From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f65.google.com (mail-wr1-f65.google.com [209.85.221.65]) by dpdk.org (Postfix) with ESMTP id D78321B4F3 for ; Thu, 4 Oct 2018 17:17:08 +0200 (CEST) Received: by mail-wr1-f65.google.com with SMTP id y16so10366194wrw.3 for ; Thu, 04 Oct 2018 08:17:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=I4zJio7bOm1nv5gEJLrZ1pJIv1vqLjDdnM6XUHJUIfU=; b=0wLR/PQMaznFfsIfiDPnKM6s4Wo9E0YrzFdjFdWhpC2iKKNiKcwoiwVin+EGfbt4Yt z5+xKxc4/d5CQNuj9bm/LQBB6t9kB3ReZxPcWp0uzGD89hWMHg7C04YbhUcoioPOf0uK TNM/AMjY5dUQ24OjAhk6mU6+FeBPeIM0lD/eDgiFZ+yE/qZAr8s0US4g862zII4Pfa89 kF2AYVdGRizOeVvz/pQ//7DqotKgY3Q4K5tz1j4Nb4apM2N/8uxlBIdgGrBAgeW5bIZ3 lRHQcLGzceuFbYEYsjpjJGgQLQgHnv8Aetc8G/LYsFRE1FsE9cOgN/mN4iFrHdhwxbgV TF4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=I4zJio7bOm1nv5gEJLrZ1pJIv1vqLjDdnM6XUHJUIfU=; b=hQiCm/FSGmURlwIYXL+8dSkcRHomNLjlgPP5osJpGMRyW2RaNBfmS7xyXlX5tuzs+o xIRVkB03w1hAs/Ws30Sun+HaVvYCL0juk6FR0JrLA9kcOAAJ5hHFrDd7eckTRQdkL4DY WTombLQt4LwCdh55twG4jnqPvLEgerD+BIaE/vptZuw0LtNoxr11mxRJgv6z33Qzz9kl TxUBaqEqY7+7QjfKBskocmygbUTHj4ZmYl2WmvyCoF13AkT2GJFaKxTZnv2uJFAh7wwD uWt7yjPk3EbUIeCGuLP9QW0MT9gou553GnNgTudK6Je8olVxXFUrhU3CQwuUg0dvhRkO SUWQ== X-Gm-Message-State: ABuFfoh3k2FJYf9sYOGYKPL4xjATbv11fexmZSZ2R5ermEyuPWyZ5KzW WgKSrvkctHn+mXpyv+lfKMis+Q== X-Google-Smtp-Source: ACcGV61OoJCyTW2LP12aJAivJSUGsn9nLtreaS2TotL253OZWS0fM6qwvGv2EGu1SMJoxflpE+60IQ== X-Received: by 2002:adf:8bc5:: with SMTP id w5-v6mr5511052wra.110.1538666228292; Thu, 04 Oct 2018 08:17:08 -0700 (PDT) Received: from bidouze.vm.6wind.com (host.78.145.23.62.rev.coltfrance.com. [62.23.145.78]) by smtp.gmail.com with ESMTPSA id h2-v6sm4798277wrs.34.2018.10.04.08.17.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Oct 2018 08:17:07 -0700 (PDT) Date: Thu, 4 Oct 2018 17:16:49 +0200 From: =?iso-8859-1?Q?Ga=EBtan?= Rivet To: "Van Haaren, Harry" Cc: "Laatz, Kevin" , "dev@dpdk.org" , "stephen@networkplumber.org" , "shreyansh.jain@nxp.com" , "thomas@monjalon.net" , "Richardson, Bruce" Message-ID: <20181004151649.m7rdybbclurufqdp@bidouze.vm.6wind.com> References: <1535026093-101872-1-git-send-email-ciara.power@intel.com> <20181003173612.67101-1-kevin.laatz@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-dev] [PATCH v2 00/10] introduce telemetry library 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: , X-List-Received-Date: Thu, 04 Oct 2018 15:17:09 -0000 Hi Harry, On Thu, Oct 04, 2018 at 01:25:51PM +0000, Van Haaren, Harry wrote: > > -----Original Message----- > > From: Van Haaren, Harry > > Sent: Thursday, October 4, 2018 2:00 PM > > To: Laatz, Kevin ; dev@dpdk.org > > Cc: stephen@networkplumber.org; gaetan.rivet@6wind.com; > > shreyansh.jain@nxp.com; thomas@monjalon.net; Richardson, Bruce > > > > Subject: RE: [PATCH v2 00/10] introduce telemetry library > > > > > -----Original Message----- > > > From: Laatz, Kevin > > > Sent: Wednesday, October 3, 2018 6:36 PM > > > To: dev@dpdk.org > > > Cc: Van Haaren, Harry ; > > > stephen@networkplumber.org; gaetan.rivet@6wind.com; > > shreyansh.jain@nxp.com; > > > thomas@monjalon.net; Laatz, Kevin > > > Subject: [PATCH v2 00/10] introduce telemetry library > > > > > > This patchset