[dpdk-dev] [PATCH v4] eal/cpuflags: add x86 based cpu flags

[Thomas Monjalon]

16/04/2020 13:00, Kevin Laatz:
> This patch adds CPU flags which will enable the detection of ISA
> features available on more recent x86 based CPUs.
[...]
> --- a/devtools/libabigail.abignore
> +++ b/devtools/libabigail.abignore
> +; Ignore this enum update as it should not be allocated by the application
> +[suppress_type]
> +	type_kind = enum
> +	name = rte_cpu_flag_t
> +	changed_enumerators = RTE_CPUFLAG_NUMFLAGS

The justification is not correct.
The application is allowed to use RTE_CPUFLAG_NUMFLAGS in array allocation.
But no API is returning a CPU flag, so the new flags will remain unknown
to the application.

However, there is a behaviour change:
The functions rte_cpu_get_flag_name() and rte_cpu_get_flag_enabled()
will now accept new values, which were previously considered as an error.
Is it an ABI breakage? I would say no.


PS: Who is REALLY maintaining the ABI?
We really miss someone who carefully check all these things,
and take care of the doc and tooling.