RE: [PATCH v1] net/i40e: remove redundant number of packets check

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> Sent: Friday, March 4, 2022 7:10 PM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> <feifei.wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Ruifeng Wang <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> <thomas@monjalon.net>; David Marchand <david.marchand@redhat.com>
> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets
> check
> 
> On 3/4/2022 1:23 AM, Zhang, Qi Z wrote:
> >
> >
> >> -----Original Message-----
> >> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> >> Sent: Friday, March 4, 2022 12:44 AM
> >> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> >> <feifei.wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> >> Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> >> <bruce.richardson@intel.com>; Ananyev, Konstantin
> >> <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> >> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> >> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> >> <thomas@monjalon.net>; David Marchand
> <david.marchand@redhat.com>
> >> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets
> >> check
> >>
> >> On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Feifei Wang <feifei.wang2@arm.com>
> >>>> Sent: Thursday, March 3, 2022 9:54 AM
> >>>> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> >>>> <drc@linux.vnet.ibm.com>; Richardson, Bruce
> >>>> <bruce.richardson@intel.com>; Ananyev, Konstantin
> >>>> <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> >>>> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang
> <feifei.wang2@arm.com>;
> >>>> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >>>> Subject: [PATCH v1] net/i40e: remove redundant number of packets
> >>>> check
> >>>>
> >>>> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure
> >>>> nb_pkts does not cross rs_thresh.
> >>>>
> >>>> However, in i40e_xmit_fixed_burst_vec_xx function, this check will
> >>>> be performed again. To improve code, delete this redundant check.
> >>>>
> >>>> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >>>> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> >>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >>>
> >>> Applied to dpdk-next-net-intel.
> >>>
> >>
> >> Hi Qi,
> >>
> >> This patch is not acked by the i40e maintainers.
> >>
> >> And this is changing the datapath for the -rc3, two weeks before the
> >> release. Is it tested enough?
> >>
> >> What is the gain with this patch, I don't see any numbers in the commit log.
> >> If the gain is small, can we postpone this patch to next release
> >> instead of getting it for -rc3?
> >
> > The patch applied the same thing as below which I have reviewed.
> > https://patchwork.dpdk.org/project/dpdk/patch/20220222224818.8612-1-
> ka
> > thleen.capella@arm.com/
> >
> > I didn't see the risk of having it, and I will add a "reviewed-by" to avoid
> confusion, but if you think it's risky, we can still defer it to next-net.
> >
> 
> Code change looks simple, but risk is more theoretical to get a datapath code
> optimization close to the release, and Feifei reported that there is no visible
> performance gain.
> So I think safer to postpone to next release if you don't object.

Re-applied to dpdk-next-net-intel.

Thanks
Qi