[dpdk-dev] Using C11 atomic semantic

[Thomas Monjalon]

20/07/2020 17:44, Honnappa Nagarahalli:
> From: Thomas Monjalon <thomas at monjalon.net>
> > 
> > In the techboard of April 22, it has been decided to block patches using
> > rte_atomicNN_xx and rte_smp_*mb APIs, starting DPDK 20.08.
> > Meeting minutes:
> > 	http://mails.dpdk.org/archives/dev/2020-April/165143.html
> > Deprecation notice:
> > 	http://doc.dpdk.org/guides/rel_notes/deprecation.html
> > 
> > Some doc has been submitted to help understanding how to manage atomics:
> > 	http://doc	.dpdk.org/guides/prog_guide/writing_efficient_code.html#locks-and-
> > atomic-operations
> > 
> > Unfortunately the tool to check new code was merged last week:
> > 	http://git.dpdk.org/dpdk/commit/?id=f1602b4a86
> > 
> > As a consequence, I propose to apply the "reject rule" starting DPDK 20.11.
> 
> As far as I know no patch with rte_atomic has gone in 20.08 so far. Are there any patches in RC2/RC3 that need rte_atomic APIs?

Yes we have the case of an additional call added in 20.08-rc2
in mlx5 (not yet converted to C11 atomics).

> > Can we make this rule better advertised with an announce message?
> 
> Do you mean an email on dpdk-announce mailing list?

Yes

> > Are the current technical explanations enough?
> 
> The documentation patch you referenced above covers most common cases people will encounter. Even the rte_ring/rte_stack algorithms work on the same principles.
> 
> > If not, it would be wonderful to have a blog post explaining the details, as
> > part of an announce.
> 
> This is in the works. The plan is to send it to you soon and get it out along with the release.

Great