1777203717.1328176207579-- --===============2832872364246821424== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel --===============2832872364246821424==--