Re: [dpdk-dev] [PATCH v2 1/3] cmdline: increase command line buffer

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

On Tue, Jan 12, 2016 at 02:46:07PM +0200, Panu Matilainen wrote:
> On 01/12/2016 12:49 PM, Nelio Laranjeiro wrote:
> >Allow long command lines in testpmd (like flow director with IPv6, ...).
> >
> >Signed-off-by: John McNamara <john.mcnamara@intel.com>
> >Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
> >---
> >  doc/guides/rel_notes/deprecation.rst | 5 -----
> >  lib/librte_cmdline/cmdline_rdline.h  | 2 +-
> >  2 files changed, 1 insertion(+), 6 deletions(-)
> >
> >diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> >index e94d4a2..9cb288c 100644
> >--- a/doc/guides/rel_notes/deprecation.rst
> >+++ b/doc/guides/rel_notes/deprecation.rst
> >@@ -44,8 +44,3 @@ Deprecation Notices
> >    and table action handlers will be updated:
> >    the pipeline parameter will be added, the packets mask parameter will be
> >    either removed (for input port action handler) or made input-only.
> >-
> >-* ABI changes are planned in cmdline buffer size to allow the use of long
> >-  commands (such as RETA update in testpmd).  This should impact
> >-  CMDLINE_PARSE_RESULT_BUFSIZE, STR_TOKEN_SIZE and RDLINE_BUF_SIZE.
> >-  It should be integrated in release 2.3.
> >diff --git a/lib/librte_cmdline/cmdline_rdline.h b/lib/librte_cmdline/cmdline_rdline.h
> >index b9aad9b..72e2dad 100644
> >--- a/lib/librte_cmdline/cmdline_rdline.h
> >+++ b/lib/librte_cmdline/cmdline_rdline.h
> >@@ -93,7 +93,7 @@ extern "C" {
> >  #endif
> >
> >  /* configuration */
> >-#define RDLINE_BUF_SIZE 256
> >+#define RDLINE_BUF_SIZE 512
> >  #define RDLINE_PROMPT_SIZE  32
> >  #define RDLINE_VT100_BUF_SIZE  8
> >  #define RDLINE_HISTORY_BUF_SIZE BUFSIZ
> 
> Having to break a library ABI for a change like this is a bit ridiculous.

Sure, but John McNamara needed it to handle flow director with IPv6[1].

For my part, I was needing it to manipulate the RETA table, but as I
wrote in the cover letter, it ends by breaking other commands.
Olivier Matz, has proposed another way to handle long commands lines[2],
it could be a good idea to go on this direction.

For RETA situation, we already discussed on a new API, but for now, I
do not have time for it (and as it is another ABI breakage it could only
be done for 16.07 or 2.4)[3].

If this patch is no more needed we can just drop it, for that I would
like to have the point of view from John.

> 
> I didn't try it so could be wrong, but based on a quick look, struct rdline
> could easily be made opaque to consumers by just adding functions for
> allocating and freeing it.
> 
> 	- Panu -
> 

[1] http://dpdk.org/ml/archives/dev/2015-November/027643.html
[2] http://dpdk.org/ml/archives/dev/2015-November/028557.html
[3] http://dpdk.org/ml/archives/dev/2015-October/025294.html

-- 
Nélio Laranjeiro
6WIND