[dpdk-dev] Probing the expected state/support of DPDK at armhf

[Ruifeng Wang]

> -----Original Message-----
> From: Christian Ehrhardt <christian.ehrhardt at canonical.com>
> Sent: Monday, November 8, 2021 8:32 PM
> To: Jan Viktorin <viktorin at rehivetech.com>; Ruifeng Wang
> <Ruifeng.Wang at arm.com>; dev <dev at dpdk.org>
> Cc: Luca Boccassi <bluca at debian.org>
> Subject: Probing the expected state/support of DPDK at armhf
> 
> Hi,
> I wanted to ask about the current state of DPDK at armhf (not arm64, that
> seems fine AFAICS).
> Since there are too many arms today, I mean armhf as in [0].
I think armhf in question refers to armv7.

> 
> What I see when building DPDK 21.11 is
> 2973 ../config/meson.build:364:1: ERROR: Problem encountered: Number of
> CPU cores not specified.
> 
> Right now this seems to be broken the same everywhere - Suse [1], fedora
> [2], Debian/Ubuntu [3]
Looks like this happens with native build on armv7 machine. RTE_MAX_LCORE is not set for the build.

> 
> I'm not asking for a fix for this particular issue (although I guess people would
> be happy), but more about the general state of DPDK at armhf.
> 
> Debian and Ubuntu used to build it on armhf as well, but over the recent
> years I feel (no hard data) that usage there was next to none.
> 
> OTOH Thomas said that recently people cared about armv7 [4]
> 
> My suggestion would be to disable the build on armhf in Debian/Ubuntu
> (+elsewhere?) until it reaches a more stable phase and real use-cases.
> But maybe I missed some use-cases, therefore I wanted to reach out to the
> mailing list to probe for more opinions on this.
I'm not aware of amount of users that using DPDK on armv7. But [4] suggests that there is real use case.
I think the build on armhf does have value. It helps to maintain general status on armv7. That is one of
the reason why user [4] can enable armv7 cross compile smoothly.
I suggest to keep the build and fix the failure.

> 
> Thanks for your thoughts on this in advance!
> 
> P.S. If it is meant to work and be supported, then we will need a fix for that
Hi Juraj,
Can you have a look at the issue?

> 
> [0]: https://wiki.debian.org/ArmHardFloatPort
> [1]:
> https://build.opensuse.org/public/build/home:bluca:dpdk/openSUSE_Facto
> ry_ARM/armv7l/dpdk/_log
> [2]:
> https://build.opensuse.org/public/build/home:bluca:dpdk/Fedora_35/armv
> 7l/dpdk/_log
> [3]: https://launchpadlibrarian.net/567810935/buildlog_ubuntu-jammy-
> armhf.dpdk_21.11~rc1-1u~ppa1_BUILDING.txt.gz
> [4]: https://patches.dpdk.org/project/dpdk/patch/20210610111839.7481-1-
> s.chandrakant at globaledgesoft.com/
> 
> --
> Christian Ehrhardt
> Staff Engineer, Ubuntu Server
> Canonical Ltd