Messages in this thread | | | Date | Tue, 30 Sep 2014 00:13:44 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 10/11] sched: Debug nested sleeps |
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On 09/24, Peter Zijlstra wrote: > > +#ifdef CONFIG_DEBUG_ATOMIC_SLEEP > + > +#define __set_task_state(tsk, state_value) \ > + do { \ > + (tsk)->task_state_change = _THIS_IP_; \ > + (tsk)->state = (state_value); \ > + } while (0)
...
> @@ -7143,6 +7143,19 @@ void __might_sleep(const char *file, int > { > static unsigned long prev_jiffy; /* ratelimiting */ > > + /* > + * Blocking primitives will set (and therefore destroy) current->state, > + * since we will exit with TASK_RUNNING make sure we enter with it, > + * otherwise we will destroy state. > + */ > + if (WARN(current->state != TASK_RUNNING, > + "do not call blocking ops when !TASK_RUNNING; " > + "state=%lx set at [<%p>] %pS\n", > + current->state, > + (void *)current->task_state_change, > + (void *)current->task_state_change)) > + __set_current_state(TASK_RUNNING);
Question: now that we have ->task_state_change, perhaps it makes sense to redefine fixup_sleep()
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP #define fixup_sleep() (current->task_state_change = 0) #else #define fixup_sleep() do { } while (0) #endif
and make the WARN() above depend on task_state_change != 0 ?
This is minor, but this way CONFIG_DEBUG_ATOMIC_SLEEP will not imply a subtle behavioural change.
Oleg.
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