From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Subject: Re: [RFC PATCH 0/1] eventtimer: introduce event timer
 wheel
Date: Tue, 29 Aug 2017 21:37:06 +0530
Message-ID: <20170829160705.GA14529@jerin>
References: <20170817161104.24293-1-jerin.jacob@caviumnetworks.com>
 <31351930.ptpEdNRZ9E@xps> <20170829154128.GB13020@jerin>
 <17506826.eAYivCQaQA@xps>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: "Carrillo, Erik G" <erik.g.carrillo@intel.com>, dev@dpdk.org,
 "Richardson, Bruce" <bruce.richardson@intel.com>,
 "Van Haaren, Harry" <harry.van.haaren@intel.com>,
 "hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
 "Eads, Gage" <gage.eads@intel.com>,
 "nipun.gupta@nxp.com" <nipun.gupta@nxp.com>,
 "Vangati, Narender" <narender.vangati@intel.com>,
 "Rao, Nikhil" <nikhil.rao@intel.com>,
 "pbhagavatula@caviumnetworks.com" <pbhagavatula@caviumnetworks.com>,
 "jianbo.liu@linaro.org" <jianbo.liu@linaro.org>,
 "rsanford@akamai.com" <rsanford@akamai.com>
To: Thomas Monjalon <thomas@monjalon.net>
Return-path: <dev-bounces@dpdk.org>
Received: from NAM01-BY2-obe.outbound.protection.outlook.com
 (mail-by2nam01on0061.outbound.protection.outlook.com [104.47.34.61])
 by dpdk.org (Postfix) with ESMTP id 317A5325C
 for <dev@dpdk.org>; Tue, 29 Aug 2017 18:07:36 +0200 (CEST)
Content-Disposition: inline
In-Reply-To: <17506826.eAYivCQaQA@xps>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

-----Original Message-----
> Date: Tue, 29 Aug 2017 17:48:58 +0200
> From: Thomas Monjalon <thomas@monjalon.net>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> Cc: "Carrillo, Erik G" <erik.g.carrillo@intel.com>, dev@dpdk.org,
>  "Richardson, Bruce" <bruce.richardson@intel.com>, "Van Haaren, Harry"
>  <harry.van.haaren@intel.com>, "hemant.agrawal@nxp.com"
>  <hemant.agrawal@nxp.com>, "Eads, Gage" <gage.eads@intel.com>,
>  "nipun.gupta@nxp.com" <nipun.gupta@nxp.com>, "Vangati, Narender"
>  <narender.vangati@intel.com>, "Rao, Nikhil" <nikhil.rao@intel.com>,
>  "pbhagavatula@caviumnetworks.com" <pbhagavatula@caviumnetworks.com>,
>  "jianbo.liu@linaro.org" <jianbo.liu@linaro.org>, "rsanford@akamai.com"
>  <rsanford@akamai.com>
> Subject: Re: [dpdk-dev] [RFC PATCH 0/1] eventtimer: introduce event timer
>  wheel
> 
> 29/08/2017 17:41, Jerin Jacob:
> > From: Thomas Monjalon <thomas@monjalon.net>
> > > 25/08/2017 12:25, Jerin Jacob:
> > > > From: "Carrillo, Erik G" <erik.g.carrillo@intel.com>
> > > [...]
> > > > > In summary, it looks like our solutions align fairly well, and I propose that we take on the software implementation if there are no objections.
> > > > 
> > > > Sure, no objection.
> > > 
> > > Good to see such a basic function generalized for NPU and CPU.
> > > 
> > > Are you going to use rte_timer for CPU implementation?
> > > Does it mean that event_timer supersedes rte_timer?
> > 
> > IMO, we don't need to supersedes the rte_timer. The eventdev or event_timer is
> > an optional component. It is application decision to use poll mode vs event
> > driver model or combination of two.
> 
> Trying to make clear when using poll mode or event model,
> regarding CPU/NPU differences:
> If using poll mode + rte_timer, we cannot leverage NPU offloads.

Yes.

> If using event model, is it as much efficient for generic CPU?

It is case by case. I think, ATOMIC queues and PARALLEL queues can be
effectively implemented for the generic CPU. ORDERED queue(the reordering
business) may not very effective. So it is boiled down to application
requirements.