On Oct 3, 2006, at 9:18 PM, Simon Burge wrote:

> Jason Thorpe wrote:
> For simple flags type usage, what would be the overhead to check a
> flag's value if it were in a proplib dictionary instead of just being
> a bit in a int in struct proc?
>
> To pick one example from kern/kern_sig.c where we loop over all
> processes:
>
>                 PROCLIST_FOREACH(p, &allproc) {
>                         if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||  
> p == cp ||
> 			   ....
>
> What would that look like in a proplib flags world, and what extra
> overheads would be involved in checking the value?

I'm not proposing changing ALL flags to some extensible mechanism ...  
what I am suggesting is that what is needed is a way for arbitrary  
subsystems to be able to augment procs and lwps.

I suggested a dictionary (can you blame me?  it's kind of my pet  
project right now :-).  Yamamoto-san suggested a pthread_specific- 
style API.  I'm actually leaning towards the latter now, because I  
think it's more appropriate for the type of usage that's being  
suggested.

-- thorpej