This does not make a functional difference, so ignore it if you
like. Two reasons you might want it:
1) It's in 2.5.x, so you might want it for consistency.
2) Comments in sched.h refer to cpus_runnable being ~0
if the process is not running on any CPU.
diff -Nru a/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h Mon Dec 16 11:58:42 2002
+++ b/include/linux/sched.h Mon Dec 16 11:58:42 2002
@@ -482,8 +482,8 @@
policy: SCHED_OTHER, \
mm: NULL, \
active_mm: &init_mm, \
- cpus_runnable: -1, \
- cpus_allowed: -1, \
+ cpus_runnable: ~0UL, \
+ cpus_allowed: ~0UL, \
run_list: LIST_HEAD_INIT(tsk.run_list), \
next_task: &tsk, \
prev_task: &tsk, \