From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id E52632C7A for ; Thu, 12 Feb 2015 10:23:01 +0100 (CET) Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t1C9N0hV019118 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 12 Feb 2015 04:23:01 -0500 Received: from localhost.localdomain (vpn1-5-97.ams2.redhat.com [10.36.5.97]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t1C9MxNv018593; Thu, 12 Feb 2015 04:22:59 -0500 Message-ID: <54DC70F3.4020902@redhat.com> Date: Thu, 12 Feb 2015 11:22:59 +0200 From: Panu Matilainen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "Gonzalez Monroy, Sergio" , Neil Horman References: <1422544811-26385-1-git-send-email-sergio.gonzalez.monroy@intel.com> <20150129163859.GE1999@hmsreliant.think-freely.org> <91383E96CE459D47BCE92EFBF5CE73B004F43D9B@IRSMSX108.ger.corp.intel.com> <20150129194539.GG1999@hmsreliant.think-freely.org> <91383E96CE459D47BCE92EFBF5CE73B004F453D7@IRSMSX108.ger.corp.intel.com> <20150130140507.GA2664@hmsreliant.think-freely.org> <91383E96CE459D47BCE92EFBF5CE73B004F45534@IRSMSX108.ger.corp.intel.com> <20150130181249.GC2664@hmsreliant.think-freely.org> <91383E96CE459D47BCE92EFBF5CE73B004F4AB9B@IRSMSX108.ger.corp.intel.com> In-Reply-To: <91383E96CE459D47BCE92EFBF5CE73B004F4AB9B@IRSMSX108.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH 0/8] Improve build process X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 09:23:02 -0000 On 02/11/2015 01:11 PM, Gonzalez Monroy, Sergio wrote: >> From: Neil Horman [mailto:nhorman@tuxdriver.com] >> Sent: Friday, January 30, 2015 6:13 PM >> To: Gonzalez Monroy, Sergio >> Cc: Thomas Monjalon; dev@dpdk.org >> Subject: Re: [dpdk-dev] [PATCH 0/8] Improve build process >> >> On Fri, Jan 30, 2015 at 05:38:49PM +0000, Gonzalez Monroy, Sergio wrote: > > [snip] > >>> >>> So would it be reasonable to add DT_NEEDED entries to all DPDK libraries >> but EAL? >>> If I understood what you were saying right, we could enforce the >>> 'dependency' in the linker script with something like this: >>> $ cat librte_eal.so >>> INPUT( librte_eal.so.1 -lrte_mempool -lrte_malloc) We could have such >>> linker script for librte_eal.so instead of the soft link once >>> versioning is in place. >>> >> Correct. >> >>> Things that would be missing versus the proposed patch: >>> - As I have mention in previous post, ldd info for EAL library would not >> reflect >>> its dependency to other DPDK libs. >> librte_eal.so would no show those dependencies, as far as I know (though I >> haven't explicitly checked). The subordunate libraries included in the input >> line, may or may not show dependencies among themselves, depending on >> your build setup (and the use of --no-as-needed and -l when linking the >> individual .so libraries. >> >>> - I was enforcing resolving all references when building the libraries (-z >> defs), so >>> we either remove it altogether or skip eal. >> I think thats correct, yes. >> >>> - All apps would show DT_NEEDED entries for a set of DPDK libraries that >>> in most cases are required (eal, mempool, malloc, mbuf, ring VS >>> dpdk_core) >>> >> I think apps linked to libdpdk_core would have DT_NEEDED entries for >> libdpdk_core, not the subordonate libraries (though check me on that to be >> sure). >> > Just checked on this and they do link against the subordinate libraries, although > It does not really matter as we are dropping the 'core' library approach anyway. > >>> I think that the linker script approach is reasonable if we prefer to >>> go that way instead of creating a core library. >>> >> I think it would make sense from a build environment point of view, in that it >> allows library specific flags to be incorporated properly. I think the only >> downside is that the individual libraries still need to be carried around >> (though they can be ignored from an application build/run standpoint). >> You're question should probably be asked of people using COMBINED_LIBS >> currently to make sure that meets their needs, though I think it will. >> >> Neil >> > So I just realized that I was not having into account a possible scenario, where > we have an app built with static dpdk libs then loading a dso with -d option. > > In such case, because the pmd would have DT_NEEDED entries, dlopen will fail. > So to enable such scenario we would need to build PMDs without DT_NEEDED > entries. Hmm, for that to be a problem you'd need to have the PMD built against shared dpdk libs and while the application is built against static dpdk libs. I dont think that's a supportable scenario in any case. Or is there some other scenario that I'm not seeing? - Panu -