Re: [dpdk-dev] [PATCH v2] SDK: Add scripts to initialize DPDK runtime

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

On Mon, Dec 19, 2016 at 4:15 PM, Thomas Monjalon <thomas.monjalon@6wind.com>
wrote:

> Thanks for sending your Debian/Ubuntu work.
>
> 2016-12-13 16:47, Luca Boccassi:
> > From: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> >
> > A tools/init directory is added with dpdk-init, a script that can be
> > used to initialize a DPDK runtime environment. 2 config files with
> > default options, dpdk.conf and interfaces, are provided as well
> > together with a SysV init script and a systemd service unit.
>
> I have 2 concerns:
>
> - What does exactly mean "initialize a DPDK runtime environment"?
> Should it be documented somewhere?
>

Sorry for the late reply, Luca made me aware that this was lost in the
Christmas hole.
It means that you make a system config ready to be used in a persistent way
e.g. cross reboots.

The common steps to prep a system in that regard are assigning a set of
cards to dpdk (=>dpdk-devbind) and furthermore to set up hugepages as
needed.
The latter is only a simple helper for the convenience of the admin. It can
suit 95% of the cases but if someone has something very specific in mind a
manual hugepage setup might be needed.

The conf files themself have comment on their usage.
I'm not sure how much more (on top of the comments in the config files) a
doc might be useful.
But then that might just be because I happen to know about that stuff.
We could hapilly copy the bit we have about it at
https://help.ubuntu.com/16.04/serverguide/DPDK.html#dpdk-config-dev
https://help.ubuntu.com/16.04/serverguide/DPDK.html#dpdk-config-hp

Luca/Thomas - what do you think about that?


> - Is it deprecating dpdk-setup.sh?
>

dpdk-setup is a one-shot effort and provides very different things.
the init script is for the system lifecycle, to be controlled by config
files and invoked automatically.

ATM - we covered what is needed on a regular base in the script, while
dpdk-setup has a longer list of use-cases.
If anybody identifies functions of dpdk-setup which would be reasonable in
a lifecycle management we should be open to take patches moving those from
the one-shot to the system service.
Also one could think of sharing some code between them - like providing
sourcable shell fragment that both scripts use to execute - yet I don't
think it is needed until I see a reasonable call that this is needed or
helpful.
Once (I don't expect that) all functionality would have moved it would be
deprecated, but not for now in my Opinion.

-- 
Christian Ehrhardt
Software Engineer, Ubuntu Server
Canonical Ltd