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 AC14AA04B1; Tue, 10 Nov 2020 14:53:12 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id AEA14F90; Tue, 10 Nov 2020 14:53:10 +0100 (CET) Received: from wout2-smtp.messagingengine.com (wout2-smtp.messagingengine.com [64.147.123.25]) by dpdk.org (Postfix) with ESMTP id 79315DED for ; Tue, 10 Nov 2020 14:53:08 +0100 (CET) Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.west.internal (Postfix) with ESMTP id 75103AA1; Tue, 10 Nov 2020 08:53:06 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Tue, 10 Nov 2020 08:53:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=fm2; bh= 4UW1VkBUEFqrdXs2xM9Y9dabv9zl/rKukOBwPDPiTtU=; b=TA3rWXON07UFEJfC wcSpAwwTMzD1MNNM9TVBk20bDit7wfHKglv7+64RLb3ezhBRhYdrdBkPtmMxQ4uL DQgADVVYvEYJ1kOkJXSftQaO2YpsBQM18D3wbe1MEhlrOziC+Qq870NBLiaUl+2c 8UIE3DQ/gOgQowprc+Uc5FOrg7cixCjn0PC1Hvp6s0bHncCjy4W0rCRg4FvJe/+w /J7jjvT4FKdB8yN/ZrszoD06hUzkz0NqMvc77S/kOHzKU3ajfATpwIlm4YVwIx8j hnTqSKjv4Hw59NRtU+NCwWPNHPCJxEkwT2BuZBOb/ucMB1Rl/6/kcsXSVSq9cHA5 9tIQ9w== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=4UW1VkBUEFqrdXs2xM9Y9dabv9zl/rKukOBwPDPiT tU=; b=PSI+2eXlPwcuDrM+vBPAnaqQ6KRDBCILWfl9EUua9ZpITI2HBvb6PJRLV XwD8fKwZYgfRZP72GqlwjLdgMnzSWMd03IggW9uBbjN/bEL1hjLsEWuZR/EmlNHz 5F9aPvch/sfnOBGZBZTQnERUNvQy3p12RfQF7FGNuJAB2tTdiXX1bGemE+Isjl4d CyECOVfyZrJFhu8oFZu1q5heZkCiLLz9clkX8y8XlpdtBGLrsgQHM2b52A6WrcCi WjMtfqPwQSWRI40KMglH0OAu2qYQtug2b/49lhQJvYpR9omW6t0pIhxhy5XpNOi3 TJQgD16RuWm2RcPGnBFjiXy28Mw9Q== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedruddujedgheejucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvufffkfgjfhgggfgtsehtufertddttddvnecuhfhrohhmpefvhhhomhgr shcuofhonhhjrghlohhnuceothhhohhmrghssehmohhnjhgrlhhonhdrnhgvtheqnecugg ftrfgrthhtvghrnhepudeggfdvfeduffdtfeeglefghfeukefgfffhueejtdetuedtjeeu ieeivdffgeehnecukfhppeejjedrudefgedrvddtfedrudekgeenucevlhhushhtvghruf hiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehthhhomhgrshesmhhonhhjrghl ohhnrdhnvght X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 34953328005A; Tue, 10 Nov 2020 08:53:05 -0500 (EST) From: Thomas Monjalon To: Bruce Richardson Cc: dev@dpdk.org, david.marchand@redhat.com Date: Tue, 10 Nov 2020 14:53:03 +0100 Message-ID: <2421980.ZJesrIL0Ng@thomas> In-Reply-To: <20201110131919.GG1641@bricha3-MOBL.ger.corp.intel.com> References: <20201027173836.891184-1-bruce.richardson@intel.com> <9843499.ZJUyaPxYeA@thomas> <20201110131919.GG1641@bricha3-MOBL.ger.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH] devtools/test-meson-builds: allow custom set of examples 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" 10/11/2020 14:19, Bruce Richardson: > On Tue, Nov 10, 2020 at 02:04:21PM +0100, Thomas Monjalon wrote: > > 10/11/2020 12:34, Bruce Richardson: > > > On Tue, Nov 10, 2020 at 12:25:13PM +0100, Thomas Monjalon wrote: > > > > 10/11/2020 11:08, Bruce Richardson: > > > > > On Mon, Nov 09, 2020 at 08:26:10PM +0100, Thomas Monjalon wrote: > > > > > > 09/11/2020 19:02, Bruce Richardson: > > > > > > > On Mon, Nov 09, 2020 at 06:09:51PM +0100, Thomas Monjalon wrote: > > > > > > > > 27/10/2020 18:38, Bruce Richardson: > > > > > > > > > To test the installation process of DPDK using "ninja install" > > > > > > > > > test-meson-builds.sh builds a subset of the examples using "make". > > > > > > > > > To allow more flexibility for people testing, allow the set of > > > > > > > > > examples chosen for this make test to be overridden using variable > > > > > > > > > "DPDK_BUILD_TEST_EXAMPLES" in the environment. > > > > > > > > > > > > > > > > > > Since a number of example apps link against drivers directly even > > > > > > > > > for shared builds, we need to ensure that LD_LIBRARY_PATH points to > > > > > > > > > the main DPDK lib folder so any dependencies of those drivers can > > > > > > > > > be found e.g. that the PCI/vdev bus driver .so is found. [All > > > > > > > > > drivers are symlinked from drivers dir back to lib dir on install, > > > > > > > > > so only one dir rather than two is needed in the path.] > > > > > > > > [...] > > > > > > > > > +libdir=$(dirname $(find $DESTDIR -name librte_eal.so)) +export > > > > > > > > > LD_LIBRARY_PATH=$libdir:$LD_LIBRARY_PATH > > > > > > > > > > > > > > > > I don't get why libdir is required for some examples, and not for > > > > > > > > others? The pkg-config file is not enough? > > > > > > > > > > > > > > > > > > > > > > It's only needed for examples that link against drivers directly. > > > > > > > > > > > > > > I believe it's needed in those cases, because app linker flags > > > > > > > (including e.g. -lrte_pmd_bond) occur before the pkg-config flags, > > > > > > > which means that the linker at that point does not have the path to > > > > > > > find the dependencies of the driver. [In a normal build, this wouldn't > > > > > > > be necessary because the library directory would be a standard path] > > > > > > > > > > > > If it's just a matter of ordering, it would be a better example to fix > > > > > > the ordering in the Makefile, isn't it? > > > > > > > > > > > > > > > > I thought about that, but it seems strange to have the DPDK linker flags > > > > > appear before the application specific flags. The general style is to have > > > > > the apps own linker flags apply first, and then the list of dependencies, > > > > > so that any app linker flags take precedence. The other option is to have > > > > > two separate LDFLAG variables for the app, one for before pkg-config flags > > > > > and the other afterwards, but that is an untidy solution. > > > > > > > > > > Therefore, I think it's better to keep the ordering in the examples as-is > > > > > and just set the library path in the script. It's only a single extra > > > > > assignment that is necessary because we are installing to a non-standard > > > > > path using DESTDIR. > > > > > > > > It is OK to add LD_LIBRARY_PATH in test-meson-builds.sh because > > > > DPDK is "installed" with a DESTDIR prefix. > > > > > > > > But this change is unrelated to test more examples, > > > > it is a general fix for examples compilation. > > > > The thing I'm missing, as I said above, > > > > "why libdir is required for some examples, and not for others?" > > > > I feel something wrong made linking work where it should not. > > > > > > > > > > As I explained above, libdir is required for examples that link directly > > > against DPDK drivers in shared builds. There are only a few examples that > > > do so, which is why the majority worked fine, and why this was not needed > > > before. > > > > Sorry I don't understand how we link other libraries without LD_LIBRARY_PATH. > > Where the library path was taken from before this change? > > > > pkg-config outputs the library path via -L flag for all the other > libraries, which is why they are picked up. Right now the flags passed are > (in the case of the bonding example app): > > LDFLAGS += -lrte_net_bond > ... > LDFLAGS_SHARED = $(shell $(PKGCONF) --libs libdpdk) > ... > build/$(APP)-shared: $(SRCS-y) Makefile $(PC_FILE) | build > $(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_SHARED) > > which resolves to (roughly): > "-lrte_net_bond -L/path/to/dpdk/libs -lrte_ethdev ..." This is the part I still don't understand. How it can resolve to path including DESTDIR? In my test, it resolves to -L/usr/local/lib so it cannot work. > This means that all the regular DPDK libs are found based off the "-L" > flag, but the rte_net_bond and its dependencies are not as they occur > before the -L flag. > > The alternative, as you suggested previously, is to move the -lrte_net_bond > to the end of the list, but that strikes me as less elegant as the LDFLAGS > for the app need to be split into two. > > A third choice is to modify the makefiles to use pkg-config "--libs-only-L" > flag to put in the relevant pkg-config path flag before the rte_net_bond. > (However, I have yet to check that all versions of pkg-config support this > flag, since we've been bitten in the past of using flags supported by only > some versions on some distros!) > > LDFLAGS += $(shell $(PKGCONF) --libs-only-L libdpdk) -lrte_net_bond > > Overall, given we are looking at a test script where we install to a > non-standard location, putting that location in the LD_LIBRARY_PATH seems > the easiest, sane solution. It also most closely matches real-world use, > where if one installs DPDK to a novel location, the path to the library > folder does need to be set somewhere for the runtime loader to find the > libs. I agree with setting LD_LIBRARY_PATH in the test script because of the "non-standard location". This is not a question.