DPDK patches and discussions
 help / color / mirror / Atom feed
From: Marcelo Ricardo Leitner <mleitner@redhat.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>,
	"Van Haaren, Harry" <harry.van.haaren@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	Shahaf Shuler <shahafs@mellanox.com>,
	Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Subject: Re: [dpdk-dev] [PATCH v2 3/4] net/mlx: version rdma-core glue libraries
Date: Mon, 5 Feb 2018 12:37:34 -0200	[thread overview]
Message-ID: <20180205143734.GG27676@localhost.localdomain> (raw)
In-Reply-To: <1992025.8JADqR79Gx@xps>

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 <adrien.mazarguil@6wind.com>
> > > > > Cc: Thomas Monjalon <thomas@monjalon.net>; dev@dpdk.org; Shahaf Shuler
> > > > > <shahafs@mellanox.com>; Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
> > > > > 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

  parent reply	other threads:[~2018-02-05 14:37 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-02 15:16 [dpdk-dev] [PATCH v1 0/4] net/mlx: enhance rdma-core glue configuration Adrien Mazarguil
2018-02-02 15:16 ` [dpdk-dev] [PATCH v1 1/4] net/mlx: add debug checks to glue structure Adrien Mazarguil
2018-02-02 15:16 ` [dpdk-dev] [PATCH v1 2/4] net/mlx: fix missing includes for rdma-core glue Adrien Mazarguil
2018-02-02 15:16 ` [dpdk-dev] [PATCH v1 3/4] net/mlx: version rdma-core glue libraries Adrien Mazarguil
2018-02-02 15:16 ` [dpdk-dev] [PATCH v1 4/4] net/mlx: make rdma-core glue path configurable Adrien Mazarguil
2018-02-02 16:46 ` [dpdk-dev] [PATCH v2 0/4] net/mlx: enhance rdma-core glue configuration Adrien Mazarguil
2018-02-02 16:46   ` [dpdk-dev] [PATCH v2 1/4] net/mlx: add debug checks to glue structure Adrien Mazarguil
2018-02-05 12:27     ` Marcelo Ricardo Leitner
2018-02-05 13:31       ` Adrien Mazarguil
2018-02-02 16:46   ` [dpdk-dev] [PATCH v2 2/4] net/mlx: fix missing includes for rdma-core glue Adrien Mazarguil
2018-02-02 16:46   ` [dpdk-dev] [PATCH v2 3/4] net/mlx: version rdma-core glue libraries Adrien Mazarguil
2018-02-04 14:29     ` Thomas Monjalon
2018-02-05 11:24       ` Adrien Mazarguil
2018-02-05 12:13         ` Marcelo Ricardo Leitner
2018-02-05 12:24           ` Van Haaren, Harry
2018-02-05 12:43             ` Marcelo Ricardo Leitner
2018-02-05 12:58             ` Marcelo Ricardo Leitner
2018-02-05 13:44               ` Adrien Mazarguil
2018-02-05 14:16                 ` Thomas Monjalon
2018-02-05 14:33                   ` Adrien Mazarguil
2018-02-05 14:37                   ` Marcelo Ricardo Leitner [this message]
2018-02-05 14:59                     ` Adrien Mazarguil
2018-02-05 15:29                       ` Marcelo Ricardo Leitner
2018-02-05 15:54                         ` Adrien Mazarguil
2018-02-05 17:06                           ` Marcelo Ricardo Leitner
2018-02-06 11:06                             ` Adrien Mazarguil
2018-02-02 16:46   ` [dpdk-dev] [PATCH v2 4/4] net/mlx: make rdma-core glue path configurable Adrien Mazarguil
2018-02-02 16:52   ` [dpdk-dev] [PATCH v2 0/4] net/mlx: enhance rdma-core glue configuration Nélio Laranjeiro
2018-02-06 11:31   ` Shahaf Shuler

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180205143734.GG27676@localhost.localdomain \
    --to=mleitner@redhat.com \
    --cc=adrien.mazarguil@6wind.com \
    --cc=dev@dpdk.org \
    --cc=harry.van.haaren@intel.com \
    --cc=nelio.laranjeiro@6wind.com \
    --cc=shahafs@mellanox.com \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).