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Message-ID: <YS6CCNpd3+557fQZ@krava>
Date: Tue, 31 Aug 2021 21:24:56 +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, linux-perf-users@...r.kernel.org,
ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com,
rickyman7@...il.com, john.garry@...wei.com,
Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [PATCH v5 1/2] perf pmu: Add PMU alias support
On Tue, Aug 17, 2021 at 01:19:32PM +0800, Jin Yao wrote:
> From: Kan Liang <kan.liang@...ux.intel.com>
>
> A perf uncore PMU may have two PMU names, a real name and an alias. The
> alias is exported at /sys/bus/event_source/devices/uncore_*/alias.
> The perf tool should support the alias as well.
>
> Add alias_name in the struct perf_pmu to store the alias. For the PMU
> which doesn't have an alias. It's NULL.
>
> Introduce two X86 specific functions to retrieve the real name and the
> alias separately.
>
> Only go through the sysfs to retrieve the mapping between the real name
> and the alias once. The result is cached in a list, uncore_pmu_list.
>
> Nothing changed for the other ARCHs.
>
> With the patch, the perf tool can monitor the PMU with either the real
> name or the alias.
>
> Use the real name,
> $ perf stat -e uncore_cha_2/event=1/ -x,
> 4044879584,,uncore_cha_2/event=1/,2528059205,100.00,,
>
> Use the alias,
> $ perf stat -e uncore_type_0_2/event=1/ -x,
> 3659675336,,uncore_type_0_2/event=1/,2287306455,100.00,,
>
> Co-developed-by: Jin Yao <yao.jin@...ux.intel.com>
> Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>
> Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
> Reviewed-by: Andi Kleen <ak@...ux.intel.com>
SNIP
> +static char *__pmu_find_real_name(const char *name)
> +{
> + struct perf_pmu_alias_name *pmu;
> +
> + list_for_each_entry(pmu, &pmu_alias_name_list, list) {
> + if (!strcmp(name, pmu->alias))
> + return pmu->name;
> + }
> +
> + return (char *)name;
> +}
> +
> +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;
should this one call setup_pmu_alias_list as well?
> +
> + list_for_each_entry(pmu, &pmu_alias_name_list, list) {
> + if (!strcmp(name, pmu->name))
> + return pmu->alias;
> + }
> + 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 6cdbee8a12e7..9df874155370 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -945,6 +945,18 @@ perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
> return NULL;
> }
>
> +char * __weak
> +pmu_find_real_name(const char *name)
> +{
> + return (char *)name;
> +}
> +
> +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];
> @@ -958,13 +970,15 @@ 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;
> LIST_HEAD(format);
> LIST_HEAD(aliases);
> __u32 type;
> + char *name = pmu_find_real_name(lookup_name);
> bool is_hybrid = perf_pmu__hybrid_mounted(name);
> + char *alias_name;
>
> /*
> * Check pmu name for hybrid and the pmu may be invalid in sysfs
> @@ -995,6 +1009,9 @@ static struct perf_pmu *pmu_lookup(const char *name)
>
> pmu->cpus = pmu_cpumask(name);
> pmu->name = strdup(name);
> + alias_name = pmu_find_alias_name(name);
> + if (alias_name)
> + pmu->alias_name = strdup(alias_name);
please add pmu->name and pmu->alias_name check
thanks,
jirka
> pmu->type = type;
> pmu->is_uncore = pmu_is_uncore(name);
> if (pmu->is_uncore)
> @@ -1023,9 +1040,11 @@ 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))
> + list_for_each_entry(pmu, &pmus, list) {
> + if (!strcmp(pmu->name, name) ||
> + (pmu->alias_name && !strcmp(pmu->alias_name, name)))
> return pmu;
> + }
>
> return NULL;
> }
> @@ -1919,6 +1938,9 @@ 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 033e8211c025..6b122f97acf3 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;
> char *id;
> __u32 type;
> bool selectable;
> @@ -136,4 +138,7 @@ 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 */
> --
> 2.17.1
>
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