- 根目录:
- tools
- perf
- util
- pmu.c
#include <linux/list.h>
#include <linux/compiler.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdarg.h>
#include <dirent.h>
#include <api/fs/fs.h>
#include <locale.h>
#include "util.h"
#include "pmu.h"
#include "parse-events.h"
#include "cpumap.h"
struct perf_pmu_format {
char *name;
int value;
DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
struct list_head list;
};
#define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
int perf_pmu_parse(struct list_head *list, char *name);
extern FILE *perf_pmu_in;
static LIST_HEAD(pmus);
/*
* Parse & process all the sysfs attributes located under
* the directory specified in 'dir' parameter.
*/
int perf_pmu__format_parse(char *dir, struct list_head *head)
{
struct dirent *evt_ent;
DIR *format_dir;
int ret = 0;
format_dir = opendir(dir);
if (!format_dir)
return -EINVAL;
while (!ret && (evt_ent = readdir(format_dir))) {
char path[PATH_MAX];
char *name = evt_ent->d_name;
FILE *file;
if (!strcmp(name, ".") || !strcmp(name, ".."))
continue;
snprintf(path, PATH_MAX, "%s/%s", dir, name);
ret = -EINVAL;
file = fopen(path, "r");
if (!file)
break;
perf_pmu_in = file;
ret = perf_pmu_parse(head, name);
fclose(file);
}
closedir(format_dir);
return ret;
}
/*
* Reading/parsing the default pmu format definition, which should be
* located at:
* /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
*/
static int pmu_format(const char *name, struct list_head *format)
{
struct stat st;
char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return -1;
snprintf(path, PATH_MAX,
"%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);
if (stat(path, &st) < 0)
return 0; /* no error if format does not exist */
if (perf_pmu__format_parse(path, format))
return -1;
return 0;
}
static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
{
struct stat st;
ssize_t sret;
char scale[128];
int fd, ret = -1;
char path[PATH_MAX];
const char *lc;
snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
fd = open(path, O_RDONLY);
if (fd == -1)
return -1;
if (fstat(fd, &st) < 0)
goto error;
sret = read(fd, scale, sizeof(scale)-1);
if (sret < 0)
goto error;
if (scale[sret - 1] == '\n')
scale[sret - 1] = '\0';
else
scale[sret] = '\0';
/*
* save current locale
*/
lc = setlocale(LC_NUMERIC, NULL);
/*
* force to C locale to ensure kernel
* scale string is converted correctly.
* kernel uses default C locale.
*/
setlocale(LC_NUMERIC, "C");
alias->scale = strtod(scale, NULL);
/* restore locale */
setlocale(LC_NUMERIC, lc);
ret = 0;
error:
close(fd);
return ret;
}
static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
{
char path[PATH_MAX];
ssize_t sret;
int fd;
snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
fd = open(path, O_RDONLY);
if (fd == -1)
return -1;
sret = read(fd, alias->unit, UNIT_MAX_LEN);
if (sret < 0)
goto error;
close(fd);
if (alias->unit[sret - 1] == '\n')
alias->unit[sret - 1] = '\0';
else
alias->unit[sret] = '\0';
return 0;
error:
close(fd);
alias->unit[0] = '\0';
return -1;
}
static int
perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, char *dir, char *name)
{
char path[PATH_MAX];
int fd;
snprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);
fd = open(path, O_RDONLY);
if (fd == -1)
return -1;
close(fd);
alias->per_pkg = true;
return 0;
}
static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
char *dir, char *name)
{
char path[PATH_MAX];
int fd;
snprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
fd = open(path, O_RDONLY);
if (fd == -1)
return -1;
alias->snapshot = true;
close(fd);
return 0;
}
static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
char *desc __maybe_unused, char *val)
{
struct perf_pmu_alias *alias;
int ret;
alias = malloc(sizeof(*alias));
if (!alias)
return -ENOMEM;
INIT_LIST_HEAD(&alias->terms);
alias->scale = 1.0;
alias->unit[0] = '\0';
alias->per_pkg = false;
ret = parse_events_terms(&alias->terms, val);
if (ret) {
pr_err("Cannot parse alias %s: %d\n", val, ret);
free(alias);
return ret;
}
alias->name = strdup(name);
if (dir) {
/*
* load unit name and scale if available
*/
perf_pmu__parse_unit(alias, dir, name);
perf_pmu__parse_scale(alias, dir, name);
perf_pmu__parse_per_pkg(alias, dir, name);
perf_pmu__parse_snapshot(alias, dir, name);
}
list_add_tail(&alias->list, list);
return 0;
}
static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
{
char buf[256];
int ret;
ret = fread(buf, 1, sizeof(buf), file);
if (ret == 0)
return -EINVAL;
buf[ret] = 0;
return __perf_pmu__new_alias(list, dir, name, NULL, buf);
}
static inline bool pmu_alias_info_file(char *name)
{
size_t len;
len = strlen(name);
if (len > 5 && !strcmp(name + len - 5, ".unit"))
return true;
if (len > 6 && !strcmp(name + len - 6, ".scale"))
return true;
if (len > 8 && !strcmp(name + len - 8, ".per-pkg"))
return true;
if (len > 9 && !strcmp(name + len - 9, ".snapshot"))
return true;
return false;
}
/*
* Process all the sysfs attributes located under the directory
* specified in 'dir' parameter.
