Messages in this thread Patch in this message |  | | Date | Wed, 13 Nov 2013 16:45:38 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 1/1] sched: Check TASK_DEAD rather than EXIT_DEAD in schedule_debug() |
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schedule_debug() ignores in_atomic() if prev->exit_state != 0. This is not what we want, ->exit_state is set by exit_notify() but we should complain until the task does the last schedule() in TASK_DEAD.
See also 7407251a0e2e "PF_DEAD cleanup", I think this ancient commit explains why schedule() had to rely on ->exit_state, until that commit exit_notify() disabled preemption and set PF_DEAD which was used to detect the exiting task.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/sched/core.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5ac63c9..7184357 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2287,10 +2287,10 @@ static inline void schedule_debug(struct task_struct *prev) { /* * Test if we are atomic. Since do_exit() needs to call into - * schedule() atomically, we ignore that path for now. - * Otherwise, whine if we are scheduling when we should not be. + * schedule() atomically, we ignore that path. Otherwise whine + * if we are scheduling when we should not. */ - if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) + if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) __schedule_bug(prev); rcu_sleep_check(); -- 1.5.5.1
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