Re: [dpdk-dev] [PATCH v4] RSS key use with testpmd

[Phil Yang <Phil.Yang@arm.com>]

Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> Sent: Saturday, October 10, 2020 2:53 AM
> To: oulijun <oulijun@huawei.com>; wenzhuo.lu@intel.com;
> beilei.xing@intel.com; adrien.mazarguil@6wind.com; Phil Yang
> <Phil.Yang@arm.com>
> Cc: dev@dpdk.org; linuxarm@huawei.com
> Subject: Re: [PATCH v4] RSS key use with testpmd
> 
> On 10/9/2020 1:09 PM, oulijun wrote:
> >
> >
> > 在 2020/9/30 21:17, Ferruh Yigit 写道:
> >> On 9/24/2020 2:45 PM, Lijun Ou wrote:
> >>> Consider the follow usage with testpmd:
> >>> 1. first, startup testpmd:
> >>> testpmd> show port 0 rss-hash key
> >>> RSS functions:
> >>>   all ipv4-frag ipv4-other ipv6-frag ipv6-other ip
> >>> RSS key:
> >>>
> 6D5A56DA255B0EC24167253D43A38FB0D0CA2BCBAE7B30B477CB2DA38030F
> >>> 20C6A42B73BBEAC01FA
> >>> 2. create a rss rule
> >>> testpmd> flow create 0 ingress pattern eth / ipv4 / udp / end actions rss
> \
> >>> types ipv4-udp end queues end / end
> >>>
> >>> 3. show rss-hash key
> >>> testpmd> show port 0 rss-hash key
> >>> RSS functions:
> >>>   all ipv4-udp udp
> >>> RSS key:
> >>>
> 74657374706D6427732064656661756C74205253532068617368206B65792C206F
> >>> 76657272696465
> >>>
> >>> As a result, the step 3 with RSS key and the step 1 RSS key
> >>> is not the same. The patch[1] to solve the above problems.
> >>>
> >>
> >> This is interesting, can you please provide above information in the
> commit
> >> log too?
> >>
> > Yes， I submitted detailed operation information in patch v3 as a commit,
> and
> > Yang suggested that the operation information be included in the cover
> letter.
>  >
> 
> OK, understood.
> Only, commands helped me to understand the problem, it is easy to grasp
> the
> issue with samples, so I thought it may help others later in if it is in the
> commit log, since cover letter won't be visible in the git repo.
> 
> @Phil, will you be OK to have them in the commit log if the checkpatch
> warnings
> fixed?

Yeah. It is OK. 


> 
> >> Also can you please provide the details on why this happens, callstack can
> help?
> >>
> > When you start the testpmd, the pmd driver initializes the RSS
> configuration.
> > Generally, the recommended RSS hash key is used as the default key in the
> > driver. In addition, the default key is different from the default RSS flow in
> > testpmd without specifying RSS hash key.
> > So， if you do not specify the RSS key when creating an RSS rule, the
> testpmd
> > uses the default key as the default RSS key of the RSS rule.As a result, you
> may
> > mistakenly consider that the RSS key in use is the valid default key of the
> NIC,
> > actually, the key and the valid default key of the NIC are two values.
> 
> Above description looks good, can you include this to the commit log please?
> 
> >> Thanks,
> >> ferruh
> >>
> >>
> >>> Lijun Ou (1):
> >>>    app/testpmd: fix the default RSS key configuration
> >>>
> >>>   app/test-pmd/cmdline_flow.c | 8 ++++++++
> >>>   1 file changed, 8 insertions(+)
> >>>
> >>
> >> .
> >>