linux-kernel - Re: [PATCH v3] perf tools: Fix pattern matching for same substring in different pmu type

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Date:   Tue, 6 Jul 2021 21:44:07 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     Jin Yao <yao.jin@...ux.intel.com>
Cc:     acme@...nel.org, jolsa@...nel.org, peterz@...radead.org,
        mingo@...hat.com, alexander.shishkin@...ux.intel.com,
        Linux-kernel@...r.kernel.org, ak@...ux.intel.com,
        kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v3] perf tools: Fix pattern matching for same substring
 in different pmu type

On Thu, Jul 01, 2021 at 02:42:53PM +0800, Jin Yao wrote:
> Some different pmu types may have same substring. For example,
> on Icelake server, we have pmu types "uncore_imc" and
> "uncore_imc_free_running". Both pmu types have substring "uncore_imc".
> But the parser would wrongly think they are the same pmu type.
> 
> We enable an imc event,
> perf stat -e uncore_imc/event=0xe3/ -a -- sleep 1
> 
> Perf actually expands the event to:
> uncore_imc_0/event=0xe3/
> uncore_imc_1/event=0xe3/
> uncore_imc_2/event=0xe3/
> uncore_imc_3/event=0xe3/
> uncore_imc_4/event=0xe3/
> uncore_imc_5/event=0xe3/
> uncore_imc_6/event=0xe3/
> uncore_imc_7/event=0xe3/
> uncore_imc_free_running_0/event=0xe3/
> uncore_imc_free_running_1/event=0xe3/
> uncore_imc_free_running_3/event=0xe3/
> uncore_imc_free_running_4/event=0xe3/
> 
> That's because the "uncore_imc_free_running" matches the
> pattern "uncore_imc*".
> 
> Now we check that the last characters of pmu name is
> '_<digit>'.
> 
> For example, for pattern "uncore_imc*", "uncore_imc_0" is parsed ok,
> but "uncore_imc_free_running_0" would be failed.
> 
> Fixes: b2b9d3a3f021 ("perf pmu: Support wildcards on pmu name in dynamic pmu events")
> Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>

looks good to me, Kan, Andi?

Acked-by: Jiri Olsa <jolsa@...hat.com>

thanks,
jirka

> ---
>  tools/perf/util/parse-events.y |  2 +-
>  tools/perf/util/pmu.c          | 36 +++++++++++++++++++++++++++++++++-
>  tools/perf/util/pmu.h          |  1 +
>  3 files changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index aba12a4d488e..9321bd0e2f76 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -316,7 +316,7 @@ event_pmu_name opt_pmu_config
>  			if (!strncmp(name, "uncore_", 7) &&
>  			    strncmp($1, "uncore_", 7))
>  				name += 7;
> -			if (!fnmatch(pattern, name, 0)) {
> +			if (!perf_pmu__match(pattern, name, $1)) {
>  				if (parse_events_copy_term_list(orig_terms, &terms))
>  					CLEANUP_YYABORT;
>  				if (!parse_events_add_pmu(_parse_state, list, pmu->name, terms, true, false))
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 88c8ecdc60b0..44b90d638ad5 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -3,6 +3,7 @@
>  #include <linux/compiler.h>
>  #include <linux/string.h>
>  #include <linux/zalloc.h>
> +#include <linux/ctype.h>
>  #include <subcmd/pager.h>
>  #include <sys/types.h>
>  #include <errno.h>
> @@ -17,6 +18,7 @@
>  #include <locale.h>
>  #include <regex.h>
>  #include <perf/cpumap.h>
> +#include <fnmatch.h>
>  #include "debug.h"
>  #include "evsel.h"
>  #include "pmu.h"
> @@ -740,6 +742,27 @@ struct pmu_events_map *__weak pmu_events_map__find(void)
>  	return perf_pmu__find_map(NULL);
>  }
>  
> +static bool perf_pmu__valid_suffix(char *pmu_name, char *tok)
> +{
> +	char *p;
> +
> +	if (strncmp(pmu_name, tok, strlen(tok)))
> +		return false;
> +
> +	p = pmu_name + strlen(tok);
> +	if (*p == 0)
> +		return true;
> +
> +	if (*p != '_')
> +		return false;
> +
> +	++p;
> +	if (*p == 0 || !isdigit(*p))
> +		return false;
> +
> +	return true;
> +}
> +
>  bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
>  {
>  	char *tmp = NULL, *tok, *str;
> @@ -768,7 +791,7 @@ bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
>  	 */
>  	for (; tok; name += strlen(tok), tok = strtok_r(NULL, ",", &tmp)) {
>  		name = strstr(name, tok);
> -		if (!name) {
> +		if (!name || !perf_pmu__valid_suffix((char *)name, tok)) {
>  			res = false;
>  			goto out;
>  		}
> @@ -1872,3 +1895,14 @@ bool perf_pmu__has_hybrid(void)
>  
>  	return !list_empty(&perf_pmu__hybrid_pmus);
>  }
> +
> +int perf_pmu__match(char *pattern, char *name, char *tok)
> +{
> +	if (fnmatch(pattern, name, 0))
> +		return -1;
> +
> +	if (tok && !perf_pmu__valid_suffix(name, tok))
> +		return -1;
> +
> +	return 0;
> +}
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index a790ef758171..926da483a141 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -133,5 +133,6 @@ void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
>  				   char *name);
>  
>  bool perf_pmu__has_hybrid(void);
> +int perf_pmu__match(char *pattern, char *name, char *tok);
>  
>  #endif /* __PMU_H */
> -- 
> 2.17.1
>