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

[Luca Boccassi <lboccass@Brocade.com>]

On Thu, 2017-03-16 at 19:13 +0100, Thomas Monjalon wrote:
> 2017-01-12 15:43, Christian Ehrhardt:
> > On Mon, Dec 19, 2016 at 4:15 PM, Thomas Monjalon <thomas.monjalon@6
> > wind.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://urldefense.proofpoint.com/v2/url?u=https-3A__help.ubuntu.co
> > m_16.04_serverguide_DPDK.html-23dpdk-2Dconfig-
> > 2Ddev&d=DwICAg&c=IL_XqQWOjubgfqINi2jTzg&r=QTEM8ICX7t_SLgWP3qPWtKiwK
> > Mps487LPWQx-B9AqIc&m=X_JtVB7P0d5cTRB-
> > yJXEWkNqF9aFR2rwY3msJouYpu0&s=3sa5mS7FIMFEPWKx021Dz5ySB2uax-
> > MOf1UoGWeErwI&e= 
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__help.ubuntu.co
> > m_16.04_serverguide_DPDK.html-23dpdk-2Dconfig-
> > 2Dhp&d=DwICAg&c=IL_XqQWOjubgfqINi2jTzg&r=QTEM8ICX7t_SLgWP3qPWtKiwKM
> > ps487LPWQx-B9AqIc&m=X_JtVB7P0d5cTRB-
> > yJXEWkNqF9aFR2rwY3msJouYpu0&s=093ENfa7qUYJMU4ki9kM4yUkibUOgDbMZUcbL
> > mKsnn4&e= 
> > 
> > Luca/Thomas - what do you think about that?
> 
> I was just thinking about indicating in the Linux starting guide that
> the DPDK environment can be configured in some system files.
> 
> While I see the benefit of such configuration, I am not sure we
> should
> configure the DPDK itself. We could have several applications using
> DPDK
> with different configurations.
> Do you think you could rework it in a way it can be integrated by
> applications in their own configuration?
> 
> More opinions from users and integrators would be welcome here.

Hello Thomas,

Chatted with Christian today, and as far as we can see this script
doesn't do anything that could be application specific - it just mounts
the hugepages and rebinds the PCI devices. As far as I can see how DPDK
applications use these through EAL is a bit separate. Are we missing
something?

Thanks!

-- 
Kind regards,
Luca Boccassi