linux-kernel - Re: [PATCH 3/3] perf parse: Allow names to start with digits

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Date: Sun, 7 Apr 2024 11:32:31 -0700
From: Ian Rogers <irogers@...gle.com>
To: Dominique Martinet <asmadeus@...ewreck.org>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>, Jiri Olsa <jolsa@...nel.org>, 
	Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Namhyung Kim <namhyung@...nel.org>, Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, 
	Adrian Hunter <adrian.hunter@...el.com>, linux-perf-users@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] perf parse: Allow names to start with digits

On Sun, Apr 7, 2024 at 5:38 AM Dominique Martinet
<asmadeus@...ewreck.org> wrote:
>
> Dominique Martinet wrote on Sun, Apr 07, 2024 at 09:18:21PM +0900:
> > diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> > index e86c45675e1d..41c30ff29783 100644
> > --- a/tools/perf/util/parse-events.l
> > +++ b/tools/perf/util/parse-events.l
> > @@ -158,7 +158,7 @@ event             [^,{}/]+
> >  num_dec              [0-9]+
> >  num_hex              0x[a-fA-F0-9]{1,16}
> >  num_raw_hex  [a-fA-F0-9]{1,16}
> > -name         [a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]!\-]*
> > +name         [a-zA-Z0-9_*?\[\]][a-zA-Z0-9_*?.\[\]!\-]*
>
> grmbl sorry I guess I didn't actually test this two years ago (?!), or
> used it differently (commit message is weird and also needs fixing,
> perf probe -e 9p:* does not make sense) or something changed but
> that's not enough:
>
> ----
> $ sudo ./perf trace -e 9p:9p_fid_ref
> event syntax error: '9p:9p_fid_ref'
>                      \___ parser error
> Run 'perf list' for a list of valid events
> ----
>
> Adding 0-9 to name_tag as well makes perf trace works.
>
> I'm not sure what name_minus is for but I did't need to add that one in
> my test.
>
> That also highlights that the test I added isn't sufficient, if someone
> familiar with the code could hint at a better place to test please tell!
> Otherwise I'll have a look next weekend, I need to get back to my 9p
> bugs now I've got a working perf command..
>
> >  name_tag     [\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
> >  name_minus   [a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
> >  drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?
> >

Try adding PARSER_DEBUG=1 to your command line, I need to do the following:
```
$ make EXTRA_CFLAGS="-Wno-error=redundant-decls" PARSER_DEBUG=1
```
For your example it seems to parse with the changes, but I see (which
should be expected):
```
event syntax error: '9p:9p_fid_ref'
                    \___ unknown tracepoint

Error:  File /sys/kernel/tracing//events/9p/9p_fid_ref not found.
Hint:   Perhaps this kernel misses some CONFIG_ setting to enable this feature?.

Run 'perf list' for a list of valid events

Usage: perf stat [<options>] [<command>]

   -e, --event <event>   event selector. use 'perf list' to list
available events
```
I think Jiri's e-mail should be jolsa@...nel.org.

Thanks,
Ian

> --
> Dominique Martinet | Asmadeus