linux-kernel - Re: [RFC V2 1/3] perf, tools: Support wildcards on pmu name in dynamic pmu events

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Date:   Sat, 3 Mar 2018 15:34:36 +0100
From:   Jiri Olsa <jolsa@...hat.com>
To:     Agustin Vega-Frias <agustinv@...eaurora.org>
Cc:     linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Namhyung Kim <namhyung@...nel.org>, timur@...eaurora.org
Subject: Re: [RFC V2 1/3] perf, tools: Support wildcards on pmu name in
 dynamic pmu events

On Fri, Mar 02, 2018 at 06:41:30PM -0500, Agustin Vega-Frias wrote:

SNIP

> 
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 655ecff..a1a01b1 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -175,7 +175,7 @@ bpf_source	[^,{}]+\.c[a-zA-Z0-9._]*
>  num_dec		[0-9]+
>  num_hex		0x[a-fA-F0-9]+
>  num_raw_hex	[a-fA-F0-9]+
> -name		[a-zA-Z_*?][a-zA-Z0-9_*?.]*
> +name		[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_*?\.:]+)?
>  /* If you add a modifier you need to update check_modifier() */
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index e81a20e..c528469 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -8,6 +8,7 @@
> 
>  #define YYDEBUG 1
> 
> +#include <fnmatch.h>
>  #include <linux/compiler.h>
>  #include <linux/list.h>
>  #include <linux/types.h>
> @@ -241,7 +242,7 @@ PE_NAME opt_event_config
>  			if (!strncmp(name, "uncore_", 7) &&
>  			    strncmp($1, "uncore_", 7))
>  				name += 7;
> -			if (!strncmp($1, name, strlen($1))) {
> +			if (!strncmp($1, name, strlen($1)) || !fnmatch($1, name, 0)) {

could we now get rid of the strncmp in here and keep the
glob matching only? I find it confusing now that following
commands give me same results:

	- [root@...va perf]# ./perf stat -e 'cbox/clockticks/' --no-merge -a sleep 1

	 Performance counter stats for 'system wide':

	   <not supported>      uncore_cbox_1/clockticks/                                   
	281,474,957,674,239      uncore_cbox_0/clockticks/                                   

	       1.000958335 seconds time elapsed

	- [root@...va perf]# ./perf stat -e '*cbox*/clockticks/' --no-merge -a sleep 1

	 Performance counter stats for 'system wide':

	   <not supported>      uncore_cbox_1/clockticks/                                   
		 5,427,337      uncore_cbox_0/clockticks/                                   

	       1.000962724 seconds time elapsed

	- [root@...va perf]# ./perf stat -e 'cbox*/clockticks/' --no-merge -a sleep 1

	 Performance counter stats for 'system wide':

	   <not supported>      uncore_cbox_1/clockticks/                                   
	281,474,969,621,374      uncore_cbox_0/clockticks/                                   

	       1.001026179 seconds time elapsed

and this one fails:

	- [root@...va perf]# ./perf stat -e '*cbox/clockticks/' --no-merge -a sleep 1
	event syntax error: '*cbox/clockticks/'
			     \___ Cannot find PMU `*cbox'. Missing kernel support?
	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


despite the fact that it makes as much sense as the previous one: perf stat -e 'cbox*/clockticks/'


I'd think let's keep just the glob matching, so it's clear
you what you use wildcards for.. thoughts?

thanks,
jirka