*/
static int pmu_aliases_parse(char *dir, struct list_head *head)
{
struct dirent *evt_ent;
DIR *event_dir;
int ret = 0;
event_dir = opendir(dir);
if (!event_dir)
return -EINVAL;
while (!ret && (evt_ent = readdir(event_dir))) {
char path[PATH_MAX];
char *name = evt_ent->d_name;
FILE *file;
if (!strcmp(name, ".") || !strcmp(name, ".."))
continue;
/*
* skip info files parsed in perf_pmu__new_alias()
*/
if (pmu_alias_info_file(name))
continue;
snprintf(path, PATH_MAX, "%s/%s", dir, name);
ret = -EINVAL;
file = fopen(path, "r");
if (!file)
break;
ret = perf_pmu__new_alias(head, dir, name, file);
fclose(file);
}
closedir(event_dir);
return ret;
}
/*
* Reading the pmu event aliases definition, which should be located at:
* /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
*/
static int pmu_aliases(const char *name, struct list_head *head)
{
struct stat st;
char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return -1;
snprintf(path, PATH_MAX,
"%s/bus/event_source/devices/%s/events", sysfs, name);
if (stat(path, &st) < 0)
return 0; /* no error if 'events' does not exist */
if (pmu_aliases_parse(path, head))
return -1;
return 0;
}
static int pmu_alias_terms(struct perf_pmu_alias *alias,
struct list_head *terms)
{
struct parse_events_term *term, *cloned;
LIST_HEAD(list);
int ret;
list_for_each_entry(term, &alias->terms, list) {
ret = parse_events_term__clone(&cloned, term);
if (ret) {
parse_events__free_terms(&list);
return ret;
}
list_add_tail(&cloned->list, &list);
}
list_splice(&list, terms);
return 0;
}
/*
* Reading/parsing the default pmu type value, which should be
* located at:
* /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
*/
static int pmu_type(const char *name, __u32 *type)
{
struct stat st;
char path[PATH_MAX];
FILE *file;
int ret = 0;
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return -1;
snprintf(path, PATH_MAX,
"%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);
if (stat(path, &st) < 0)
return -1;
file = fopen(path, "r");
if (!file)
return -EINVAL;
if (1 != fscanf(file, "%u", type))
ret = -1;
fclose(file);
return ret;
}
/* Add all pmus in sysfs to pmu list: */
static void pmu_read_sysfs(void)
{
char path[PATH_MAX];
DIR *dir;
struct dirent *dent;
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return;
snprintf(path, PATH_MAX,
"%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
dir = opendir(path);
if (!dir)
return;
while ((dent = readdir(dir))) {
if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
continue;
/* add to static LIST_HEAD(pmus): */
perf_pmu__find(dent->d_name);
}
closedir(dir);
}
static struct cpu_map *pmu_cpumask(const char *name)
{
struct stat st;
char path[PATH_MAX];
FILE *file;
struct cpu_map *cpus;
const char *sysfs = sysfs__mountpoint();
if (!sysfs)
return NULL;
snprintf(path, PATH_MAX,
"%s/bus/event_source/devices/%s/cpumask", sysfs, name);
if (stat(path, &st) < 0)
return NULL;
file = fopen(path, "r");
if (!file)
return NULL;
cpus = cpu_map__read(file);
fclose(file);
return cpus;
}
struct perf_event_attr * __weak
perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
{
return NULL;
}
static struct perf_pmu *pmu_lookup(const char *name)
{
struct perf_pmu *pmu;
LIST_HEAD(format);
LIST_HEAD(aliases);
__u32 type;
/*
* The pmu data we store & need consists of the pmu
* type value and format definitions. Load both right
* now.
