Re: [PATCH RFC] interconnect: Add interconnect_graph file to debugfs

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Nov 14, 2019 at 02:50:49AM +0200, Leonard Crestez wrote:
> The interconnect graphs can be difficult to understand and the current
> "interconnect_summary" file doesn't even display links in any way.
> 
> Add a new "interconnect_graph" file to debugfs in the graphviz "dot"
> format which describes interconnect providers, nodes and links.
> 
> The file is human-readable and can be visualized by piping through
> graphviz. Example:
> 
> ssh $TARGET cat /sys/kernel/debug/interconnect/interconnect_graph \
> 	| dot -Tsvg > interconnect_graph.svg

You might want to document this somewhere so we don't all have to go dig
it out of the changelog every time we want to look at this file.


> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/interconnect/core.c | 66 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
> 
> Example output as a github gist:
> https://gist.github.com/cdleonard/2f74a7efe74587e3d4b57cf7983b46a8
> 
> The qcs404 driver was hacked to probe on imx, the links to "0" seem to
> from incorrect trailing 0s on DEFINE_QNODE. Possibly fallout from
> switching to ARRAY_SIZE(__VA_ARGS__)?
> 
> I'm not sure that "graphviz" is allowed as an output format even in
> debugfs.

Why not!  :)

This is great, I love it, nice job, no objection from me.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>