Re: [RFC][PATCH 2/7] kref: Add kref_read()

From: Peter Zijlstra
Date: Thu Nov 17 2016 - 12:19:37 EST


On Thu, Nov 17, 2016 at 07:30:29AM -0500, David Windsor wrote:
> On Thu, Nov 17, 2016 at 3:34 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > No, its not a statistic. Also, I'm far from convinced stats_t is an
> > actually useful thing to have.
> >
>
> Regarding this, has there been any thought given as to how stats_t
> will meaningfully differ from atomic_t? If refcount_t is semantically
> "atomic_t with reference counter overflow protection," what
> services/guarantees does stats_t provide? I cannot think of any that
> don't require implementing overflow detection of some sort, which
> incurs a performance hit.

Afaict the whole point of stats_t was to allow overflow, since its only
stats, nobody cares etc..

I think the sole motivator is a general distaste of atomic_t, which
isn't a good reason at all.