On Fri, Sep 22, 2023 at 11:38:38AM +0100, Bruce Richardson wrote:
> On Fri, Sep 22, 2023 at 11:37:20AM +0200, David Marchand wrote:
> > In some really specific cases, it may be needed to get a detailed
> > information on the processor running a DPDK application for drivers to
> > achieve better performance, or for matters that concern only them.
> >
> > Those information are highly arch-specific and require a specific API.
> >
> > Introduce a set of functions to get brand, family and model of a x86
> > processor.
> > Those functions do not make sense on other arches and a
> > driver must first check rte_cpu_is_x86() before anything else.
> >
> > Signed-off-by: David Marchand <david.march...@redhat.com>
> > ---
>
> Couple of thoughts, having had a few minutes to process this.
>
> * Rather than rte_cpu_is_x86() API, we could go a general API called
> rte_cpu_arch() which returns either a string, or an enum value. Within
> that, rather than #ifdefs, the actual return value could just be a define
> placed by meson in the rte_build_config.h file. The list of families
> according to meson are [1] - we'd just need to merge the 32 and 64-bit
> variants into one in the meson file.
>
We already have the architecture family in meson computed as the
"arch_subdir". Exposing that to the C code and wrapping as EAL function
might look like below (adding to eal.h for convenience).
Thoughts?
/Bruce
diff --git a/lib/eal/include/rte_eal.h b/lib/eal/include/rte_eal.h
index 53c4a5519e..39f65d0e0c 100644
--- a/lib/eal/include/rte_eal.h
+++ b/lib/eal/include/rte_eal.h
@@ -517,6 +517,24 @@ __rte_internal
int
rte_eal_parse_coremask(const char *coremask, int *cores);
+enum rte_arch_family {
+ rte_cpu_arch_arm,
+ rte_cpu_arch_loongarch,
+ rte_cpu_arch_ppc,
+ rte_cpu_arch_riscv,
+ rte_cpu_arch_x86,
+};
+
+/**
+ * Return the architecture family of the current CPU
+ */
+static inline enum rte_arch_family
+rte_eal_get_arch_family(void)
+{
+ /* take value from build config set by meson */
+ return RTE_ARCH_FAMILY;
+}
+
#ifdef __cplusplus
}
#endif
diff --git a/meson.build b/meson.build
index 2e6e546d20..45e22daeb1 100644
--- a/meson.build
+++ b/meson.build
@@ -63,6 +63,7 @@ elif host_machine.cpu_family().startswith('ppc')
elif host_machine.cpu_family().startswith('riscv')
arch_subdir = 'riscv'
endif
+dpdk_conf.set('RTE_ARCH_FAMILY', 'rte_cpu_arch_' + arch_subdir)
# configure the build, and make sure configs here and in config folder are
# able to be included in any file. We also store a global array of include dirs
