Re: [PATCH v3 04/26] config: add separate defines for max Rx and Tx queues

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

On Thu, Oct 10, 2024 at 09:27:27AM -0700, Stephen Hemminger wrote:
> On Tue, 10 Sep 2024 10:54:37 +0800
> fengchengwen <fengchengwen@huawei.com> wrote:
> 
> > On 2024/8/14 18:49, Bruce Richardson wrote:
> > > Rather than having a single define for maximum queues per ethernet port,
> > > we can set the max values for Rx queues and Tx queue independently. This
> > > allows future memory saving for apps which only need large numbers of Rx
> > > queues or only large numbers of Tx queues.
> > > 
> > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > > Acked-by: Morten Brørup <mb@smartsharesystems.com>
> > > ---
> > >  config/rte_config.h                    | 2 ++
> > >  doc/guides/rel_notes/release_24_11.rst | 6 ++++++
> > >  2 files changed, 8 insertions(+)
> > > 
> > > diff --git a/config/rte_config.h b/config/rte_config.h
> > > index d67ff77c71..2c11b4eeec 100644
> > > --- a/config/rte_config.h
> > > +++ b/config/rte_config.h
> > > @@ -65,6 +65,8 @@
> > >  
> > >  /* ether defines */
> > >  #define RTE_MAX_QUEUES_PER_PORT 1024
> > > +#define RTE_MAX_ETHPORT_RX_QUEUES 1024
> > > +#define RTE_MAX_ETHPORT_TX_QUEUES 1024  
> > 
> > The Rx Queues != Tx Queues is not a mainstream scenario (at least from most of DPDK user as I know),
> > rename it (not separate Rx/Tx) with eth meaning and make it as a compile option is enough.
> 
> 
> Agree, allowing max Tx != Rx creates more test cases and other things.
> Lets not open up that can of worms.

I fail to see why it would be that problematic requiring additional test
cases. I also think it's reasonable to give that level of control -
thinking particularly of cases where one side may require thousands of
queues e.g. the rte_tm cases with thousands of TX queues - you'll pay a
large penalty for the other side's (RX) data-structures unnecessarily.

/Bruce