migrating proc from zone to objcache

[Jeffrey Hsu]

  >> Are there significant portions of the proc structure
  >> that can be restored to initialized state on object puts?

  > I planned to do this in a second step after getting rid of zones.

I'll all in favor of making more use of caching pre-initialized objects, so
if this is your objective, then please go ahead.  It's just that I'd convert
over to the object cache in one step.

  > I thought that even without  the pre-initialization part, objcache has
  > the advantage of pre-allocating set of objects (as zones) and is additionally
  > mp-safe (contrary to zones and, granted, as malloc()).

Well, the zone allocator is MP-safe.  It's not hard to lock up the places that
manipulate the linked-list of free items. Look for uses of the zlock field.

								Jeffrey