From mboxrd@z Thu Jan 1 00:00:00 1970 From: Remy Horton Subject: [PATCH v3 10/10] doc: update xstats documentation Date: Mon, 30 May 2016 11:48:12 +0100 Message-ID: <1464605292-4599-11-git-send-email-remy.horton@intel.com> References: <1464605292-4599-1-git-send-email-remy.horton@intel.com> To: dev@dpdk.org Return-path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id D32D569F9 for ; Mon, 30 May 2016 12:48:26 +0200 (CEST) In-Reply-To: <1464605292-4599-1-git-send-email-remy.horton@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Signed-off-by: Remy Horton --- doc/guides/prog_guide/poll_mode_drv.rst | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/doc/guides/prog_guide/poll_mode_drv.rst b/doc/guides/prog_guide/poll_mode_drv.rst index 7698692..6cd86dd 100644 --- a/doc/guides/prog_guide/poll_mode_drv.rst +++ b/doc/guides/prog_guide/poll_mode_drv.rst @@ -299,10 +299,27 @@ Extended Statistics API ~~~~~~~~~~~~~~~~~~~~~~~ The extended statistics API allows each individual PMD to expose a unique set -of statistics. The client of the API provides an array of -``struct rte_eth_xstats`` type. Each ``struct rte_eth_xstats`` contains a -string and value pair. The amount of xstats exposed, and position of the -statistic in the array must remain constant during runtime. +of statistics. Accessing these from application programs is done via three +functions: + +* ``rte_eth_xstats_count``: Fetches the number of extended statistics. +* ``rte_eth_xstats_get``: Fills in an array of ``struct rte_eth_xstats`` + with extended statistics. +* ``rte_eth_xstats_names``: Fills in an array of ``struct rte_eth_name`` + with extended statistic name lookup information. + +Each ``struct rte_eth_xstats`` contains an identifier and value pair, and +each ``struct rte_eth_xstats_name`` contains an identifier and string pair. +Each identifier within ``struct rte_eth_xstats`` must have a corresponding +entry in ``struct rte_eth_xstats_name`` with a matching identifier. These +identifiers, as well as the number of extended statistic exposed, must +remain constant during runtime. + +Note that extended statistic identifiers are driver-specific, and hence +might not be the same for different ports. Although it is expected that +drivers will make the identifiers used within ``struct rte_eth_xstats`` and +``struct rte_eth_xstats_name`` entries match the entries' array index, this +property should not be relied on by applications for lookups. A naming scheme exists for the strings exposed to clients of the API. This is to allow scraping of the API for statistics of interest. The naming scheme uses -- 2.5.5