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Date: Thu, 12 Aug 2021 13:14:53 +0100
From: John Garry <john.garry@...wei.com>
To: Jin Yao <yao.jin@...ux.intel.com>, <acme@...nel.org>,
<jolsa@...nel.org>, <peterz@...radead.org>, <mingo@...hat.com>,
<alexander.shishkin@...ux.intel.com>
CC: <Linux-kernel@...r.kernel.org>, <linux-perf-users@...r.kernel.org>,
<ak@...ux.intel.com>, <kan.liang@...el.com>, <yao.jin@...el.com>,
<rickyman7@...il.com>, Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [PATCH v4 1/2] perf pmu: Add PMU alias support
perf pmu: Add x86 PMU alias support
> +char *pmu_find_real_name(const char *name)
> +{
> + static bool cached_list;
> +
> + if (cached_list)
> + return __pmu_find_real_name(name);
> +
> + setup_pmu_alias_list();
> + cached_list = true;
> +
> + return __pmu_find_real_name(name);
> +}
> +
> +char *pmu_find_alias_name(const char *name)
> +{
> + struct perf_pmu_alias_name *pmu;
> +
> + list_for_each_entry(pmu, &pmu_alias_name_list, list) {
> + if (!strcmp(name, pmu->name))
> + return strdup(pmu->alias);
I would not expect a function which does a "find" to duplicate the name.
Same goes for all the other places which does similar.
> + }
> + return NULL;
> +}
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 9321bd0e2f76..d94e48e1ff9b 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -316,7 +316,8 @@ event_pmu_name opt_pmu_config
> if (!strncmp(name, "uncore_", 7) &&
> strncmp($1, "uncore_", 7))
> name += 7;
> - if (!perf_pmu__match(pattern, name, $1)) {
> + if (!perf_pmu__match(pattern, name, $1) ||
> + !perf_pmu__match(pattern, pmu->alias_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 fc683bc41715..796a4be752f4 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -946,6 +946,18 @@ perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
> return NULL;
> }
>
> +char * __weak
> +pmu_find_real_name(const char *name)
> +{
> + return strdup(name);
> +}
That's not finding anything.
> +
> +char * __weak
> +pmu_find_alias_name(const char *name __maybe_unused)
> +{
> + return NULL;
> +}
> +
> static int pmu_max_precise(const char *name)
> {
> char path[PATH_MAX];
> @@ -959,19 +971,25 @@ static int pmu_max_precise(const char *name)
> return max_precise;
> }
>
> -static struct perf_pmu *pmu_lookup(const char *name)
> +static struct perf_pmu *pmu_lookup(const char *lookup_name)
> {
> - struct perf_pmu *pmu;
> + struct perf_pmu *pmu = NULL;
> LIST_HEAD(format);
> LIST_HEAD(aliases);
> __u32 type;
> - bool is_hybrid = perf_pmu__hybrid_mounted(name);
> + bool is_hybrid;
> + char *name = pmu_find_real_name(lookup_name);
> +
> + if (!name)
> + return NULL;
> +
> + is_hybrid = perf_pmu__hybrid_mounted(name);
>
> /*
> * Check pmu name for hybrid and the pmu may be invalid in sysfs
> */
> if (!strncmp(name, "cpu_", 4) && !is_hybrid)
> - return NULL;
> + goto out;
>
> /*
> * The pmu data we store & need consists of the pmu
> @@ -979,23 +997,24 @@ static struct perf_pmu *pmu_lookup(const char *name)
> * now.
> */
> if (pmu_format(name, &format))
> - return NULL;
> + goto out;
>
> /*
> * Check the type first to avoid unnecessary work.
> */
> if (pmu_type(name, &type))
> - return NULL;
> + goto out;
>
> if (pmu_aliases(name, &aliases))
> - return NULL;
> + goto out;
>
> pmu = zalloc(sizeof(*pmu));
> if (!pmu)
> - return NULL;
> + goto out;
>
> pmu->cpus = pmu_cpumask(name);
> - pmu->name = strdup(name);
> + pmu->name = name;
> + pmu->alias_name = pmu_find_alias_name(name);
> pmu->type = type;
> pmu->is_uncore = pmu_is_uncore(name);
> if (pmu->is_uncore)
> @@ -1017,6 +1036,10 @@ static struct perf_pmu *pmu_lookup(const char *name)
>
> pmu->default_config = perf_pmu__get_default_config(pmu);
>
> +out:
> + if (!pmu)
> + free(name);
I don't understand this. There are lots of places this function can fail
, but we don't free memories allocated previously - why just free this one?
> +
> return pmu;
> }
>
> @@ -1025,7 +1048,8 @@ static struct perf_pmu *pmu_find(const char *name)
> struct perf_pmu *pmu;
>
> list_for_each_entry(pmu, &pmus, list)
> - if (!strcmp(pmu->name, name))
> + if (!strcmp(pmu->name, name) ||
> + (pmu->alias_name && !strcmp(pmu->alias_name, name)))
> return pmu;
I'd be inclined to use {} for the list_for_each_entry() call
>
> return NULL;
> @@ -1920,6 +1944,9 @@ bool perf_pmu__has_hybrid(void)
>
> int perf_pmu__match(char *pattern, char *name, char *tok)
> {
> + if (!name)
> + return -1;
> +
> if (fnmatch(pattern, name, 0))
> return -1;
>
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 926da483a141..f6ca9f6a06ef 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -21,6 +21,7 @@ enum {
> #define PERF_PMU_FORMAT_BITS 64
> #define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
> #define CPUS_TEMPLATE_CPU "%s/bus/event_source/devices/%s/cpus"
> +#define MAX_PMU_NAME_LEN 128
>
> struct perf_event_attr;
>
> @@ -32,6 +33,7 @@ struct perf_pmu_caps {
>
> struct perf_pmu {
> char *name;
> + char *alias_name; /* PMU alias name */
useless comment
> char *id;
> __u32 type;
> bool selectable;
> @@ -135,4 +137,7 @@ void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> bool perf_pmu__has_hybrid(void);
> int perf_pmu__match(char *pattern, char *name, char *tok);
>
> +char *pmu_find_real_name(const char *name);
> +char *pmu_find_alias_name(const char *name);
> +
> #endif /* __PMU_H */
>
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