[dpdk-dev] [PATCH 1/2] ethdev: make flow API primary/secondary process safe

[Suanming Mou]

> -----Original Message-----
> From: Stephen Hemminger <stephen at networkplumber.org>
> Sent: Wednesday, March 17, 2021 8:14 AM
> To: Suanming Mou <suanmingm at nvidia.com>
> Cc: dev at dpdk.org
> Subject: Re: [PATCH 1/2] ethdev: make flow API primary/secondary process safe
> 
> On Tue, 16 Mar 2021 23:48:57 +0000
> Suanming Mou <suanmingm at nvidia.com> wrote:
> 
> > Hi Stephen,
> >
> > > -----Original Message-----
> > > From: Stephen Hemminger <stephen at networkplumber.org>
> > > Sent: Tuesday, March 16, 2021 3:27 AM
> > > To: dev at dpdk.org
> > > Cc: Stephen Hemminger <stephen at networkplumber.org>; Suanming Mou
> > > <suanmingm at nvidia.com>
> > > Subject: [PATCH 1/2] ethdev: make flow API primary/secondary process
> > > safe
> > >
> > > Posix mutex are not by default safe for protecting for usage from
> > > multiple processes. The flow ops mutex could be used by both primary
> > > and secondary processes.
> >
> > Process safe is something more widely scope. I assume it should be another
> feature but not a bugfix for thread-safe?
> > And the fag RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE we have added is just
> thread safe.
> >
> 
> OK, that makes sense. Is this in the documentation?

We have the description as below in doc/guides/prog_guide/rte_flow.rst:

If PMD interfaces don't support re-entrancy/multi-thread safety,
the rte_flow API functions will protect threads by mutex per port.
The application can check whether ``RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE``
is set in ``dev_flags``, meaning the PMD is thread-safe regarding rte_flow,
so the API level protection is disabled.