From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id E46B5A0679 for ; Fri, 5 Apr 2019 17:36:06 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 701B31B547; Fri, 5 Apr 2019 17:36:05 +0200 (CEST) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id 1872C1B53E for ; Fri, 5 Apr 2019 17:36:02 +0200 (CEST) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Apr 2019 08:36:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,313,1549958400"; d="scan'208";a="161760490" Received: from bricha3-mobl.ger.corp.intel.com ([10.237.221.35]) by fmsmga001.fm.intel.com with SMTP; 05 Apr 2019 08:35:57 -0700 Received: by (sSMTP sendmail emulation); Fri, 05 Apr 2019 16:35:56 +0100 Date: Fri, 5 Apr 2019 16:35:56 +0100 From: Bruce Richardson To: Ferruh Yigit Cc: Ye Xiaolong , dev@dpdk.org, Stephen Hemminger , Luca Boccassi , Qi Zhang , Karlsson Magnus , Topel Bjorn , Maxime Coquelin , Ananyev Konstantin , David Marchand , Andrew Rybchenko , Olivier Matz Message-ID: <20190405153556.GC1710@bricha3-MOBL.ger.corp.intel.com> References: <20190301080947.91086-1-xiaolong.ye@intel.com> <20190404085113.16732-1-xiaolong.ye@intel.com> <20190404085113.16732-2-xiaolong.ye@intel.com> <20190405150525.GA41807@intel.com> <20190405152327.GB1710@bricha3-MOBL.ger.corp.intel.com> <8ac8f88f-d5d4-8543-1f0f-b73f1122f4b1@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <8ac8f88f-d5d4-8543-1f0f-b73f1122f4b1@intel.com> User-Agent: Mutt/1.11.4 (2019-03-13) Subject: Re: [dpdk-dev] [PATCH v11 1/1] net/af_xdp: introduce AF XDP PMD driver 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" Message-ID: <20190405153556.7STdKU99FgGjsmYQixiQ5whE7PHd4TQE3QxpHx-_wqE@z> On Fri, Apr 05, 2019 at 04:31:16PM +0100, Ferruh Yigit wrote: > On 4/5/2019 4:23 PM, Bruce Richardson wrote: > > On Fri, Apr 05, 2019 at 11:05:25PM +0800, Ye Xiaolong wrote: > >> Hi, Ferruh > >> > >> On 04/05, Ferruh Yigit wrote: > >>> On 4/4/2019 9:51 AM, Xiaolong Ye wrote: > >>>> Add a new PMD driver for AF_XDP which is a proposed faster version of > >>>> AF_PACKET interface in Linux. More info about AF_XDP, please refer to [1] > >>>> [2]. > >>>> > >>>> This is the vanilla version PMD which just uses a raw buffer registered as > >>>> the umem. > >>>> > >>>> [1] https://fosdem.org/2018/schedule/event/af_xdp/ > >>>> [2] https://lwn.net/Articles/745934/ > >>>> > >>>> Signed-off-by: Xiaolong Ye > >>> > >>> <...> > >>> > >>>> diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build > >>>> new file mode 100644 > >>>> index 000000000..840c93728 > >>>> --- /dev/null > >>>> +++ b/drivers/net/af_xdp/meson.build > >>>> @@ -0,0 +1,19 @@ > >>>> +# SPDX-License-Identifier: BSD-3-Clause > >>>> +# Copyright(c) 2019 Intel Corporation > >>>> + > >>>> +if host_machine.system() == 'linux' > >>>> + bpf_dep = dependency('libbpf', required: false) > >>>> + if bpf_dep.found() > >>>> + build = true > >>>> + else > >>>> + bpf_dep = cc.find_library('bpf', required: false) > >>>> + if bpf_dep.found() and cc.has_header('bpf/xsk.h', dependencies: bpf_dep) and cc.has_header('linux/if_xdp.h') > >>>> + build = true > >>>> + pkgconfig_extra_libs += '-lbpf' > >>>> + else > >>>> + build = false > >>>> + endif > >>>> + endif > >>>> + ext_deps += bpf_dep > >>>> +endif > >>>> +sources = files('rte_eth_af_xdp.c') > >>> > >>> if system is not 'linux', by default build will be 'true', right, so will it try > >>> to build the driver in that case? > >>> What about setting "build = false" before the linux check, so won't need to set > >>> it false again in the if block, only set it true if dependencies found? > >> > >> This is a good catch, we do need to initialize build = false first, otherwise > >> meson/ninja would just try to build af_xdp pmd if system is not linux, which is > >> undesired. Do I need to send a separate patch for this so you can squash it into > >> af_xdp pmd patch? > >> > >>> And can 'ext_deps' go out of if block? > >> > >> If we move `ext_deps += bpf_dep` out of if block and build system is not linux, there > >> would be error "ERROR: Unknown variable "bpf_dep".", so we need either initialize > >> bpf_dep (to value like NULL?) first or keep `ext_deps += bpf_dep` inside the if > >> block, I'd prefer keep it as it is, what's you opinion? > > > > Actually, a suggestion - rather than limiting the build to linux, why not > > just limit the build to the presence of libbpf, and not bother checking the > > OS? > > If this won't cause a problem for other OS in case they have the library, I have > no objection. > Well, they shouldn't have, and we also check for the header file "linux/if_xdp.h", so I don't think an additional check for linux itself is required. Generally, I think it's better to check for the requirements of a driver directly, rather than assuming that only certain environments would ever have them. Just sent my suggested patch: http://patches.dpdk.org/patch/52357/ /Bruce