Re: [dpdk-dev] [PATCH v3 04/17] eventdev: add APIs for extended stats

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

On Mon, Feb 20, 2017 at 12:12:35PM +0000, Van Haaren, Harry wrote:
> > -----Original Message-----
> > From: Jerin Jacob [mailto:jerin.jacob@caviumnetworks.com]
> > Sent: Sunday, February 19, 2017 12:32 PM
> > To: Van Haaren, Harry <harry.van.haaren@intel.com>
> > Cc: dev@dpdk.org; Richardson, Bruce <bruce.richardson@intel.com>
> > Subject: Re: [PATCH v3 04/17] eventdev: add APIs for extended stats
> 
> <snip>
> 
> > > +/**
> > > + * Reset the values of the xstats on the whole device.
> > > + *
> > > + * @param dev_id
> > > + *   The identifier of the device
> > > + * @return
> > > + *   - zero: successfully reset the statistics to zero
> > > + *   - negative value: -EINVAL invalid dev_id, -ENOTSUP if not supported.
> > > + */
> > > +int
> > > +rte_event_dev_xstats_reset(uint8_t dev_id);
> > 
> > I think it would be useful to selectively reset the specific counter if
> > needed.
> 
> 
> Ok - I like the simplicity of a single reset() covering the whole eventdev, so that the stats should be consistent. No objection to changing the API, as applications can do a full reset using the "partial" reset API if they require.
> 
> 
> > something like below(Just to share my thought in C code)
> > 
> > int
> > rte_event_dev_xstats_reset(uint8_t dev_id,
> > 	enum rte_event_dev_xstats_mode mode/* INT_MAX to specify all xstats on the whole device */
> > 	const unsigned int ids /* UINT_MAX to specify all the ids on the specific mode */
> 
> 	
> The other functions that take a mode require a "queue_port_id" to select the component (port number or queue id number). I'll add the parameter.
> 
> Also I don't like the INT_MAX solution, as the enum type doesn't have to be INT, it can be char or uintX_t - compiler and CFLAGS can be used to change the enum type IIRC.
> 
> The ids parameter is an array in the xstats_get() functions, allowing multiple ids to be retrieved in one call. This also allows a NULL parameter to indicate all. I think this suits better than a single int id, and UINT_MAX for all.
> 
> 
> TL;DR: I'm suggesting
> 
> int
> rte_event_dev_xstats_reset(uint8_t dev_id,
>         enum rte_event_dev_xstats_mode mode,   /* device, port or queue */
>         int16_t queue_port_id,                 /* Queue or Port to reset. -1 resets all of *mode* ports or queues. */
>         const uint32_t ids[]);                 /* NULL array indicates to reset all stats */
> 
> Thoughts?


looks good to me.

> 
> 
> > Other than above comments, Its looks very good.
> 
> Thanks for review!