Users of the XenLinux 2.6 kernel should disable Thread Local Storage
(TLS) (e.g. by doing a mv /lib/tls /lib/tls.disabled) before
attempting to boot a XenLinux kernel2.4. You can
always reenable TLS by restoring the directory to its original location
(i.e. mv /lib/tls.disabled /lib/tls).
The reason for this is that the current TLS implementation uses
segmentation in a way that is not permissible under Xen. If TLS is not
disabled, an emulation mode is used within Xen which reduces performance
substantially. To ensure full performance you should install a
`Xen-friendly' (nosegneg) version of the library.
