From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Subject: Re: [PATCH v2 3/4] net/mlx: version rdma-core glue libraries Date: Mon, 5 Feb 2018 12:37:34 -0200 Message-ID: <20180205143734.GG27676@localhost.localdomain> References: <20180202144736.8239-1-adrien.mazarguil@6wind.com> <20180205125806.GE27676@localhost.localdomain> <20180205134446.GG4256@6wind.com> <1992025.8JADqR79Gx@xps> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Adrien Mazarguil , "Van Haaren, Harry" , "dev@dpdk.org" , Shahaf Shuler , Nelio Laranjeiro To: Thomas Monjalon Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 3AC3A1B38D for ; Mon, 5 Feb 2018 15:37:37 +0100 (CET) Content-Disposition: inline In-Reply-To: <1992025.8JADqR79Gx@xps> 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 Mon, Feb 05, 2018 at 03:16:21PM +0100, Thomas Monjalon wrote: > 05/02/2018 14:44, Adrien Mazarguil: > > On Mon, Feb 05, 2018 at 10:58:06AM -0200, Marcelo Ricardo Leitner wrote: > > > On Mon, Feb 05, 2018 at 12:24:23PM +0000, Van Haaren, Harry wrote: > > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Marcelo Ricardo Leitner > > > > > Sent: Monday, February 5, 2018 12:14 PM > > > > > To: Adrien Mazarguil > > > > > Cc: Thomas Monjalon ; dev@dpdk.org; Shahaf Shuler > > > > > ; Nelio Laranjeiro > > > > > Subject: Re: [dpdk-dev] [PATCH v2 3/4] net/mlx: version rdma-core glue > > > > > libraries > > > > > > > > > > On Mon, Feb 05, 2018 at 12:24:02PM +0100, Adrien Mazarguil wrote: > > > > > > On Sun, Feb 04, 2018 at 03:29:38PM +0100, Thomas Monjalon wrote: > > > > > > > 02/02/2018 17:46, Adrien Mazarguil: > > > > > > > > --- a/drivers/net/mlx4/Makefile > > > > > > > > +++ b/drivers/net/mlx4/Makefile > > > > > > > > @@ -33,7 +33,9 @@ include $(RTE_SDK)/mk/rte.vars.mk > > > > > > > > > > > > > > > > # Library name. > > > > > > > > LIB = librte_pmd_mlx4.a > > > > > > > > -LIB_GLUE = librte_pmd_mlx4_glue.so > > > > > > > > +LIB_GLUE = $(LIB_GLUE_BASE).$(LIB_GLUE_VERSION) > > > > > > > > +LIB_GLUE_BASE = librte_pmd_mlx4_glue.so > > > > > > > > +LIB_GLUE_VERSION = 18.02.1 > > > > > > > > > > > > > > You should use the version number of the release, i.e. 18.02.0 > > > > > > > Ideally, you should retrieve it from rte_version.h. > > > > > > > > > > > > Keep in mind this only needs to be updated when the glue API gets > > > > > modified, > > > > > > and this "18.02.1" string may remain unmodified for subsequent DPDK > > > > > > releases, probably as long as the PMD doesn't use any new rdma-core calls. > > > > > > > > > > > > We've already backported this patch to 17.02 and 17.11, both requiring > > > > > > different sets of Verbs calls and thus a different version, hence the > > > > > added > > > > > > "18.02" as a starting point. The last digit may have to be modified > > > > > possibly > > > > > > several times between official DPDK releases while work is being done on > > > > > the > > > > > > PMD (i.e. per commit). > > > > > > > > > > > > In short it's not meant to follow DPDK's public versioning scheme. If you > > > > > > really think it should, doing so will make things more complex in the > > > > > > Makefile, which will have to parse rte_version.h. What's your opinion? > > > > > > > > > > What about appending date +%s output to it? It would be stricter and > > > > > automated. > > > > > > > > Adding current timestamp or date into a build breaks reproducibility of builds, so is > > > > generally not recommended. > > > > > > Then the sha1sum of mlx4_glue.h. > > > With this the size check I mentioned on the other patch would become > > > redundant and unnecessary. > > > > Using a strong hash algorithm to version a library/symbol, while possible, > > seems a bit overkill and results in ugliness: > > > > librte_pmd_mlx4.so.c4ca4eaf2fe975ead83453458f4f56db49e724f3 Ugh yes, but it wouldn't need to be that visible. A pointer on mlx*_glue and a define on PMD would be enough already. As in, an extended check to the versioning. > > > > Using a weak one like CRC32 for a shorter name poses a risk of > > collision. Moreover the next time someone decides to update all version > > notices or modify a comment will impact that hash. We'd need to isolate the > > symbol definition itself, ignore parameter names in function prototypes and > > only then we may get a somewhat meaningful hash describing a given ABI. That's what I meant with stricter. Yes it would catch such situations, but you tell me on how much we want to protect/restrict here. Do you see a reason for building only the dpdk/pmd side and not the glue library at a time? > > > > Given the added complexity, is there really a problem with simple version > > numbers we increment every time something gets modified? (Note this is > > already how our .map files work, they're not generated automatically) > > Our map files show the major version where a symbol was introduced. > It is simple because no symbol can be introduced in a minor version. > > > How about keeping things as is? I don't really see the need of unique filenames. The next patch is already leveraging RTE_EAL_PMD_PATH, which if versioned should be enough for this, no? > > You are using 18.02.1 while it is introduced in 18.02.0. > If you don't want to correlate the .so version number with DPDK version > number, maybe that 1, 2, 3 would be a simpler choice (less confusing). +1 Marcelo