Peter Zijlstra <pet...@infradead.org> :
> On Fri, Jan 19, 2018 at 02:11:18AM +0100, Francois Romieu wrote:
> > Peter Zijlstra <pet...@infradead.org> :
> > [...]
> > > There is only 1 variable afaict. Memory barriers need at least 2 in
> > > order to be able to do _anything_.
> >
> > I don't get your point: why don't {cur_tx, dirty_tx} qualify as said
> > two variables ?
>
> There wasn't any cur_tx in the code you provided.
/* A skbuff with nr_frags needs nr_frags+1 entries in the tx queue */
#define TX_FRAGS_READY_FOR(tp,nr_frags) \
(TX_SLOTS_AVAIL(tp) >= (nr_frags + 1))
#define TX_SLOTS_AVAIL(tp) \
(tp->dirty_tx + NUM_TX_DESC - tp->cur_tx)
Both are also used in rtl_tx.
I don't get your point. Even a single variable is scattered through
the system.
--
Ueimor
