From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: Re: [RFC] [PATCH v2] libeventdev: event driven programming model framework for DPDK Date: Fri, 28 Oct 2016 14:36:50 +0530 Message-ID: <20161028090648.GA32750@localhost.localdomain> References: <20161005072451.GA2358@localhost.localdomain> <1476214216-31982-1-git-send-email-jerin.jacob@caviumnetworks.com> <20161025174904.GA18333@localhost.localdomain> <20161026122416.GA21509@localhost.localdomain> <20161026125414.GB33288@bricha3-MOBL3.ger.corp.intel.com> <20161028030140.GA2967@localhost.localdomain> <20161028083646.GA82872@bricha3-MOBL3.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "Vangati, Narender" , "dev@dpdk.org" , "Eads, Gage" , "thomas.monjalon@6wind.com" To: Bruce Richardson Return-path: Received: from NAM01-BY2-obe.outbound.protection.outlook.com (mail-by2nam01on0064.outbound.protection.outlook.com [104.47.34.64]) by dpdk.org (Postfix) with ESMTP id D7ECA37B8 for ; Fri, 28 Oct 2016 11:07:14 +0200 (CEST) Content-Disposition: inline In-Reply-To: <20161028083646.GA82872@bricha3-MOBL3.ger.corp.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" On Fri, Oct 28, 2016 at 09:36:46AM +0100, Bruce Richardson wrote: > On Fri, Oct 28, 2016 at 08:31:41AM +0530, Jerin Jacob wrote: > > On Wed, Oct 26, 2016 at 01:54:14PM +0100, Bruce Richardson wrote: > > > On Wed, Oct 26, 2016 at 05:54:17PM +0530, Jerin Jacob wrote: > > > > On Wed, Oct 26, 2016 at 12:11:03PM +0000, Van Haaren, Harry wrote: > > > > > > -----Original Message----- > > > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jerin Jacob > > > Thanks. One other suggestion is that it might be useful to provide > > > support for having typed queues explicitly in the API. Right now, when > > > you create an queue, the queue_conf structure takes as parameters how > > > many atomic flows that are needed for the queue, or how many reorder > > > slots need to be reserved for it. This implicitly hints at the type of > > > traffic which will be sent to the queue, but I'm wondering if it's > > > better to make it explicit. There are certain optimisations that can be > > > looked at if we know that a queue only handles packets of a particular > > > type. [Not having to handle reordering when pulling events from a core > > > can be a big win for software!]. > > > > If it helps in SW implementation, then I think we can add this in queue > > configuration. > > > > > > > > How about adding: "allowed_event_types" as a field to > > > rte_event_queue_conf, with possible values: > > > * atomic > > > * ordered > > > * parallel > > > * mixed - allowing all 3 types. I think allowing 2 of three types might > > > make things too complicated. > > > > > > An open question would then be how to behave when the queue type and > > > requested event type conflict. We can either throw an error, or just > > > ignore the event type and always treat enqueued events as being of the > > > queue type. I prefer the latter, because it's faster not having to > > > error-check, and it pushes the responsibility on the app to know what > > > it's doing. > > > > How about making default as "mixed" and let application configures what > > is not required?. That way application responsibility is clear. > > something similar to ETH_TXQ_FLAGS_NOMULTSEGS, ETH_TXQ_FLAGS_NOREFCOUNT > > with default. > > > I suppose it could work, but why bother doing that? If an app knows it's > only going to use one traffic type, why not let it just state what it > will do rather than try to specify what it won't do. If mixed is needed, My thought was more inline with ethdev spec, like, ref-count is default, if application need exception then set ETH_TXQ_FLAGS_NOREFCOUNT. But it is OK, if you need other way. > then it's easy enough to specify - and we can make it the zero/default > value too. OK. Then we will make MIX as zero/default and add "allowed_event_types" in event queue config. /Jerin > > Our software implementation for now, only supports one type per queue - > which we suspect should meet a lot of use-cases. We'll have to see about > adding in mixed types in future. > > /Bruce