Re: [dpdk-dev] [PATCH v4 2/2] mempool/ring: add support for new ring sync modes

[Thomas Monjalon <thomas@monjalon.net>]

14/07/2020 11:16, Ananyev, Konstantin:
> > 
> > 13/07/2020 17:50, Konstantin Ananyev:
> > > Two new sync modes were introduced into rte_ring:
> > > relaxed tail sync (RTS) and head/tail sync (HTS).
> > > This change provides user with ability to select these
> > > modes for ring based mempool via mempool ops API.
> > >
> > > Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > > Acked-by: Gage Eads <gage.eads@intel.com>
> > > ---
> > > --- a/doc/guides/mempool/ring.rst
> > > +++ b/doc/guides/mempool/ring.rst
> > > @@ -29,6 +29,16 @@ and can be selected via mempool ops API:
> > >    Underlying **rte_ring** operates in multi-thread producer,
> > >    single-thread consumer sync mode.
> > >
> > > +- ``ring_mt_rts``
> > > +
> > > +  For underlying **rte_ring** both producer and consumer operate in
> > > +  multi-thread Relaxed Tail Sync (RTS) mode.
> > > +
> > > +- ``ring_mt_hts``
> > > +
> > > +  For underlying **rte_ring** both producer and consumer operate in
> > > +  multi-thread Haad-Tail Sync (HTS) mode.
> > 
> > Typo Haad -> Head
> 
> Will fix.
> 
> > 
> > Please explain what these modes mean and why/when use them.
> > 
> 
> We have quite detailed explanation in ring library guide:
> https://doc.dpdk.org/guides/prog_guide/ring_lib.html
> 7.6. Producer/consumer synchronization modes
> So here, I put a link to ring library guide for those who need more details.
> I can copy&paste same text here too,
> but it probably not much point in such duplication.

Do not duplicate.
Please add a direct link to the section:
https://doc.dpdk.org/guides/prog_guide/ring_lib.html#mp-rts-mc-rts

From a user perspective, I was looking for recommendation about
which mode is preferred in which case.
Maybe few words about what is an "overcommitted systems"?