On Wed, 6 Jul 2022 12:01:19 -0700
Tom Rix <t...@redhat.com> wrote:
> On 7/5/22 5:23 PM, Nicolas Chautru wrote:
> > Locking is not explicitly required but can be valuable
> > in case the application cannot guarantee to be thread-safe,
> > or specifically is at risk of using the same queue from multiple threads.
> > This is an option for PMD to use this.
> >
> > Signed-off-by: Nicolas Chautru <nicolas.chau...@intel.com>
> > ---
> > lib/bbdev/rte_bbdev.h | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/lib/bbdev/rte_bbdev.h b/lib/bbdev/rte_bbdev.h
> > index b7ecf94..8e7ca86 100644
> > --- a/lib/bbdev/rte_bbdev.h
> > +++ b/lib/bbdev/rte_bbdev.h
> > @@ -407,6 +407,8 @@ struct rte_bbdev_queue_data {
> > struct rte_bbdev_stats queue_stats; /**< Queue statistics */
> > enum rte_bbdev_enqueue_status enqueue_status; /**< Enqueue status when
> > op is rejected */
> > bool started; /**< Queue state */
> > + rte_rwlock_t lock_enq; /**< lock protection for the Enqueue */
> > + rte_rwlock_t lock_deq; /**< lock protection for the Dequeue */
>
> No.
>
> This is a good idea but needs a use before introducing another element,
> particularly a complicated one like locking
>
> Tom
Having two locks on same cacheline will create lots of ping/pong false sharing.
Also, unless the reader is holding the lock for a significant fraction of the
time
a regular spin lock will be faster.
