Re: [dpdk-dev] [README]:Running DPDK in a LXC-based Container

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Feb 11, 2016 at 06:26:10PM +0530, Pushpasis Sarkar wrote:
> Hi Alejandro,
> 
> Thanks for the response. I tried the --file-prefix option.. But its the
> same issue.. :( Looks like the --file-prefix option only determines the
> name of the pages to be created under /mnt/huge/.
> 
> I will try the --huge-dir option as well and see if I can do anything with
> it or not...

DPDK scans the mounted filesystems to determine the directory where hugetlbfs
is mounted, and uses that directory. If you have multiple hugetlbfs mount points
then you can use --huge-dir to select just one of them. However, that's probably
not what you want, unless you have multiple hugepage sizes (e.g. 1G and 2M) and
want one app to use one size, and the other app to use the other size.

If you use --file-prefix to specify different prefixes for the different apps,
you almost certainly also need to use "-m" or "--socket-mem" flags to limit the
amount of memory each process uses. Without that option the first app to run
will use all the hugepage memory, leaving none for the other one.

Please see also the section "Running Multiple Independent DPDK Applications"
section of the Programmer's Guide in the DPDK documentation:

http://dpdk.org/doc/guides/prog_guide/multi_proc_support.html#running-multiple-independent-dpdk-applications

Regards.
/Bruce

> 
> Thanks and Regards,
> Pushpasis
> 
> On Thu, Feb 11, 2016 at 5:34 PM, Alejandro Lucero <
> alejandro.lucero@netronome.com> wrote:
> 
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> >
> > Did you try with the --file-prefix testpmd option?
> >
> > Just use different file-prefix for each DPDK app running.
> >
> > On Thu, Feb 11, 2016 at 5:01 AM, Pushpasis Sarkar <pushpasis@gmail.com>
> > wrote:
> >
> >> Hi Krishna,
> >>
> >> Off-late I have been investigating DPDK on Linux containers.. I came
> >> across
> >> this thread and found it very helpful.. But I still find some issues when
> >> I
> >> try to run the same DPDK application simultaneously on more than one LXC
> >> containers..
> >>
> >> Even when following the example provided in this thread. I am unable to
> >> run
> >> the same application simultaneously in both host and more than one LXC
> >> containers..
> >> Is there any way to achieve the same..
> >>
> >> The basic issue I see in the DPDK design that kit assumes that it will use
> >> /mnt/huge/ file-path before using it.. making it unavailable to any other
> >> process.. Can this be changed to use the sub-directory /mnt/huge/$(uname
> >> -n)/<PID>. That way it cannot stop other process running on host/lxc from
> >> using the hugepages.. I have donot have much knowledge about how the
> >> hugepage filesystem works.. so pardon my ignorance... :)
> >>
> >> Looking forward to some help on this.
> >>
> >> Regards,
> >> -Pushpasis
> >>
> >
> >
> >