-----Original Message----- From: xen-...@lists.xensource.com [mailto:xen-...@lists.xensource.com] On Behalf Of xuehai zhang Sent: 28 November 2005 08:21 To: Xen Mailing List Subject: [Xen-devel] open/stat64 syscalls run faster on Xen VM than standard Linux

Dear all, When I debugged the execution performance of an application using strace, I found there are some system calls like open and stat64 which run faster on XenLinux than the standard Linux. The following is the output of running "strace -c /bin/sh -c /bin/echo foo" on both systems. An open call runs averagely 109 usec on standard Linux but only 41 usecs on XenLinux. An stat64 call runs 75 usecs on standard Linux but only 19 usecs on XenLinux. The Xen VM runs on the same physical machine as the standard Linux. It uses loopback files in dom0 as the backends of VBDs. Any insight is highly appreciated.

Thanks. Xuehai