Re: [dpdk-dev] [PATCH 0/7] Register external threads as lcore

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

On Wed, Jun 10, 2020 at 08:39:30PM +0530, Jerin Jacob wrote:
> On Wed, Jun 10, 2020 at 8:15 PM David Marchand
> <david.marchand@redhat.com> wrote:
> >
> > OVS and some other applications have been hacking into DPDK internals to
> > fake EAL threads and avoid performance penalty of only having non-EAL
> > threads.
> >
> > This series proposes to add a new type of lcores and maps those external
> > threads to such lcores.
> > Those threads won't run the DPDK eal mainloop and as a consequence part of
> > the EAL threads API cannot work.
> >
> > Having new lcores appearing during the process lifetime is not expected
> > by some DPDK components. This is addressed by notifying of such lcore
> > hotplug.
> >
> > This patchset has still some more work (like refusing new lcore type in
> > incompatible EAL threads API, updating the documentation and adding unit
> > tests) but I am sending it anyway as I would like to get this in for
> > 20.08.
> 
> Cool feature.
> 

+1 for this, this is something that I think has been needed for a long
time. Thanks!

> Is mempool's lcore local cache working for external cores with this scheme?
> 
> 
> >
> > For the interested parties, I have a patch [1] against dpdk-latest OVS
> > branch that makes use of this series.
> >
> > 1: https://github.com/david-marchand/ovs/commit/dpdk-latest-external-lcores
> 
> Usage is clear from the example code,
> Looking forward to having documentation and UT for the new API
> in the next version.
> 
Yes, I think we need a doc update explaining usage. The EAL chapter of the
programmers guide needs an update [1], and I think a description in the
howto would be good also [2].

[1] https://doc.dpdk.org/guides-20.05/prog_guide/env_abstraction_layer.html
[2] https://doc.dpdk.org/guides-20.05/howto/index.html

Regards,
/Bruce