Messages in this thread |  | | Date | Thu, 26 Apr 2018 18:02:27 +0200 | From | Andrea Parri <> | Subject | Re: [PATCH v1] kthread/smpboot: Serialize kthread parking against wakeup |
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On Thu, Apr 26, 2018 at 10:41:31AM +0200, Peter Zijlstra wrote:
[...]
> +/* > + * Special states are those that do not use the normal wait-loop pattern. See > + * the comment with set_special_state(). > + */ > +#define is_special_state(state) \ > + ((state) == TASK_DEAD || \ > + (state) == TASK_STOPPED) > + > #ifdef CONFIG_DEBUG_ATOMIC_SLEEP > > +/* > + * Assert we don't use the regular *set_current_state() helpers for special > + * states. See the comment with set_special_state(). > + */ > +#define assert_special_state(state) WARN_ON_ONCE(is_special_state(state))
Nitpicking, this name suggests "Shout if the state is NOT special" to me: maybe,
#define assert_special_state(state) WARN_ON_ONCE(!is_special_state(state)) #define assert_regular_state(state) WARN_ON_ONCE(is_special_state(state))
or just do with the WARN_ON_ONCE()s ?
Andrea
> + > #define __set_current_state(state_value) \ > do { \ > + assert_special_state(state_value); \ > current->task_state_change = _THIS_IP_; \ > current->state = (state_value); \ > } while (0) > + > #define set_current_state(state_value) \ > do { \ > + assert_special_state(state_value); \ > current->task_state_change = _THIS_IP_; \ > smp_store_mb(current->state, (state_value)); \ > } while (0) > > +#define set_special_state(state_value) \ > + do { \ > + unsigned long flags; /* may shadow */ \ > + WARN_ON_ONCE(!is_special_state(state_value)); \ > + raw_spin_lock_irqsave(¤t->pi_lock, flags); \ > + current->task_state_change = _THIS_IP_; \ > + current->state = (state_value); \ > + raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ > + } while (0)
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