From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emre Can Sezer Subject: How expensive is a VM EXIT? Date: Tue, 03 Mar 2009 10:35:15 -0500 Message-ID: <49AD4E33.7070600@ncsu.edu> References: <32832343.231441235544321617.JavaMail.coremail@bj126app95.126.com> <49A60045.8080406@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=x-gbk; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <49A60045.8080406@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Hi, I've been trying to get a ballpark number on how expensive a VM EXIT is in terms of clock cycles. I'm also interested in how slow a TLB miss is. The only reference I was able to find was 13000 cycles for VM EXIT and around several hundred cycles for a TLB miss and a complete walk of page tables. Does anyone know from the top of their head or is there a reference you can share? Thanks in advance. John