Re: [net-next][PATCH v2 18/18] RDS: IB: add missing connection cache usage info

From: Santosh Shilimkar
Date: Wed Dec 07 2016 - 12:20:06 EST


On 12/7/2016 9:05 AM, David Miller wrote:
From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
Date: Wed, 7 Dec 2016 08:44:04 -0800

On 12/7/2016 7:55 AM, David Miller wrote:
From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
Date: Tue, 6 Dec 2016 20:01:56 -0800

What level of compatability exists here? If we run an old tool on a
new
kernel, or a new tool on an old kernel, does it work properly?

Tools repo carries a copy of the header and thats how the old tool and
new tools have been running with older/newer kernels. There are few
more
bits left before I can start using directly kernel header for newer
tools.

Moreover this particular parameter is only used for verbose mode which
isn't used in default options.

That doesn't really answer my question, I think.

Sorry for not being clear.

Are you saying that one is required to run old tools on old kernels,
and new tools on new kernels, and that's how you have this setup in
your repo?

No.

If so, that really isn't acceptable. Both old and new tools must work
with all kernel versions.

Older version of tools works on either kernel versions. Older tools
don't parse this additional info since its copy of header not
carrying some of these extra verbose fields. Newer/Updated tools which
can parse this extra info in needs newer or an updated kernel which
supports and populates these fields.

As mentioned, this particular option used only in verbose mode so
am ok to drop this change if its still a concern.

Regards,
Santosh