*/
if (pmu_format(name, &format))
return NULL;
if (pmu_aliases(name, &aliases))
return NULL;
if (pmu_type(name, &type))
return NULL;
pmu = zalloc(sizeof(*pmu));
if (!pmu)
return NULL;
pmu->cpus = pmu_cpumask(name);
INIT_LIST_HEAD(&pmu->format);
INIT_LIST_HEAD(&pmu->aliases);
list_splice(&format, &pmu->format);
list_splice(&aliases, &pmu->aliases);
pmu->name = strdup(name);
pmu->type = type;
list_add_tail(&pmu->list, &pmus);
pmu->default_config = perf_pmu__get_default_config(pmu);
return pmu;
}
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))
return pmu;
return NULL;
}
struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
{
/*
* pmu iterator: If pmu is NULL, we start at the begin,
* otherwise return the next pmu. Returns NULL on end.
*/
if (!pmu) {
pmu_read_sysfs();
pmu = list_prepare_entry(pmu, &pmus, list);
}
list_for_each_entry_continue(pmu, &pmus, list)
return pmu;
return NULL;
}
struct perf_pmu *perf_pmu__find(const char *name)
{
struct perf_pmu *pmu;
/*
* Once PMU is loaded it stays in the list,
* so we keep us from multiple reading/parsing
* the pmu format definitions.
*/
pmu = pmu_find(name);
if (pmu)
return pmu;
return pmu_lookup(name);
}
static struct perf_pmu_format *
pmu_find_format(struct list_head *formats, const char *name)
{
struct perf_pmu_format *format;
list_for_each_entry(format, formats, list)
if (!strcmp(format->name, name))
return format;
return NULL;
}
__u64 perf_pmu__format_bits(struct list_head *formats, const char *name)
{
struct perf_pmu_format *format = pmu_find_format(formats, name);
__u64 bits = 0;
int fbit;
if (!format)
return 0;
for_each_set_bit(fbit, format->bits, PERF_PMU_FORMAT_BITS)
bits |= 1ULL << fbit;
return bits;
}
/*
* Sets value based on the format definition (format parameter)
* and unformated value (value parameter).
*/
static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
bool zero)
{
unsigned long fbit, vbit;
for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {
if (!test_bit(fbit, format))
continue;
if (value & (1llu << vbit++))
*v |= (1llu << fbit);
else if (zero)
*v &= ~(1llu << fbit);
}
}
static __u64 pmu_format_max_value(const unsigned long *format)
{
int w;
w = bitmap_weight(format, PERF_PMU_FORMAT_BITS);
if (!w)
return 0;
if (w < 64)
return (1ULL << w) - 1;
return -1;
}
/*
* Term is a string term, and might be a param-term. Try to look up it's value
* in the remaining terms.
* - We have a term like "base-or-format-term=param-term",
* - We need to find the value supplied for "param-term" (with param-term named
* in a config string) later on in the term list.
*/
static int pmu_resolve_param_term(struct parse_events_term *term,
struct list_head *head_terms,
__u64 *value)
{
struct parse_events_term *t;
list_for_each_entry(t, head_terms, list) {
if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
if (!strcmp(t->config, term->config)) {
t->used = true;
*value = t->val.num;
return 0;
}
}
}
if (verbose)
printf("Required parameter '%s' not specified\n", term->config);
return -1;
}
static char *pmu_formats_string(struct list_head *formats)
{
struct perf_pmu_format *format;
char *str;
struct strbuf buf;
unsigned i = 0;
if (!formats)
return NULL;
strbuf_init(&buf, 0);
/* sysfs exported terms */
list_for_each_entry(format, formats, list)
strbuf_addf(&buf, i++ ? ",%s" : "%s",
format->name);
str = strbuf_detach(&buf, NULL);
strbuf_release(&buf);
return str;
}
/*
* Setup one of config[12] attr members based on the
* user input data - term parameter.
*/
static int pmu_config_term(struct list_head *formats,
struct perf_event_attr *attr,
struct parse_events_term *term,
struct list_head *head_terms,
bool zero, struct parse_events_error *err)
{
struct perf_pmu_format *format;
__u64 *vp;
__u64 val, max_val;
/*
* If this is a parameter we've already used for parameterized-eval,
* skip it in normal eval.
*/
if (term->used)
return 0;
/*
* Hardcoded terms should be already in, so nothing
* to be done for them.
