Re: [dpdk-dev] [PATCH v2] eventdev: remove default queue overriding

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Tue, Mar 21, 2017 at 01:51:45PM +0530, Jerin Jacob wrote:
> On Fri, Mar 10, 2017 at 03:19:15PM +0000, Harry van Haaren wrote:
> > PMDs that only do a specific type of scheduling cannot provide
> > CFG_ALL_TYPES, so the Eventdev infrastructure should not demand
> > that every PMD supports CFG_ALL_TYPES.
> > 
> > By not overriding the default configuration of the queue as
> > suggested by the PMD, the eventdev_common unit tests can pass
> > on all PMDs, regardless of their capabilities.
> > 
> > RTE_EVENT_QUEUE_CFG_DEFAULT is no longer used by the eventdev layer
> > it can be removed now. Applications should use CFG_ALL_TYPES
> > if they require enqueue of all types a queue, or specify which
> > type of queue they require.
> > 
> > The CFG_DEFAULT value is changed to CFG_ALL_TYPES in event/skeleton,
> > to not break the compile.
> > 
> > A capability flag is added that indicates if the underlying PMD
> > supports creating queues of ALL_TYPES.
> > 
> > Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
> 
> I think It is reasonable to have this capability if SW PMD can not
> support it for performance reasons. The only downside is, In application
> side there will be changes in the fast path.I think, The reasonable
> trade-off between performance and portability to keep packet processing
> functions as common and keep the pipeline advancement logic as different
> main loop based on capability.
> 
> Two reasons why CFG_ALL_TYPES important for HW
> - Event queue is the precious resource and it is very limited and it
>   consumes power and internal resources like SRAM
> - The use case like flow based event pipelining will not have constraint
>   on which event queues it enqueues to
> 
> I think We can add this capability flag now and once we have performance
> and latency test cases for eventdev then we can check is there any scope
> for improvement in SW PMD.With that note,
> 
> Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

Applied to dpdk-next-eventdev/master. Thanks.


> 
> > 
> > ---
> > 
> > v2:
> > - added capability flag to indicate if PMD supports ALL_TYPES
> > 
> > ---
> >  drivers/event/skeleton/skeleton_eventdev.c |  2 +-
> >  lib/librte_eventdev/rte_eventdev.c         |  1 -
> >  lib/librte_eventdev/rte_eventdev.h         | 13 +++++++------
> >  3 files changed, 8 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/event/skeleton/skeleton_eventdev.c b/drivers/event/skeleton/skeleton_eventdev.c
> > index dee0faf..308e28e 100644
> > --- a/drivers/event/skeleton/skeleton_eventdev.c
> > +++ b/drivers/event/skeleton/skeleton_eventdev.c
> > @@ -196,7 +196,7 @@ skeleton_eventdev_queue_def_conf(struct rte_eventdev *dev, uint8_t queue_id,
> >  
> >  	queue_conf->nb_atomic_flows = (1ULL << 20);
> >  	queue_conf->nb_atomic_order_sequences = (1ULL << 20);
> > -	queue_conf->event_queue_cfg = RTE_EVENT_QUEUE_CFG_DEFAULT;
> > +	queue_conf->event_queue_cfg = RTE_EVENT_QUEUE_CFG_ALL_TYPES;
> >  	queue_conf->priority = RTE_EVENT_DEV_PRIORITY_NORMAL;
> >  }
> >  
> > diff --git a/lib/librte_eventdev/rte_eventdev.c b/lib/librte_eventdev/rte_eventdev.c
> > index 68bfc3b..c32a776 100644
> > --- a/lib/librte_eventdev/rte_eventdev.c
> > +++ b/lib/librte_eventdev/rte_eventdev.c
> > @@ -593,7 +593,6 @@ rte_event_queue_setup(uint8_t dev_id, uint8_t queue_id,
> >  		RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->queue_def_conf,
> >  					-ENOTSUP);
> >  		(*dev->dev_ops->queue_def_conf)(dev, queue_id, &def_conf);
> > -		def_conf.event_queue_cfg = RTE_EVENT_QUEUE_CFG_DEFAULT;
> >  		queue_conf = &def_conf;
> >  	}
> >  
> > diff --git a/lib/librte_eventdev/rte_eventdev.h b/lib/librte_eventdev/rte_eventdev.h
> > index 7073987..4c73a82 100644
> > --- a/lib/librte_eventdev/rte_eventdev.h
> > +++ b/lib/librte_eventdev/rte_eventdev.h
> > @@ -271,6 +271,13 @@ struct rte_mbuf; /* we just use mbuf pointers; no need to include rte_mbuf.h */
> >   *
> >   * @see rte_event_schedule(), rte_event_dequeue_burst()
> >   */
> > +#define RTE_EVENT_DEV_CAP_QUEUE_ALL_TYPES     (1ULL << 3)
> > +/**< Event device is capable of enqueuing events of any type to any queue.
> > + * If this capability is not set, the queue only supports events of the
> > + *  *RTE_EVENT_QUEUE_CFG_* type that it was created with.
> > + *
> > + * @see RTE_EVENT_QUEUE_CFG_* values
> > + */
> >  
> >  /* Event device priority levels */
> >  #define RTE_EVENT_DEV_PRIORITY_HIGHEST   0
> > @@ -471,12 +478,6 @@ rte_event_dev_configure(uint8_t dev_id,
> >  /* Event queue specific APIs */
> >  
> >  /* Event queue configuration bitmap flags */
> > -#define RTE_EVENT_QUEUE_CFG_DEFAULT            (0)
> > -/**< Default value of *event_queue_cfg* when rte_event_queue_setup() invoked
> > - * with queue_conf == NULL
> > - *
> > - * @see rte_event_queue_setup()
> > - */
> >  #define RTE_EVENT_QUEUE_CFG_TYPE_MASK          (3ULL << 0)
> >  /**< Mask for event queue schedule type configuration request */
> >  #define RTE_EVENT_QUEUE_CFG_ALL_TYPES          (0ULL << 0)
> > -- 
> > 2.7.4
> >