Re: poll: allow f_op->poll to sleep, take #3

[Ingo Molnar <mingo@elte.hu>]

* Tejun Heo <htejun@gmail.com> wrote:

> Ingo Molnar wrote:
> > _sync() is not something that should normally be done from poll 
> > handlers. But ->poll() handlers should all be TASK_INTERRUPTIBLE, 
> > right? So wake_up_process_interruptible() should be the thing you 
> > need?
> > 
> > Anyway, if you really want to pass in a state filter, you can use the 
> > already existing wake_up_state() method as well.
> 
> It's not really about what I want but more about how the interface 
> looks in the first place.  Something like the following is simply 
> ugly.
> 
> int my_callback(param a, param b, param c)
> {
> 	WARN_ON(b != B);
> 	do_something(a);
> }
> 
> And @sync might be useful depending on who's waking it up, so we 
> either need to change the wake interface or give it an easier way to 
> pass those parameters as received.  The callback function isn't the 
> right place to ignore those parameters.  It simply doesn't know why 
> the caller is passing them in or what they mean under the 
> circumstances.

We'll likely eliminate the 'sync' parameter from the scheduler. It's 
not a flag that should be proliferated.

	Ingo