Re: [PATCH v2 1/2] cxgb4: sched: Use refcount_t for refcount

From: Chuhong Yuan
Date: Fri Aug 02 2019 - 10:27:56 EST


Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx> ä2019å8æ2æåä äå9:40åéï
>
> On Fri, Aug 2, 2019 at 4:36 AM Chuhong Yuan <hslester96@xxxxxxxxx> wrote:
> >
> > refcount_t is better for reference counters since its
> > implementation can prevent overflows.
> > So convert atomic_t ref counters to refcount_t.
> >
> > Signed-off-by: Chuhong Yuan <hslester96@xxxxxxxxx>
> > ---
> > Changes in v2:
> > - Convert refcount from 0-base to 1-base.
>
> This changes the initial value from 0 to 1, but does not change the
> release condition. So this introduces an accounting bug?

I have noticed this problem and have checked other files which use refcount_t.
I find although the refcounts are 1-based, they still use
refcount_dec_and_test()
to check whether the resource should be released.
One example is drivers/char/mspec.c.
Therefore I think this is okay and do not change the release condition.