Re: [PATCH v1 2/6] ethdev: retrieve xstats by ID

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> From: Jastrzebski, MichalX K
> Sent: Thursday, April 27, 2017 3:43 PM
> To: dev@dpdk.org
> Cc: Van Haaren, Harry <harry.van.haaren@intel.com>; Jain, Deepak K <deepak.k.jain@intel.com>;
> Kozak, KubaX <kubax.kozak@intel.com>
> Subject: [PATCH v1 2/6] ethdev: retrieve xstats by ID
> 
> From: Kuba Kozak <kubax.kozak@intel.com>
> 
> Extended xstats API in ethdev library to allow grouping of stats
> logically so they can be retrieved per logical grouping  managed
> by the application.
> Added new functions rte_eth_xstats_get_names_by_id and
> rte_eth_xstats_get_by_id using additional arguments (in compare
> to rte_eth_xstats_get_names and rte_eth_xstats_get) - array of ids
> and array of values.
> 
> doc: add description for modified xstats API
> Documentation change for new extended statistics API functions.
> The old API only allows retrieval of *all* of the NIC statistics
> at once. Given this requires a MMIO read PCI transaction per statistic
> it is an inefficient way of retrieving just a few key statistics.
> Often a monitoring agent only has an interest in a few key statistics,
> and the old API forces wasting CPU time and PCIe bandwidth in retrieving
> *all* statistics; even those that the application didn't explicitly
> show an interest in.
> The new, more flexible API allow retrieval of statistics per ID.
> If a PMD wishes, it can be implemented to read just the required
> NIC registers. As a result, the monitoring application no longer wastes
> PCIe bandwidth and CPU time.
> 
> Signed-off-by: Kuba Kozak <kubax.kozak@intel.com>

Acked-by: Harry van Haaren <harry.van.haaren@intel.com>