On Fri, 2007-06-22 at 01:06 -0700, Chris Wright wrote:

Current -rt is broken when compiling with CONFIG_PARAVIRT and
CONFIG_MCOUNT both enabled.  Because CONFIG_MCOUNT disables
CONFIG_REGPARM, the calling convention must once again be explicit
with fastcall.  However, this was only half-way addressed in the -rt
patch (adding fastcall back to paravirt_ops function ptr declaration but
not the actual function definitions) so the compiled kernel has caller
putting stuff in registers and callee pulling things from the stack.
Impressive how far into boot it can get despite that ;-)  Thanks to
Steven Rostedt for prodding me and starting the initial debugging.

Chris, thanks a hell of a lot for looking into this!!!

-rt doesn't do much with paravirt, but since both -rt and lguest are two
things I love to play with, it was really bothering me that they were
not getting along.

Much appreciated!

-- Steve