[PATCH 06/20] drm/gem: inline drm_gem_object_handle_reference

[Rob Clark]

On Tue, Jul 23, 2013 at 8:31 AM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> On Tue, Jul 23, 2013 at 2:07 PM, Rob Clark <robdclark at gmail.com> wrote:
>> On Tue, Jul 16, 2013 at 3:11 AM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>>> Only one callsite and since ->handle_count is not a simple reference
>>> count (it can resurrect) it's imo better to be explicit about things
>>> than hide the refcount dance.
>>
>> I'm not really sure I like this one.. I guess it could be that I'm
>> just used to the handle-ref stuff, so it doesn't seem odd not-inlined.
>>  And it does seem kinda odd / unsymmetric to have an unref w/out a
>> ref.  I guess I kinda like the bikeshed's current color in this case.
>
> I generally agree but in this case a follow-up patch ("drm/gem: fix up
> flink name create race") will change obj->handle_count from an
> atomic_t to a normal int protected by the dev->object_name_lock
> spinlock. To avoid races we need to hold that spinlock over a few
> different instructions, so with the refcounting dance inlined it's
> much more obvious that that obj->handle_count is always correctly
> protected imo.

hmm, ok.. then I'll reserve judgment until I get further through the series ;-)

if you do spin another version of the series, it could be worth
mentioning this in the commit msg

BR,
-R

> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch