Re: [PATCH] drm: Replace kref with a simple atomic reference count

On Fri, 26 Nov 2010 08:38:29 +1000, Dave Airlie airlied@redhat.com wrote:

On Thu, 2010-11-25 at 21:40 +0000, Chris Wilson wrote:

...

For a deferred-free cache of unreferenced bound objects, a simple reference count is required without the baggage of kref.

eh?

The issue with kref is that it does:

void kref_get(struct kref *kref) { WARN_ON(!atomic_read(&kref->refcount)); atomic_inc(&kref->refcount); smp_mb__after_atomic_inc(); }

which causes havoc when you are trying to keep a list of unreferenced objects. That's all I'm trying to avoid. -Chris