Hi, David,

Thanks a lot for your helpful reply.

On Fri, Sep 30, 2022 at 12:05 PM zhoumin <zhoumin@loongson.cn> wrote:

On Fri, Sep 30, 2022 at 16:13, David Marchand wrote:

On Fri, Sep 30, 2022 at 10:02 AM Min Zhou <zhoumin@loongson.cn> wrote:

The online documents of LoongArch architecture are here:
     https://loongson.github.io/LoongArch-Documentation/README-EN.html

The latest build tools for LoongArch (binary) can be downloaded from:
     https://github.com/loongson/build-tools

Could you confirm which sources have been used to generate it? and
instructions to compile it?

Only the cross compiler [1] is required. The instructions can be found in
the new added file cross_build_dpdk_for_loongarch.rst. I had added the
CI job for cross compiling DPDK for LoongArch in patch v7 7/7. The CI job
can run successfully if without the GCC warning caused by vhost.

- Sorry, but those instructions are not useful.

Is this architecture support in upstream gcc not functional?

Maybe I missed the information.. I spent some time at the different
links in the docs and in github, but I always end up with a set of
headers, or binaries, and no reference to the exact sources that were
used.
I have limited trust in binaries uploaded somewhere in github.
I don't want to spend more time on this.

What I ask for, is clear instructions how to get the toolchain
sources, and how to generate this toolchain.

- About the vhost compilation issue, a fix in the same area of the
code is in progress.
It will take some time to get the fix.
I will postpone merging the last patch until the vhost fix is ready.
(I am rather confident all of this will be resolved by the time 22.11
is released).

v7:
     - rebase the patchset on the main repository
     - add errno.h to rte_power_intrinsics.c according with
       commit 72b452c5f259

Thanks, I will look at this last revision.


There is still one aspect that is unclear to me.
How will the DPDK community make sure changes won't break this
architecture? (I mean, runtime checks, not only compilation)
IOW, what do you plan to hook to our CI to test patches submitted to
the mailing list?

We can send our machine to UNH lab, but it may take a long time.

GHA seems to be a good choice. However, I found that the codes of CI
runner of GHA [2] are arch-specific. So the CI runner currently cannot
run on
LoongArch machine.

I see.

The better solution is probably to go with "your" own CI so that that
LoongArch has runtime non regression (functional and performance)
tests.
See below.

Are there other CI clients which are not arch-specific and can be used
for DPDK?
We can provide machines accessible by the public network. These machines run
Loongnix-server system which was built based on the source rpms of CentOS 8.
We can deploy DPDK CI client on these machines.

There is no "DPDK CI client" per se.

The DPDK project has a distributed CI made of at least 3 CI entities.

Those CI test patches and post reports via mail: the ovsrobot, Intel
CI and UNH lab.
A CI retrieves patches from patchwork, a set of scripts is available
in https://git.dpdk.org/tools/dpdk-ci/ (especially the poll-pw
script).

Then the way the patches are tested is something each CI handles on its side:
- the ovsrobot creates a branch per series under the ovsrobot/dpdk
github repository, and let GitHub action run (this is how your current
series has been tested in GHA),
- Intel CI have their own tool for which I have little detail,
- UNH lab have their infrastructure too, using some Jenkins iirc. They
provide a dashboard for reports
https://lab.dpdk.org/results/dashboard/ and to get all details and
logs.

The common point is that, at the end of testing a series, a test
report is sent to the (sender-restricted) test-report@ mailing list.

Those reports could be done per patch, but given the amount of patches
on the dev@ mailing list, the consensus is to test the whole series
and report back against the last patch of a series.

All of this is gathered by patchwork (the details of how it is done
are not 100% clear to me, maybe Ali can confirm later if a
modification is required).

If you look at your v7 series, you will see:
https://patchwork.dpdk.org/project/dpdk/list/?series=24929&state=%2A&archive=both
- ovsrobot: ci/github-robot link
http://mails.dpdk.org/archives/test-report/2022-September/310836.html
- Intel CI: ci/Intel-* links, for example on the compilation test
http://mails.dpdk.org/archives/test-report/2022-September/310822.html
- UNH lab: all ci/iol-* links, for example on the compilation test
http://mails.dpdk.org/archives/test-report/2022-September/310834.html

So what LoongSoon could do is setup some Loongnix systems with a
similar infrastructure and provide (native?) compilation and runtime
test reports.

I Cc'd a few people involved in all this.
And there is the ci@ mailing list where all CI people can discuss.