Hi,
On Tue, May 10, 2022 at 10:52 AM Miquel Raynal
<miquel.raynal@xxxxxxxxxxx> wrote:
>
> Hi Alex,
>
> > > --- a/net/mac802154/tx.c
> > > +++ b/net/mac802154/tx.c
> > > @@ -106,6 +106,21 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
> > > return NETDEV_TX_OK;
> > > }
> > >
> > > +void ieee802154_hold_queue(struct ieee802154_local *local)
> > > +{
> > > + atomic_inc(&local->phy->hold_txs);
> > > +}
> > > +
> > > +void ieee802154_release_queue(struct ieee802154_local *local)
> > > +{
> > > + atomic_dec(&local->phy->hold_txs);
> > > +}
> > > +
> > > +bool ieee802154_queue_is_held(struct ieee802154_local *local)
> > > +{
> > > + return atomic_read(&local->phy->hold_txs);
> > > +}
> >
> > I am not getting this, should the release_queue() function not do
> > something like:
> >
> > if (atomic_dec_and_test(hold_txs))
> > ieee802154_wake_queue(local);
> >
> > I think we don't need the test of "ieee802154_queue_is_held()" here,
> > then we need to replace all stop_queue/wake_queue with hold and
> > release?
>
> That's actually a good idea. I've implemented it and it looks nice too.
> I'll clean this up and share a new version with:
> - The wake call checked everytime hold_txs gets decremented
> - The removal of the _queue_is_held() helper
> - _wake/stop_queue() turned static
> - _hold/release_queue() used everywhere
>
I think there is also a lock necessary for atomic inc/dec hitting zero
and the stop/wake call afterwards... ,there are also a lot of
optimization techniques to only hold the lock for hitting zero cases
in such areas. However we will see...
- Alex
