Commit 44462430 authored by Jin Yao's avatar Jin Yao Committed by Arnaldo Carvalho de Melo
Browse files

perf pmu: Save detected hybrid pmus to a global pmu list 



We identify the cpu_core pmu and cpu_atom pmu by explicitly
checking following files:

For cpu_core, checks:
"/sys/bus/event_source/devices/cpu_core/cpus"

For cpu_atom, checks:
"/sys/bus/event_source/devices/cpu_atom/cpus"

If the 'cpus' file exists and it has data, the pmu exists.

But in order not to hardcode the "cpu_core" and "cpu_atom",
and make the code in a generic way.

So if the path "/sys/bus/event_source/devices/cpu_xxx/cpus" exists, the
hybrid pmu exists. All the detected hybrid pmus are linked to a global
list 'perf_pmu__hybrid_pmus' and then next we just need to iterate the
list to get all hybrid pmu by using perf_pmu__for_each_hybrid_pmu.

Signed-off-by: default avatarJin Yao <yao.jin@linux.intel.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210427070139.25256-6-yao.jin@linux.intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 32705de7

tools/perf/util/Build

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ perf-y += parse-events-bison.o 
perf-y += pmu.o

perf-y += pmu-flex.o

perf-y += pmu-bison.o

perf-y += pmu-hybrid.o

perf-y += trace-event-read.o

perf-y += trace-event-info.o

perf-y += trace-event-scripting.o

tools/perf/util/pmu-hybrid.c

0 → 100644
+49 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <linux/list.h>

#include <linux/compiler.h>

#include <linux/string.h>

#include <linux/zalloc.h>

#include <sys/types.h>

#include <errno.h>

#include <fcntl.h>

#include <sys/stat.h>

#include <unistd.h>

#include <stdio.h>

#include <stdbool.h>

#include <stdarg.h>

#include <locale.h>

#include <api/fs/fs.h>

#include "fncache.h"

#include "pmu-hybrid.h"



LIST_HEAD(perf_pmu__hybrid_pmus);



bool perf_pmu__hybrid_mounted(const char *name)

{

	char path[PATH_MAX];

	const char *sysfs;

	FILE *file;

	int n, cpu;



	if (strncmp(name, "cpu_", 4))

		return false;



	sysfs = sysfs__mountpoint();

	if (!sysfs)

		return false;



	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name);

	if (!file_available(path))

		return false;



	file = fopen(path, "r");

	if (!file)

		return false;



	n = fscanf(file, "%u", &cpu);

	fclose(file);

	if (n <= 0)

		return false;



	return true;

}

tools/perf/util/pmu-hybrid.h

0 → 100644
+18 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __PMU_HYBRID_H

#define __PMU_HYBRID_H



#include <linux/perf_event.h>

#include <linux/compiler.h>

#include <linux/list.h>

#include <stdbool.h>

#include "pmu.h"



extern struct list_head perf_pmu__hybrid_pmus;



#define perf_pmu__for_each_hybrid_pmu(pmu)	\

	list_for_each_entry(pmu, &perf_pmu__hybrid_pmus, hybrid_list)



bool perf_pmu__hybrid_mounted(const char *name);



#endif /* __PMU_HYBRID_H */

tools/perf/util/pmu.c

+8 −1
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include "string2.h"

#include "strbuf.h"

#include "fncache.h"

#include "pmu-hybrid.h"



struct perf_pmu perf_pmu__fake;
@@ -613,7 +614,6 @@ static struct perf_cpu_map *__pmu_cpumask(const char *path) 
 */

#define SYS_TEMPLATE_ID	"./bus/event_source/devices/%s/identifier"

#define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"

#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"



static struct perf_cpu_map *pmu_cpumask(const char *name)

{
@@ -645,6 +645,9 @@ static bool pmu_is_uncore(const char *name) 
	char path[PATH_MAX];

	const char *sysfs;



	if (perf_pmu__hybrid_mounted(name))

		return false;



	sysfs = sysfs__mountpoint();

	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);

	return file_available(path);
@@ -951,6 +954,7 @@ static struct perf_pmu *pmu_lookup(const char *name) 
	pmu->is_uncore = pmu_is_uncore(name);

	if (pmu->is_uncore)

		pmu->id = pmu_id(name);

	pmu->is_hybrid = perf_pmu__hybrid_mounted(name);

	pmu->max_precise = pmu_max_precise(name);

	pmu_add_cpu_aliases(&aliases, pmu);

	pmu_add_sys_aliases(&aliases, pmu);
@@ -962,6 +966,9 @@ static struct perf_pmu *pmu_lookup(const char *name) 
	list_splice(&aliases, &pmu->aliases);

	list_add_tail(&pmu->list, &pmus);



	if (pmu->is_hybrid)

		list_add_tail(&pmu->hybrid_list, &perf_pmu__hybrid_pmus);



	pmu->default_config = perf_pmu__get_default_config(pmu);



	return pmu;

tools/perf/util/pmu.h

+4 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/bitmap.h>

#include <linux/compiler.h>

#include <linux/perf_event.h>

#include <linux/list.h>

#include <stdbool.h>

#include "parse-events.h"

#include "pmu-events/pmu-events.h"
@@ -19,6 +20,7 @@ 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"



struct perf_event_attr;
@@ -34,6 +36,7 @@ struct perf_pmu { 
	__u32 type;

	bool selectable;

	bool is_uncore;

	bool is_hybrid;

	bool auxtrace;

	int max_precise;

	struct perf_event_attr *default_config;
@@ -42,6 +45,7 @@ struct perf_pmu { 
	struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */

	struct list_head caps;    /* HEAD struct perf_pmu_caps -> list */

	struct list_head list;    /* ELEM */

	struct list_head hybrid_list;

};



extern struct perf_pmu perf_pmu__fake;