Re: [dpdk-dev] [PATCH] ppc64: fix compilation of when AltiVec is enabled

[dwilder <dwilder@us.ibm.com>]

On 2018-11-07 02:03, Thomas Monjalon wrote:
> 05/11/2018 22:20, Pradeep Satyanarayana:
>> From: Thomas Monjalon <thomas@monjalon.net>
>> > 30/08/2018 13:58, Christian Ehrhardt:
>> > > On Thu, Aug 30, 2018 Takeshi T Yoshimura <TYOS@jp.ibm.com> wrote:
>> > > > Hi,
>> > > > I could reproduce the issue you reported in 18.08 with my ppc64le
>> > > > box with RedHat 7.5 and GCC4.8.
>> > > > The patch resolved the issue in my environment. Thanks!
>> > >
>> > > I added your test (tanks) and Adrien's extensive review/discussion as
>> > > tags and also addressed a few checkpatch findings.
>> > > V2 is up on the list now ...
>> > >
>> > > > I am a bit newbie in dpdk-dev, but I will try contacting Chao
>> > > > and other IBM guys... Sorry for our slow reply.
>> > >
>> > > Thanks for your participation Takeshi,
>> > > we at least now have had a few replies after Thomas used the
>> > > superpowers of "CPT. CAPSLOCK" \o/.
>> > >
>> > > I also have a call later today to make sure this is brought up
>> > > inside IBM to make sure someone is maintaining it for real.
>> >
>> > Summary of the situation:
>> >    - I used caps lock on August 30th
>> >    - We got replies on the ML in the next 2 days (Alfredo, Chao, Takeshi)
>> >    - On September 3rd, Adrien raised a major issue for C++ with the fix v3
>> > 		http://mails.dpdk.org/archives/dev/2018-September/110733.html
>> >    - Another email about a possible GCC fix on September 5th (David Wilder)
>> 
>> As Dave mentioned that is only expected in GCC 9.
>> 
>> >    - There was a private reply on September 27th, confirming an IBM support
>> >    - and nothing else
>> >
>> > Nobody at IBM requests to get a compilation fix for ppc64.
>> 
>> Yes, we do need fixes for ppc64.
>> 
>> (1) 
>> http://mails.dpdk.org/archives/dev/2018-August/110499.html
>> (2) 
>> http://mails.dpdk.org/archives/dev/2018-September/110961.html
>> 
>> Based on the above 2 URLs (tested both by Takeshi and David Wiler), we
>> assumed that it would get picked up in 18.11.
>> We have been more focussed on 17.11 (and likely dropped
>> the ball on 18.11)
>> since 17.11 is an LTS release and we have had lots of problems on 
>> ppc64.
> 
> Note that 18.11 is also LTS.
> 
>> Should be submitting patch to fix those issues shortly.
> 
> Sorry, I have some doubts for two reasons:
> 	- track records
> 	- technical reality: there is no perfect solution outside of GCC
> 
>> We have built 18.11-rc1 with the fix above (1), and it does work on
>> ppc64le.
> 
> But it would break C++ applications.
> 
>> An updated version of:
>> 
>> (3) 
>> http://mails.dpdk.org/archives/dev/2018-August/109926.html
>> 
>> also builds on ppc64.  The latter has the advantage of possibly not
>> breaking existing applications.
> 

I am not seeing any build breaks on upstream code with the 
net-mlx5-fix-build-on-PPC64.patch applied.

> But it fixes only mlx5.
> stdbool is used in many other places.
> Which PMDs are you compiling?

CONFIG_RTE_LIBRTE_ARK_PMD=y
CONFIG_RTE_LIBRTE_AXGBE_PMD=y
CONFIG_RTE_LIBRTE_BNXT_PMD=y
CONFIG_RTE_LIBRTE_CXGBE_PMD=y
CONFIG_RTE_LIBRTE_DPAA_PMD=y
CONFIG_RTE_LIBRTE_DPAA2_PMD=y
CONFIG_RTE_LIBRTE_ENETC_PMD=y
CONFIG_RTE_LIBRTE_ENA_PMD=y
CONFIG_RTE_LIBRTE_EM_PMD=y
CONFIG_RTE_LIBRTE_IGB_PMD=y
CONFIG_RTE_LIBRTE_I40E_PMD=y
CONFIG_RTE_LIBRTE_AVF_PMD=y
CONFIG_RTE_LIBRTE_MLX5_PMD=y
CONFIG_RTE_LIBRTE_NFP_PMD=y
CONFIG_RTE_LIBRTE_QEDE_PMD=y
CONFIG_RTE_LIBRTE_THUNDERX_NICVF_PMD=y
CONFIG_RTE_LIBRTE_LIO_PMD=y
CONFIG_RTE_LIBRTE_OCTEONTX_PMD=y
CONFIG_RTE_LIBRTE_VIRTIO_PMD=y
CONFIG_RTE_LIBRTE_NETVSC_PMD=y
CONFIG_RTE_LIBRTE_VDEV_NETVSC_PMD=y
CONFIG_RTE_LIBRTE_IFC_PMD=y
CONFIG_RTE_TEST_PMD=y

> Are you compiling examples?

Yes, no build issues seen.

> 
>> > And there was no issue raised after 18.11-rc1 release.
>> > I guess it means DPDK is not used on ppc64.
>> > In this case, we should mark the ppc port as unmaintained for 18.11.
>> >
>> > OR SHOULD I USE MY CAPS LOCK AGAIN?
>> 
>> Thanks for your patience while we iron out the issues.
>> Hopefully, we don't need the CAPS LOCK again.
> 
> We have to mention the ppc64 incompatibility in 18.11 release notes.
> Either it stays as is and we declare DPDK 18.11 not supported on
> IBM platforms, or we fix it and document the limitations.

If net-mlx5-fix-build-on-PPC64.patch is accepted I feel power can be 
listed as supported for 18.11.