On Wed, 1 Aug 2018 11:05:25 +0200
Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
> The is_special_task_state() check in __set_current_state_no_track()
> has been wrongly placed. __set_current_state_no_track() is used in RT
> while a sleeping lock is acquired. It is used at the begin of the wait
> loop with TASK_UNINTERRUPTIBLE and while leaving it and restoring the
> original state. The latter part triggers the warning.
>
> Drop the special state check. This is only used within the sleeping lock
> implementation and the assignment happens while the PI lock is held.
> While at it, drop set_current_state_no_track() because it has no users.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
> include/linux/sched.h | 8 --------
> 1 file changed, 8 deletions(-)
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index a0c1c0cae992..b20264e17b02 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -132,16 +132,9 @@ struct task_group;
>
> #define __set_current_state_no_track(state_value) \
> do { \
> - WARN_ON_ONCE(is_special_task_state(state_value));\
> current->state = (state_value); \
> } while (0)
I don't think we need to keep the do { } while with a single line. It
is now equivalent to the non-debug version of __set_current_state()
which is defined as:
#define __set_current_state(state_value) \
current->state = (state_value)
-- Steve
>
> -#define set_current_state_no_track(state_value) \
> - do { \
> - WARN_ON_ONCE(is_special_task_state(state_value));\
> - smp_store_mb(current->state, (state_value)); \
> - } while (0)
> -
> #define set_special_state(state_value) \
> do { \
> unsigned long flags; /* may shadow */ \
> @@ -196,7 +189,6 @@ struct task_group;
> smp_store_mb(current->state, (state_value))
>
> #define __set_current_state_no_track(state_value) __set_current_state(state_value)
> -#define set_current_state_no_track(state_value) set_current_state(state_value)
>
> /*
> * set_special_state() should be used for those states when the blocking task
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