Re: [dpdk-dev] [PATCH 1/3] eventdev: introduce adapter flags for periodic mode

["Carrillo, Erik G" <erik.g.carrillo@intel.com>]

Hi Shijith,

> -----Original Message-----
> From: Shijith Thotton <shijith.thotton@gmail.com>
> Sent: Wednesday, March 10, 2021 3:15 AM
> To: Carrillo, Erik G <erik.g.carrillo@intel.com>
> Cc: Shijith Thotton <sthotton@marvell.com>; Pavan Nikhilesh
> <pbhagavatula@marvell.com>; Jerin Jacob <jerinj@marvell.com>;
> dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/3] eventdev: introduce adapter flags for
> periodic mode
> 
> Hi Erik,
> 
> On Tue, Mar 09, 2021 at 08:04:32PM +0000, Carrillo, Erik G wrote:
> > > A timer adapter in periodic mode can be used to arm periodic timers.
> > > This patch adds flags used to advertise capability and configure
> > > timer adapter in periodic mode. Capability flag should be set for
> > > adapters which support periodic mode.
> > >
> > > Below is a programming sequence on the usage:
> > > 	/* check for periodic mode support by reading capability. */
> > > 	rte_event_timer_adapter_caps_get(...);
> > >
> > > 	/* create adapter in periodic mode by setting periodic flag
> > > 	   (RTE_EVENT_TIMER_ADAPTER_F_PERIODIC) and resolution. */
> > > 	rte_event_timer_adapter_create_ext(...);
> >
> > It looks like periodic support is an operating mode of the adapter
> > itself, and that all timers created with a periodic adapter instance
> > will be periodic timers.
> >
> > Is it possible to instead have "periodic/single-shot" be an attribute
> > of an event timer itself, such that a single adapter instance could
> > support either type of timer?
> >
> 
> With single type of timer per adapter, application can decide to create
> multiple adapters of required type/mode and use as needed.
> 
> For an adapter to support both type of timers, driver ops implementation has
> to follow different paths based on timer type and new capability flag should
> be introduced to expose this feature. Our HW only supports single type of
> timer per adapter.
> 
> Please let me know the approach you are aligned with.

Having a single type of timer per adapter is surprising initially, in my opinion,
but I think it does make using periodic timers simple.  Unless there are any
other comments to the contrary, I think we can proceed with this approach.

I'll respond in a separate post with comments on the patches.

Thanks,
Erik

> 
> Thanks,
> Shijith