Re: Elimination of klists

[James Bottomley <James.Bottomley@SteelEye.com>]

On Sun, 2005-09-11 at 15:25 -0700, Andrew Morton wrote:
> James Bottomley <James.Bottomley@SteelEye.com> wrote:
> >
> > Actually, the concept of a klist is quite nice, and the beauty is that
> >  all the locking is internal to them, so users can't actually get it
> >  wrong (I like interfaces like this).
> 
> You're a bit screwed if you want to use them from interrupts..

Yes, but then they're for refcounted lists.  Quite a few of our
refcounted structures aren't safe for final put from interrupt either.
I take the implied point about wanting to leave the lock selection up to
the list head provider... I just can't see an elegant way of
implementing it given how tightly klist iterators have to bind to the
locking and refcounting.  We could always add another pair of
list_head_lock() list_head_unlock() functions which it's up to the
list_head provider also to supply ... I'm just surprised I didn't get
hammered for using that nasty OO concept of delegates with the get/put
functions ... I'm sure someone will notice if I do it a second time.

James


James