From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pattan, Reshma" Subject: Re: [RFC v3] latencystats: added new library for latency stats Date: Tue, 18 Oct 2016 10:44:43 +0000 Message-ID: <3AEA2BF9852C6F48A459DA490692831F010AF910@IRSMSX109.ger.corp.intel.com> References: <1475856608-15504-1-git-send-email-reshma.pattan@intel.com> <1476711584-25377-1-git-send-email-reshma.pattan@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable To: "dev@dpdk.org" Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 77EF637B3 for ; Tue, 18 Oct 2016 12:45:22 +0200 (CEST) In-Reply-To: <1476711584-25377-1-git-send-email-reshma.pattan@intel.com> Content-Language: en-US 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" Hi, The below latency stats RFC adds new field to second cache line of mbuf. Th= is is not an ABI break. But I would like to emphasize on this point so you can have a look into th= e changes and provide comments. Thanks, Reshma > -----Original Message----- > From: Pattan, Reshma > Sent: Monday, October 17, 2016 2:40 PM > To: dev@dpdk.org > Cc: Pattan, Reshma > Subject: [RFC v3] latencystats: added new library for latency stats >=20 > Library is designed to calculate latency stats and report them to the app= lication > when queried. Library measures minimum, average, maximum latencies and > jitter in nano seconds. > Current implementation supports global latency stats, i.e. per applicatio= n stats. >=20 > Added new field to mbuf struct to mark the packet arrival time on Rx and = use the > times tamp to measure the latency on Tx. >=20 > Modified dpdk-procinfo process to display the new stats. >=20 > APIs: >=20 > Added APIs to initialize and un initialize latency stats calculation. > Added API to retrieve latency stats names and values. >=20 > Functionality: >=20 > *Library will register ethdev Rx/Tx callbacks for each active port, queue > combinations. > *Library will register latency stats names with new stats library, which = is under > design for now. > *Rx packets will be marked with time stamp on each sampling interval. > *On Tx side, packets with time stamp will be considered for calculating t= he > minimum, maximum, average latencies and jitter. > *Average latency is calculated by summing all the latencies measured for = each > time stamped packet and dividing that by total time stamped packets. > *Minimum and maximum latencies will be low and high latency values observ= ed > so far. > *Jitter calculation is done based on inter packet delay variation. > *Measured stats can be retrieved via get API of the libray (or) by callin= g generic > get API of the new stats library, in this case callback is provided to up= date the > stats into new stats library. >=20 > Signed-off-by: Reshma Pattan