introduces a Telemetry library for DPDK Service Assurance. > > > This library provides an easy way to query DPDK Ethdev metrics. > > > > > > > > > Note: We are aware that the --telemetry flag is not working for meson > > > builds, we are working on it for a future patch. Despite opterr being set > > > to 0, --telemetry said to be 'unrecognized' as a startup print. This is a > > > cosmetic issue and will also be addressed. > > > > > > --- > > > v2: > > > - Reworked telemetry as part of EAL instead of using vdev (Gaetan) > > > - Refactored rte_telemetry_command (Gaetan) > > > - Added MAINTAINERS file entry (Stephen) > > > - Updated docs to reflect vdev to eal rework > > > - Removed collectd patch from patchset (Thomas) > > > - General code clean up from v1 feedback > > > > > > Hi Gaetan, Thomas, Stephen and Shreyansh! > > > > > > goto TL_DR; // if time is short :) > > > > > > In this v2 patchset, we've reworked the Telemetry to no longer use the vdev > > infrastructure, instead having EAL enable it directly. This was requested as > > feedback to the v1 patchset. I'll detail the approach below, and highlight > > some issues we identified while implementing it. > > > > Currently, EAL does not depend on any "DPDK" libraries (ignore kvargs etc > > for a minute). > > Telemetry is a DPDK library, so it depends on EAL. In order to have EAL > > initialize > > Telemetry, it must depend on it - this causes a circular dependency. > > > > This patchset resolves that circular dependency by using a "weak" symbol for > > telemetry init, and then the "strong" version of telemetry init will replace > > it when the library is compiled in. > > Correction: we attempted this approach - but ended up adding a TAILQ of library > initializers functions to EAL, which was then iterated during rte_eal_init(). > This also resolved the circular-dependency, but the same linking issue as > described below still exists. > > So - the same question still stands - what is the best solution for 18.11? > > > > Although this *technically* works, it > > requires > > that applications *LINK* against Telemetry library explicitly - as EAL won't > > pull > > in the Telemetry .so automatically... This means application-level build- > > system > > changes to enable --telemetry on the DPDK EAL command line. > > > > Given the complexity in enabling EAL to handle the Telemetry init() and its > > dependencies, I'd like to ask you folks for input on how to better solve > > this? > > I think the v2 is better. I have suggested a few changes, but I think you almost have a final version. Is it not possible to use -d or to put the .so in the solib_dir? If you have symbols to solve at link-time, then you have already modified you app anyway (doesn't concern rte_telemetry, but for general lib consideration). If not, you can ask EAL to load it dynamically, so it should be ok? Sorry, none of our clients are using DPDK in shared mode, I'm not familiar with the process here. But I'm convinced that libs should not subvert PMD facilities to get their way, and if something is missing it could be useful to other libraries as well, so it might as well be cleanly handled. -- Gaëtan Rivet 6WIND