From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 74268A00BE; Tue, 28 Apr 2020 16:45:49 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 4720F1D5F2; Tue, 28 Apr 2020 16:45:49 +0200 (CEST) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 4BB4E1D5ED for ; Tue, 28 Apr 2020 16:45:47 +0200 (CEST) IronPort-SDR: YugRCFZe5MT3rqwkzb6JIueYXwVDobhRYcXMF+ZIx0T+Q8yveE3Vzwb/YL+REacVvxwOGeRDVt Wc4WrpiBX49Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2020 07:45:46 -0700 IronPort-SDR: VXLetGuu4joYgX0/BY/t/ryIHuCRMi2RT+aFeeaKVECOYJ+v3bX1FG6TLacRiDbN5ptxQQGItC +3FvtkLeSkFA== X-IronPort-AV: E=Sophos;i="5.73,328,1583222400"; d="scan'208";a="367517011" Received: from bricha3-mobl.ger.corp.intel.com ([10.214.246.178]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 28 Apr 2020 07:45:40 -0700 Date: Tue, 28 Apr 2020 15:45:35 +0100 From: Bruce Richardson To: Ferruh Yigit Cc: Jerin Jacob , "Dumitrescu, Cristian" , Nithin Dabilpuram , "Singh, Jasvinder" , Thomas Monjalon , Andrew Rybchenko , "dev@dpdk.org" , "jerinj@marvell.com" , "kkanas@marvell.com" , Nithin Dabilpuram , "Kinsella, Ray" , Neil Horman , Luca Boccassi , Kevin Traynor , David Marchand Message-ID: <20200428144535.GC1897@bricha3-MOBL.ger.corp.intel.com> References: <20200330160019.29674-1-ndabilpuram@marvell.com> <20200422172104.23099-1-nithind1988@gmail.com> <3f14bb70-b963-437d-9451-ccee3b100915@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3f14bb70-b963-437d-9451-ccee3b100915@intel.com> Subject: Re: [dpdk-dev] [PATCH v4 1/4] ethdev: add tm support for shaper config in pkt mode X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Apr 28, 2020 at 03:06:20PM +0100, Ferruh Yigit wrote: > On 4/27/2020 5:59 PM, Jerin Jacob wrote: > > On Mon, Apr 27, 2020 at 10:19 PM Ferruh Yigit wrote: > >> > >> On 4/27/2020 5:29 PM, Jerin Jacob wrote: > >>> On Mon, Apr 27, 2020 at 9:42 PM Ferruh Yigit wrote: > >>>> > >>>> On 4/27/2020 10:19 AM, Dumitrescu, Cristian wrote: > >>>>> > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Yigit, Ferruh > >>>>>> Sent: Saturday, April 25, 2020 9:09 PM > >>>>>> To: Dumitrescu, Cristian ; Nithin Dabilpuram > >>>>>> ; Singh, Jasvinder ; > >>>>>> Thomas Monjalon ; Andrew Rybchenko > >>>>>> > >>>>>> Cc: dev@dpdk.org; jerinj@marvell.com; kkanas@marvell.com; Nithin > >>>>>> Dabilpuram > >>>>>> Subject: Re: [PATCH v4 1/4] ethdev: add tm support for shaper config in pkt > >>>>>> mode > >>>>>> > >>>>>> On 4/24/2020 11:28 AM, Dumitrescu, Cristian wrote: > >>>>>>> > >>>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: Nithin Dabilpuram > >>>>>>>> Sent: Wednesday, April 22, 2020 6:21 PM > >>>>>>>> To: Singh, Jasvinder ; Dumitrescu, Cristian > >>>>>>>> ; Thomas Monjalon > >>>>>>>> ; Yigit, Ferruh ; Andrew > >>>>>>>> Rybchenko > >>>>>>>> Cc: dev@dpdk.org; jerinj@marvell.com; kkanas@marvell.com; Nithin > >>>>>>>> Dabilpuram > >>>>>>>> Subject: [PATCH v4 1/4] ethdev: add tm support for shaper config in pkt > >>>>>>>> mode > >>>>>>>> > >>>>>>>> From: Nithin Dabilpuram > >>>>>>>> > >>>>>>>> Some NIC hardware support shaper to work in packet mode i.e > >>>>>>>> shaping or ratelimiting traffic is in packets per second (PPS) as > >>>>>>>> opposed to default bytes per second (BPS). Hence this patch > >>>>>>>> adds support to configure shared or private shaper in packet mode, > >>>>>>>> provide rate in PPS and add related tm capabilities in port/level/node > >>>>>>>> capability structures. > >>>>>>>> > >>>>>>>> This patch also updates tm port/level/node capability structures with > >>>>>>>> exiting features of scheduler wfq packet mode, scheduler wfq byte mode > >>>>>>>> and private/shared shaper byte mode. > >>>>>>>> > >>>>>>>> SoftNIC PMD is also updated with new capabilities. > >>>>>>>> > >>>>>>>> Signed-off-by: Nithin Dabilpuram > >>>>>>>> --- > >>>>>>>> v3..v4: > >>>>>>>> - Update text under packet_mode as per Cristian. > >>>>>>>> - Update rte_eth_softnic_tm.c based on Jasvinder's comments. > >>>>>>>> - Add error enum > >>>>>> RTE_TM_ERROR_TYPE_SHAPER_PROFILE_PACKET_MODE > >>>>>>>> - Fix shaper_profile_check() with packet mode check > >>>>>>>> - Fix typo's > >>>>>>>> > >>>>>>> > >>>>>>> Acked-by: Cristian Dumitrescu > >>>>>>> > >>>>>> > >>>>>> Hi Nithin, > >>>>>> > >>>>>> It looks like patch is causing ABI break, I am getting following warning [1], > >>>>>> can you please check? > >>>>>> > >>>>>> [1] > >>>>>> https://pastebin.com/XYNFg14u > >>>>> > >>>>> > >>>>> Hi Ferruh, > >>>>> > >>>>> The RTE_TM API is marked as experimental, but it looks that this was not correctly marked when __rte_experimental ABI checker was introduced. > >>>>> > >>>>> It is marked as experimental at the top of the rte_tm.h, similarly to other APIs introduced around same time, but it was not correctly picked up by the ABI check procedure when later introduced, so __rte_experimental was not added to every function. > >>>>> > >>>> > >>>> :( > >>>> > >>>> Is it time to mature them? > >>>> > >>>> As you said they are not marked as experimental both in header file (function > >>>> declarations) and .map file. > >>>> > >>>> The problem is, they are not marked as experimental in DPDK_20.0 ABI (v19.11), > >>>> so marking them as experimental now will break the ABI. Not sure what to do, > >>>> cc'ed a few ABI related names for comment. > >>>> > >>>> For me, we need to proceed as the experimental tag removed and APIs become > >>>> mature starting from v19.11, since this is what happened in practice, and remove > >>>> a few existing being experimental references in the doxygen comments. > >>> > >>> I think, accidentally we can not make a library as NON-experimental. > >>> TM never went through experimental to mature transition(see git log > >>> lib/librte_ethdev/rte_tm.h) > >>> It was a bug to not mark as experimental in each function in the ABI process. > >>> Some of the features like packet marking are not even implemented by any HW. > >>> I think, we can make API stable only all the features are implemented > >>> by one or two HW. > >> > >> Fair enough, specially if the API is not ready yet. > >> > >> But they were part of stable ABI, and marking them as experimental now will > >> break the old applications using these APIs. > > > > it is still marked as EXPERIMENTAL everywhere and API is not ready yet. > > Existing experimental marks are text only for human parsing. > > The compiler attribute and build time checks are missing, and the symbol in the > binary doesn't have experimental tag. Our scripts and automated checks won't > detect it as experimental. > > My point is just having experimental comment in header file is not enough to > qualify the APIs as experimental. > > > Anyway, we need to break the ABI to make it work on various HW. > > I am not sure what to do? > > IMO, We need to send a patch as Fixes: for the bug of not adding > > __rte_experimental in each function. > > Yes, this is where we are, both you and Cristian suggest API is not ready and > should be experimental, but they were part of stable ABI, making them > experimental will break the ABI. > It looks like there is no good option but we should select one of the bad ones. > > > > > Traffic Management API - EXPERIMENTAL > > M: Cristian Dumitrescu > > T: git://dpdk.org/next/dpdk-next-qos > > F: lib/librte_ethdev/rte_tm* > >> > >>> > >>>> > >>>> Ray, Neil, David, Luca, Kevin, what do you think? > >> While I'm not called any of those names, allow me to give my 2c. Since these are marked in binaries as part of the stable ABI, I think we need to honour that for the next two releases 20.05 and 20.08 [which means that we need to put in versioned functions for any changes, not that we can't change anything] For 20.11, I think these should then have one of two options taken: * have these "fixed" and ready to be marked as stable, and officially part of v21 ABI or * mark them as experimental properly, and look to have them as part of the v22 or subsequent ABI Given the comments here, I would tend towards the latter of the above two options, but that's really a decision for the maintainers. Remember, this is not the first bug we have encountered where we messed up some ABI versions in the 19.11 release, and, like the previous one with the screwed up version number, I think we need to honour the ABI committments made, especially since in this case it's only for a few more months till 20.11 development starts. /Bruce