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

[Jakub Kicinski]

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@xxxxxxxxxx> 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@xxxxxxxxxxx> 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?