Re: [PATCH 1/3] jump label: add enabled/disabled state to jump label key entries

[Jason Baron <jbaron@redhat.com>]

On Wed, Nov 24, 2010 at 09:20:09AM +0100, Peter Zijlstra wrote:
> On Tue, 2010-11-23 at 16:27 -0500, Jason Baron wrote:
> >         struct hlist_head modules;
> >         unsigned long key;
> > +       u32 nr_entries : 31,
> > +              enabled :  1;
> >  }; 
> 
> I still don't see why you do this, why not simply mandate that the key
> is of type atomic_t* and use *key as enabled state?
> 

Because I want to use *key as a pointer directly to 'struct jump_label_entry'.
In this way jump_label_enable(), jump_label_disable(), become O(1) operations.
That way we don't need any hashing.

thanks,

-Jason