[PATCH] introduce TASK_DEAD state
I am not sure about this patch, I am asking Ingo to take a decision.
task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion
it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should
live only in ->exit_state as documented in sched.h.
Note that this state is not visible to user-space, get_task_state() masks off
unsuitable states.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index 9dd5f13..2e4c13c 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -955,7 +955,7 @@
preempt_disable();
/* causes final put_task_struct in finish_task_switch(). */
- tsk->state = EXIT_DEAD;
+ tsk->state = TASK_DEAD;
schedule();
BUG();
diff --git a/kernel/sched.c b/kernel/sched.c
index a9405d7..74f169a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1761,10 +1761,10 @@
/*
* A task struct has one reference for the use as "current".
- * If a task dies, then it sets EXIT_DEAD in tsk->state and calls
+ * If a task dies, then it sets TASK_DEAD in tsk->state and calls
* schedule one last time. The schedule call will never return, and
* the scheduled task must drop that reference.
- * The test for EXIT_DEAD must occur while the runqueue locks are
+ * The test for TASK_DEAD must occur while the runqueue locks are
* still held, otherwise prev could be scheduled on another cpu, die
* there before we look at prev->state, and then the reference would
* be dropped twice.
@@ -1775,7 +1775,7 @@
finish_lock_switch(rq, prev);
if (mm)
mmdrop(mm);
- if (unlikely(prev_state == EXIT_DEAD)) {
+ if (unlikely(prev_state == TASK_DEAD)) {
/*
* Remove function-return probe instances associated with this
* task and put them back on the free list.
@@ -5153,7 +5153,7 @@
BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD);
/* Cannot have done final schedule yet: would have vanished. */
- BUG_ON(p->state == EXIT_DEAD);
+ BUG_ON(p->state == TASK_DEAD);
get_task_struct(p);
