> -----Original Message----- > From: Eads, Gage > Sent: Wednesday, January 25, 2017 4:32 PM > To: Jerin Jacob <jerin.ja...@caviumnetworks.com>; dev@dpdk.org > Cc: thomas.monja...@6wind.com; Richardson, Bruce > <bruce.richard...@intel.com>; hemant.agra...@nxp.com; Van Haaren, Harry > <harry.van.haa...@intel.com>; McDaniel, Timothy > <timothy.mcdan...@intel.com> > Subject: RE: [dpdk-dev] [PATCH v4 1/6] eventdev: introduce event driven > programming model > > Hi Jerin, > > See the bottom of this email for a proposed tweak to the > rte_event_enqueue_burst() return value. > > > -----Original Message----- > > From: Jerin Jacob [mailto:jerin.ja...@caviumnetworks.com] > > Sent: Wednesday, December 21, 2016 3:25 AM > > To: dev@dpdk.org > > Cc: thomas.monja...@6wind.com; Richardson, Bruce > > <bruce.richard...@intel.com>; hemant.agra...@nxp.com; Eads, Gage > > <gage.e...@intel.com>; Van Haaren, Harry <harry.van.haa...@intel.com>; > > Jerin Jacob <jerin.ja...@caviumnetworks.com> > > Subject: [dpdk-dev] [PATCH v4 1/6] eventdev: introduce event driven > > programming model > > <message truncated for brevity> > > +/** > > + * Enqueue a burst of events objects or an event object supplied in > > *rte_event* > > + * structure on an event device designated by its *dev_id* through > > the event + * port specified by *port_id*. Each event object > > specifies the event queue on + * which it will be enqueued. > > + * > > + * The *nb_events* parameter is the number of event objects to > > enqueue which are + * supplied in the *ev* array of *rte_event* > > structure. > > + * > > + * The rte_event_enqueue_burst() function returns the number of + * > > events objects it actually enqueued. A return value equal to > > *nb_events* + * means that all event objects have been enqueued. > > + * > > + * @param dev_id > > + * The identifier of the device. > > + * @param port_id > > + * The identifier of the event port. > > + * @param ev > > + * Points to an array of *nb_events* objects of type *rte_event* > structure > > + * which contain the event object enqueue operations to be > processed. > > + * @param nb_events > > + * The number of event objects to enqueue, typically number of > > + * rte_event_port_enqueue_depth() available for this port. > > + * > > + * @return > > + * The number of event objects actually enqueued on the event > device. The > > + * return value can be less than the value of the *nb_events* > parameter > > when > > + * the event devices queue is full or if invalid parameters are > specified in a > > + * *rte_event*. If return value is less than *nb_events*, the > remaining events > > + * at the end of ev[] are not consumed,and the caller has to take > care of > > them > > + * > > + * @see rte_event_port_enqueue_depth() + */ +uint16_t > > +rte_event_enqueue_burst(uint8_t dev_id, uint8_t port_id, > > + const struct rte_event ev[], uint16_t nb_events); > > There are a number of reasons this operation could fail to enqueue all the > events, including: > - Backpressure > - Invalid port ID > - Invalid queue ID > - Invalid sched type when a queue is configured for ATOMIC_ONLY, > ORDERED_ONLY, or PARALLEL_ONLY > - ... > > The current API doesn't provide a straightforward way to determine the > cause of a failure. This is a particular issue on event PMDs that can > backpressure, where the app may want to treat that case differently than > the other failure cases. > > Could we change the return type to int16_t, and define a set of error > cases (e.g. -ENOSPC for backpressure, -EINVAL for an invalid argument)? > (With corresponding changes needed in the PMD API) Similarly we could > change rte_event_dequeue_burst() to return an int16_t, with -EINVAL as a > possible error case.
Use rte_errno instead, I suggest. That's what it's there for. /Bruce
