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

[Van Haaren, Harry]

> -----Original Message-----
> From: Jerin Jacob [mailto:jerin.jacob at caviumnetworks.com]
> Sent: Sunday, February 19, 2017 12:32 PM
> To: Van Haaren, Harry <harry.van.haaren at intel.com>
> Cc: dev at dpdk.org; Richardson, Bruce <bruce.richardson at 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?


> Other than above comments, Its looks very good.

Thanks for review!