diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/tools/perf/util/pmu.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/tools/perf/util/pmu.c')
-rw-r--r-- | kernel/tools/perf/util/pmu.c | 992 |
1 files changed, 992 insertions, 0 deletions
diff --git a/kernel/tools/perf/util/pmu.c b/kernel/tools/perf/util/pmu.c new file mode 100644 index 000000000..48411674d --- /dev/null +++ b/kernel/tools/perf/util/pmu.c @@ -0,0 +1,992 @@ +#include <linux/list.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; + + 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); + + 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, FILE *file) +{ + struct perf_pmu_alias *alias; + char buf[256]; + int ret; + + ret = fread(buf, 1, sizeof(buf), file); + if (ret == 0) + return -EINVAL; + buf[ret] = 0; + + 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, buf); + if (ret) { + free(alias); + return ret; + } + + alias->name = strdup(name); + /* + * 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 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 *__attribute__((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, char *name) +{ + struct perf_pmu_format *format; + + list_for_each_entry(format, formats, list) + if (!strcmp(format->name, name)) + return format; + + return NULL; +} + +/* + * 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); + } +} + +/* + * 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; +} + +/* + * 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 perf_pmu_format *format; + __u64 *vp; + __u64 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); + 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); + return -EINVAL; + } + + if (pmu_resolve_param_term(term, head_terms, &val)) + return -EINVAL; + } else + return -EINVAL; + + 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_term *term; + + list_for_each_entry(term, head_terms, list) { + if (pmu_config_term(formats, attr, term, head_terms, zero)) + 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) +{ + bool zero = !!pmu->default_config; + + attr->type = pmu->type; + return perf_pmu__config_terms(&pmu->format, attr, head_terms, zero); +} + +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) { + 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) + 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; +} |