RE: [PATCH 2/4] eventdev: have ethernet Rx adapter appropriately report idle

["Naga Harish K, S V" <s.v.naga.harish.k@intel.com>]

> -----Original Message-----
> From: Jerin Jacob <jerinjacobk@gmail.com>
> Sent: Friday, October 14, 2022 11:07 PM
> To: mattias.ronnblom <mattias.ronnblom@ericsson.com>
> Cc: Naga Harish K, S V <s.v.naga.harish.k@intel.com>; Jayatheerthan, Jay
> <jay.jayatheerthan@intel.com>; Carrillo, Erik G <Erik.G.Carrillo@intel.com>;
> Gujjar, Abhinandan S <abhinandan.gujjar@intel.com>; Jerin Jacob
> <jerinj@marvell.com>; dev@dpdk.org; Van Haaren, Harry
> <harry.van.haaren@intel.com>; hofors@lysator.liu.se
> Subject: Re: [PATCH 2/4] eventdev: have ethernet Rx adapter appropriately
> report idle
> 
> On Thu, Oct 13, 2022 at 3:23 PM Mattias Rönnblom
> <mattias.ronnblom@ericsson.com> wrote:
> >
> > On 2022-10-13 03:32, Naga Harish K, S V wrote:
> > >
> > >
> > >> -----Original Message-----
> > >> From: Jayatheerthan, Jay <jay.jayatheerthan@intel.com>
> > >> Sent: Tuesday, October 11, 2022 12:40 PM
> > >> To: mattias.ronnblom <mattias.ronnblom@ericsson.com>; Carrillo,
> > >> Erik G <erik.g.carrillo@intel.com>; Gujjar, Abhinandan S
> > >> <abhinandan.gujjar@intel.com>; Jerin Jacob <jerinj@marvell.com>;
> > >> Naga Harish K, S V <s.v.naga.harish.k@intel.com>
> > >> Cc: dev@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>;
> > >> hofors@lysator.liu.se; mattias.ronnblom
> > >> <mattias.ronnblom@ericsson.com>
> > >> Subject: RE: [PATCH 2/4] eventdev: have ethernet Rx adapter
> > >> appropriately report idle

nitpick: 
the headline can be modified as "eventdev/eth_rx:" for Rx adapter patches,
to make it consistent with the currently following procedure.

Similar change for other patches of other adapters.

After these changes, my "Reviewed-by: " tag can be added for patches 2 and 3 (Rx adapter and Tx adapter).

-Harish

> > >>
> > >> @Harish, Could you review the patch ?
> > >>
> > >> -Jay
> > >>
> > >>>
> > >>>   done:
> > >>> -   rx_adapter->stats.rx_intr_packets += nb_rx;
> > >>> +   if (nb_rx > 0) {
> > >
> > > How are the performance numbers before and after this patch?
> > > Trying to understand the performance impact, as new condition is added
> to the service function Datapath.
> > >
> > I haven't tested the RX and TX adapters separately, but if you run
> > them on the same core, I get the following result:
> >
> > Without patches, with stats disabled: 16,0 Mpps Without patches, with
> > stats enabled: 16,1 Mpps With patches, with stats disabled: 16,1 Mpps
> > With patches, with stats enabled: 16,2 Mpps
> >
> > So these patches, with this particular hardware, compiler, and test
> > application, adding a tiny bit of additional logic actually make the
> > RX+TX adapter perform better. This is contrary to what you might
> > RX+expect,
> > and I'm sure YMMV.
> >
> > Enabling service core statistics (which boils down to a 2x rdtsc and
> > some cheap arithmetic in rte_service.c) actually make the RX+TX
> > adapter core perform better, both before and after this patchset. Also
> > contrary to what you might expect.
> >
> > The results are consistent across multiple runs.
> >
> > GCC 11.2.0 and AMD Zen 3 @ 3,7 GHz. Event device is DSW and I/O is the
> > ring Ethdev.
> 
> @Naga Harish K, S V @Jayatheerthan, Jay  @Gujjar, Abhinandan S  @Erik
> Gabriel Carrillo Planning to take this series for rc2. If there are no other
> comments, I will merge the series then.