*/
if (parse_events__is_hardcoded_term(term))
return 0;
format = pmu_find_format(formats, term->config);
if (!format) {
if (verbose)
printf("Invalid event/parameter '%s'\n", term->config);
if (err) {
char *pmu_term = pmu_formats_string(formats);
err->idx = term->err_term;
err->str = strdup("unknown term");
err->help = parse_events_formats_error_string(pmu_term);
free(pmu_term);
}
return -EINVAL;
}
switch (format->value) {
case PERF_PMU_FORMAT_VALUE_CONFIG:
vp = &attr->config;
break;
case PERF_PMU_FORMAT_VALUE_CONFIG1:
vp = &attr->config1;
break;
case PERF_PMU_FORMAT_VALUE_CONFIG2:
vp = &attr->config2;
break;
default:
return -EINVAL;
}
/*
* Either directly use a numeric term, or try to translate string terms
* using event parameters.
*/
if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
val = term->val.num;
else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
if (strcmp(term->val.str, "?")) {
if (verbose) {
pr_info("Invalid sysfs entry %s=%s\n",
term->config, term->val.str);
}
if (err) {
err->idx = term->err_val;
err->str = strdup("expected numeric value");
}
return -EINVAL;
}
if (pmu_resolve_param_term(term, head_terms, &val))
return -EINVAL;
} else
return -EINVAL;
max_val = pmu_format_max_value(format->bits);
if (val > max_val) {
if (err) {
err->idx = term->err_val;
if (asprintf(&err->str,
"value too big for format, maximum is %llu",
(unsigned long long)max_val) < 0)
err->str = strdup("value too big for format");
return -EINVAL;
}
/*
* Assume we don't care if !err, in which case the value will be
* silently truncated.
*/
}
pmu_format_value(format->bits, val, vp, zero);
return 0;
}
int perf_pmu__config_terms(struct list_head *formats,
struct perf_event_attr *attr,
struct list_head *head_terms,
bool zero, struct parse_events_error *err)
{
struct parse_events_term *term;
list_for_each_entry(term, head_terms, list) {
if (pmu_config_term(formats, attr, term, head_terms,
zero, err))
return -EINVAL;
}
return 0;
}
/*
* Configures event's 'attr' parameter based on the:
* 1) users input - specified in terms parameter
* 2) pmu format definitions - specified by pmu parameter
*/
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct list_head *head_terms,
struct parse_events_error *err)
{
bool zero = !!pmu->default_config;
attr->type = pmu->type;
return perf_pmu__config_terms(&pmu->format, attr, head_terms,
zero, err);
}
static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
struct parse_events_term *term)
{
struct perf_pmu_alias *alias;
char *name;
if (parse_events__is_hardcoded_term(term))
return NULL;
if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
if (term->val.num != 1)
return NULL;
if (pmu_find_format(&pmu->format, term->config))
return NULL;
name = term->config;
} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
if (strcasecmp(term->config, "event"))
return NULL;
name = term->val.str;
} else {
return NULL;
}
list_for_each_entry(alias, &pmu->aliases, list) {
if (!strcasecmp(alias->name, name))
return alias;
}
return NULL;
}
static int check_info_data(struct perf_pmu_alias *alias,
struct perf_pmu_info *info)
{
/*
* Only one term in event definition can
* define unit, scale and snapshot, fail
* if there's more than one.
*/
if ((info->unit && alias->unit) ||
(info->scale && alias->scale) ||
(info->snapshot && alias->snapshot))
return -EINVAL;
if (alias->unit)
info->unit = alias->unit;
if (alias->scale)
info->scale = alias->scale;
if (alias->snapshot)
info->snapshot = alias->snapshot;
return 0;
}
/*
* Find alias in the terms list and replace it with the terms
* defined for the alias
*/
int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
struct perf_pmu_info *info)
{
struct parse_events_term *term, *h;
struct perf_pmu_alias *alias;
int ret;
info->per_pkg = false;
/*
* Mark unit and scale as not set
* (different from default values, see below)
*/
info->unit = NULL;
info->scale = 0.0;
info->snapshot = false;
list_for_each_entry_safe(term, h, head_terms, list) {
alias = pmu_find_alias(pmu, term);
if (!alias)
continue;
ret = pmu_alias_terms(alias, &term->list);
if (ret)
return ret;
ret = check_info_data(alias, info);
if (ret)
return ret;
if (alias->per_pkg)
