to do scheduler tracing, first pick up the sched-devel git tree:

 http://people.redhat.com/mingo/sched-devel.git/README

which also includes a scheduler tracer. Enable 
CONFIG_CONTEXT_SWITCH_TRACER=y and CONFIG_FRAME_POINTERS=y in your
.config, rebuild the kernel, boot into the new kernel and mount debugfs:

  mkdir /debug
  mount -t debugfs nodev /debug

and read /debug/tracing/README.

The following will capture a 1 second trace of whatever happens
on your box right now:

  cd /debug/tracing/
  echo sched_switch > current_tracer
  echo 1 > tracing_enabled
  sleep 1
  echo 0 > tracing_enabled
  cat trace > /tmp/trace.txt

/tmp/trace.txt will contain the trace. Send that to kernel developers :)

some extra nice trace with function backtraces can be gotten if you do:

  echo stacktrace > /debug/tracing/iter_ctrl