Re: [dpdk-dev] [PATCH v2] app/testpmd: fix testpmd flows left before port stop.

[Gregory Etelson <getelson@nvidia.com>]

Hello Andrew,

> On 11/26/20 7:43 PM, Gregory Etelson wrote:
> > According to RTE flow user guide, PMD will not keep flow rules after
> > port stop. Application resources that refer to flow rules become
> > obsolete after port stop and must not be used.
> > Testpmd maintains linked list of active flows for each port. Entries
> > in that list are allocated dynamically and must be explicitly released
> > to prevent memory leak.
> > The patch releases testpmd port flow_list that holds remaining flows
> > before port is stopped.
> >
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Gregory Etelson <getelson@nvidia.com>
> > ---
> >  app/test-pmd/testpmd.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> > 33fc0fddf5..0bb192b2f5 100644
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -2806,6 +2806,9 @@ stop_port(portid_t pid)
> >                       }
> >               }
> >
> > +             if (port->flow_list)
> > +                     port_flow_flush(pi);
> > +
> >               if (rte_eth_dev_stop(pi) != 0)
> >                       RTE_LOG(ERR, EAL, "rte_eth_dev_stop failed for
> port %u\n",
> >                               pi);
> >
> 
> port_flow_flush() does rte_flow_flush() which is not strictly required.
> Description sounds like we should cleanup testpmd lists only.

You are right, call to rte_flow_flush() is not required, if testpmd calls port_flow_flush()
as part of port stop sequence, because PMD will remove flows in that scenario.
port_flow_flush() has a general implementation. It destroys all flows without
port state consideration - current or future. In this form, port_flow_flush() can be
called from any testpmd scenario that needs flows destruction.

Regards,
Gregory