info->per_pkg = true;
list_del(&term->list);
free(term);
}
/*
* if no unit or scale foundin aliases, then
* set defaults as for evsel
* unit cannot left to NULL
*/
if (info->unit == NULL)
info->unit = "";
if (info->scale == 0.0)
info->scale = 1.0;
return 0;
}
int perf_pmu__new_format(struct list_head *list, char *name,
int config, unsigned long *bits)
{
struct perf_pmu_format *format;
format = zalloc(sizeof(*format));
if (!format)
return -ENOMEM;
format->name = strdup(name);
format->value = config;
memcpy(format->bits, bits, sizeof(format->bits));
list_add_tail(&format->list, list);
return 0;
}
void perf_pmu__set_format(unsigned long *bits, long from, long to)
{
long b;
if (!to)
to = from;
memset(bits, 0, BITS_TO_BYTES(PERF_PMU_FORMAT_BITS));
for (b = from; b <= to; b++)
set_bit(b, bits);
}
static int sub_non_neg(int a, int b)
{
if (b > a)
return 0;
return a - b;
}
static char *format_alias(char *buf, int len, struct perf_pmu *pmu,
struct perf_pmu_alias *alias)
{
struct parse_events_term *term;
int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
list_for_each_entry(term, &alias->terms, list) {
if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
used += snprintf(buf + used, sub_non_neg(len, used),
",%s=%s", term->config,
term->val.str);
}
if (sub_non_neg(len, used) > 0) {
buf[used] = '/';
used++;
}
if (sub_non_neg(len, used) > 0) {
buf[used] = '\0';
used++;
} else
buf[len - 1] = '\0';
return buf;
}
static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
struct perf_pmu_alias *alias)
{
snprintf(buf, len, "%s OR %s/%s/", alias->name, pmu->name, alias->name);
return buf;
}
static int cmp_string(const void *a, const void *b)
{
const char * const *as = a;
const char * const *bs = b;
return strcmp(*as, *bs);
}
void print_pmu_events(const char *event_glob, bool name_only)
{
struct perf_pmu *pmu;
struct perf_pmu_alias *alias;
char buf[1024];
int printed = 0;
int len, j;
char **aliases;
pmu = NULL;
len = 0;
while ((pmu = perf_pmu__scan(pmu)) != NULL) {
list_for_each_entry(alias, &pmu->aliases, list)
len++;
if (pmu->selectable)
len++;
}
aliases = zalloc(sizeof(char *) * len);
if (!aliases)
goto out_enomem;
pmu = NULL;
j = 0;
while ((pmu = perf_pmu__scan(pmu)) != NULL) {
list_for_each_entry(alias, &pmu->aliases, list) {
char *name = format_alias(buf, sizeof(buf), pmu, alias);
bool is_cpu = !strcmp(pmu->name, "cpu");
if (event_glob != NULL &&
!(strglobmatch(name, event_glob) ||
(!is_cpu && strglobmatch(alias->name,
event_glob))))
continue;
if (is_cpu && !name_only)
name = format_alias_or(buf, sizeof(buf), pmu, alias);
aliases[j] = strdup(name);
if (aliases[j] == NULL)
goto out_enomem;
j++;
}
if (pmu->selectable &&
(event_glob == NULL || strglobmatch(pmu->name, event_glob))) {
char *s;
if (asprintf(&s, "%s//", pmu->name) < 0)
goto out_enomem;
aliases[j] = s;
j++;
}
}
len = j;
qsort(aliases, len, sizeof(char *), cmp_string);
for (j = 0; j < len; j++) {
if (name_only) {
printf("%s ", aliases[j]);
continue;
}
printf(" %-50s [Kernel PMU event]\n", aliases[j]);
printed++;
}
if (printed && pager_in_use())
printf("\n");
out_free:
for (j = 0; j < len; j++)
zfree(&aliases[j]);
zfree(&aliases);
return;
out_enomem:
printf("FATAL: not enough memory to print PMU events\n");
if (aliases)
goto out_free;
}
bool pmu_have_event(const char *pname, const char *name)
{
struct perf_pmu *pmu;
struct perf_pmu_alias *alias;
pmu = NULL;
while ((pmu = perf_pmu__scan(pmu)) != NULL) {
if (strcmp(pname, pmu->name))
continue;
list_for_each_entry(alias, &pmu->aliases, list)
if (!strcmp(alias->name, name))
return true;
}
return false;
}
static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
{
struct stat st;
char path[PATH_MAX];
const char *sysfs;
sysfs = sysfs__mountpoint();
if (!sysfs)
return NULL;
snprintf(path, PATH_MAX,
"%s" EVENT_SOURCE_DEVICE_PATH "%s/%s", sysfs, pmu->name, name);
if (stat(path, &st) < 0)
return NULL;
return fopen(path, "r");
}
int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt,
...)
{
va_list args;
FILE *file;
int ret = EOF;
va_start(args, fmt);
file = perf_pmu__open_file(pmu, name);
if (file) {
ret = vfscanf(file, fmt, args);
fclose(file);
}
va_end(args);
return ret;
}