[dpdk-dev] [RFC] [PATCH v2] libeventdev: event driven programming model framework for DPDK

[Eads, Gage]

>  -----Original Message-----
>  From: Jerin Jacob [mailto:jerin.jacob at caviumnetworks.com]
>  Sent: Sunday, October 16, 2016 11:18 PM
>  To: Eads, Gage <gage.eads at intel.com>
>  Cc: dev at dpdk.org; thomas.monjalon at 6wind.com; Richardson, Bruce
>  <bruce.richardson at intel.com>; Vangati, Narender
>  <narender.vangati at intel.com>; hemant.agrawal at nxp.com
>  Subject: Re: [dpdk-dev] [RFC] [PATCH v2] libeventdev: event driven
>  programming model framework for DPDK
>  
>  On Fri, Oct 14, 2016 at 03:00:57PM +0000, Eads, Gage wrote:
>  > Thanks Jerin, this looks good. I've put a few notes/questions inline.
>  
>  Thanks Gage.
>  
>  >
>  > >  +
>  > >  +/**
>  > >  + * Get the device identifier for the named event device.
>  > >  + *
>  > >  + * @param name
>  > >  + *   Event device name to select the event device identifier.
>  > >  + *
>  > >  + * @return
>  > >  + *   Returns event device identifier on success.
>  > >  + *   - <0: Failure to find named event device.
>  > >  + */
>  > >  +extern uint8_t
>  > >  +rte_event_dev_get_dev_id(const char *name);
>  >
>  > This return type should be int8_t, or some signed type, to support the failure
>  case.
>  
>  Makes sense. I will change to int to make consistent with
>  rte_cryptodev_get_dev_id()
>  
>  >
>  > >  +};
>  > >  +
>  > >  +/**
>  > >  + * Schedule one or more events in the event dev.
>  > >  + *
>  > >  + * An event dev implementation may define this is a NOOP, for
>  > > instance if  + * the event dev performs its scheduling in hardware.
>  > >  + *
>  > >  + * @param dev_id
>  > >  + *   The identifier of the device.
>  > >  + */
>  > >  +extern void
>  > >  +rte_event_schedule(uint8_t dev_id);
>  >
>  > One idea: Have the function return the number of scheduled packets (or 0 for
>  implementations that do scheduling in hardware). This could be a helpful
>  diagnostic for the software scheduler.
>  
>  How about returning an implementation specific value ?
>  Rather than defining certain function associated with returned value.
>  Just to  make sure it works with all HW/SW implementations. Something like
>  below,
>  
>  /**
>   * Schedule one or more events in the event dev.
>   *
>   * An event dev implementation may define this is a NOOP, for instance if
>   * the event dev performs its scheduling in hardware.
>   *
>   * @param dev_id
>   *   The identifier of the device.
>   * @return
>   *   Implementation specific value from the event driver for diagnostic purpose
>   */
>  extern int
>  rte_event_schedule(uint8_t dev_id);
>  
>  

That's fine by me.

I also had a comment on the return value of rte_event_dev_info_get() in my previous email: "I'm wondering if this return type should be int, so we can return an error if the dev_id is invalid."

What do you think?

Thanks,
Gage

>  
>