[dpdk-dev] [PATCH] doc: document libnuma requirement for NUMA systems

[Kevin Traynor]

On 01/31/2019 05:05 PM, Anatoly Burakov wrote:
> Since 18.05, libnuma is pretty much required on Linux when using
> non-legacy mode, because without it, we cannot know where our
> hugepages are located [1].
> 
> In legacy mode, libnuma is not required because we can still sort
> pages by sockets, as we use pagemap lookup method to figure out
> socket ID's for pages.
> 
> So, document libnuma as required for NUMA systems and non-legacy
> mode.
> 
> [1] https://mails.dpdk.org/archives/dev/2018-December/120490.html
> 

Might as well add to the stable docs also. Picking this commit as it's
where both mode are available

Fixes: 6b42f75632f0 ("eal: enable non-legacy memory mode")
Cc: stable at dpdk.org

> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---
>  doc/guides/linux_gsg/sys_reqs.rst | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/doc/guides/linux_gsg/sys_reqs.rst b/doc/guides/linux_gsg/sys_reqs.rst
> index 8ec3af491..23cfc27ab 100644
> --- a/doc/guides/linux_gsg/sys_reqs.rst
> +++ b/doc/guides/linux_gsg/sys_reqs.rst
> @@ -70,6 +70,14 @@ Compilation of the DPDK
>  
>      * libnuma-dev in Debian/Ubuntu;
>  
> +    .. note::
> +
> +        On systems with NUMA support, `libnuma-dev` (aka `numactl-devel`) is a
> +        recommended dependency when `--legacy-mem` switch is used, and a
> +        *required* dependency if default memory mode is used. While DPDK will
> +        compile and run without `libnuma` even on NUMA-enabled systems, both
> +        usability and performance will be degraded.
> +
>  *   Python, version 2.7+ or 3.2+, to use various helper scripts included in the DPDK package.
>  
>  
> 

Acked-by: Kevin Traynor <ktraynor at redhat.com>