Re: Query about might_sleep()

[doug lkml <doug.lkml@gmail.com>]

Steven,

> In -rt, we convert all spin_locks() into rt_mutex() which means they
> might sleep on contention. We do not convert raw_spin_locks(), they
> stay the same both in mainline and -rt.
>
> The following is OK:
>
>   rt_mutex()
>     __might_sleep()
>     some_function()
>       local_irq_save()
>       local_irq_restore()
>
> Indention show what calls what.
>
> But if you have:
>
>   local_irq_save()
>   some_function();
>     rt_mutex();
>   local_irq_restore();
>
> Now the above *is* a bug.
>
> Is that what you are asking?
>

I think I quoted my example incorrectly.

I put it across as a stack trace, rather than the way you've put it across.
Here's what I had in mind,

local_irq_save();
  some_function();
      rt_spin_lock() --> this calls __might_sleep
local_irq_restore(); --> In this case there's a bug right?


- Doug