Re: XDP maintainer match (Was [PATCH v2 0/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring)

Jakub Kicinski
2020-11-19T17:59:39Z

On Thu, 19 Nov 2020 09:09:53 -0800 Joe Perches wrote:
> On Thu, 2020-11-19 at 17:35 +0100, Jesper Dangaard Brouer wrote:
> > On Thu, 19 Nov 2020 07:46:34 -0800 Jakub Kicinski <kuba@kernel.org> wrote:
>
> > I think it is a good idea to change the keyword (K:), but I'm not sure
> > this catch what we want, maybe it does. The pattern match are meant to
> > catch drivers containing XDP related bits.
> >
> > Previously Joe Perches <joe@perches.com> suggested this pattern match,
> > which I don't fully understand... could you explain Joe?
> >
> >   (?:\b|_)xdp(?:\b|_)
>
> This regex matches only:
>
> xdp
> xdp_<anything>
> <anything>_xdp_<anything>
> <anything>_xdp
>
> > For the filename (N:) regex match, I'm considering if we should remove
> > it and list more files explicitly. I think normal glob * pattern
> > works, which should be sufficient.
>
> Lists are generally more specific than regex globs.

Checking like Alexei did it seems Joe's version is faster and better:

$ git grep -l -E "[^a-z0-9]xdp[^a-z0-9]" | wc -l
295
$ git grep -l -E '(\b|_)xdp(\b|_)' | wc -l
297
$ time git grep -l -E '(\b|_)xdp(\b|_)' > /tmp/a

real 0m5.171s
user 0m32.657s
sys 0m0.664s
$ time git grep -l -E "[^a-z0-9]xdp[^a-z0-9]" > /tmp/b

real 0m16.627s
user 1m48.149s
sys 0m0.977s
09:56 linux$ diff /tmp/a /tmp/b
4d3
< Documentation/networking/index.rst
189d187
< samples/bpf/.gitignore

Joe would you like to send a patch, or should I?