From: Ian Rogers Date: Thu, 24 Aug 2023 04:13:21 +0000 (-0700) Subject: perf pmu: Parse sysfs events directly from a file X-Git-Tag: v6.6.7~1921^2~43 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=edb217ff14fb98c74373f65f8ac08b9bfe26e344;p=platform%2Fkernel%2Flinux-starfive.git perf pmu: Parse sysfs events directly from a file Rather than read a sysfs events file into a 256 byte char buffer, pass the FILE* directly to the lex/yacc parser. This avoids there being a maximum events file size. While changing the API, constify some arguments to remove unnecessary casts. Allocating the read buffer decreases the performance of pmu-scan by around 3%. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Gaosheng Cui Cc: Ingo Molnar Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Rob Herring Link: https://lore.kernel.org/r/20230824041330.266337-10-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c index 27944c1..3180779 100644 --- a/tools/perf/arch/x86/util/intel-pt.c +++ b/tools/perf/arch/x86/util/intel-pt.c @@ -74,7 +74,7 @@ static int intel_pt_parse_terms_with_default(struct perf_pmu *pmu, INIT_LIST_HEAD(terms); - err = parse_events_terms(terms, str); + err = parse_events_terms(terms, str, /*input=*/ NULL); if (err) goto out_free; diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c index 658fb95..d86076d 100644 --- a/tools/perf/tests/parse-events.c +++ b/tools/perf/tests/parse-events.c @@ -2472,7 +2472,7 @@ static int test_term(const struct terms_test *t) INIT_LIST_HEAD(&terms); - ret = parse_events_terms(&terms, t->str); + ret = parse_events_terms(&terms, t->str, /*input=*/ NULL); if (ret) { pr_debug("failed to parse terms '%s', err %d\n", t->str , ret); diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 781747b..c71e135 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -1715,6 +1715,7 @@ int parse_events_name(struct list_head *list, const char *name) } static int parse_events__scanner(const char *str, + FILE *input, struct parse_events_state *parse_state) { YY_BUFFER_STATE buffer; @@ -1725,7 +1726,10 @@ static int parse_events__scanner(const char *str, if (ret) return ret; - buffer = parse_events__scan_string(str, scanner); + if (str) + buffer = parse_events__scan_string(str, scanner); + else + parse_events_set_in(input, scanner); #ifdef PARSER_DEBUG parse_events_debug = 1; @@ -1733,8 +1737,10 @@ static int parse_events__scanner(const char *str, #endif ret = parse_events_parse(parse_state, scanner); - parse_events__flush_buffer(buffer, scanner); - parse_events__delete_buffer(buffer, scanner); + if (str) { + parse_events__flush_buffer(buffer, scanner); + parse_events__delete_buffer(buffer, scanner); + } parse_events_lex_destroy(scanner); return ret; } @@ -1742,7 +1748,7 @@ static int parse_events__scanner(const char *str, /* * parse event config string, return a list of event terms. */ -int parse_events_terms(struct list_head *terms, const char *str) +int parse_events_terms(struct list_head *terms, const char *str, FILE *input) { struct parse_events_state parse_state = { .terms = NULL, @@ -1750,7 +1756,7 @@ int parse_events_terms(struct list_head *terms, const char *str) }; int ret; - ret = parse_events__scanner(str, &parse_state); + ret = parse_events__scanner(str, input, &parse_state); if (!ret) { list_splice(parse_state.terms, terms); @@ -2001,7 +2007,7 @@ int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filte }; int ret, ret2; - ret = parse_events__scanner(str, &parse_state); + ret = parse_events__scanner(str, /*input=*/ NULL, &parse_state); if (!ret && list_empty(&parse_state.list)) { WARN_ONCE(true, "WARNING: event parser found nothing\n"); diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h index 411f69b2..c7f7794 100644 --- a/tools/perf/util/parse-events.h +++ b/tools/perf/util/parse-events.h @@ -9,6 +9,7 @@ #include #include #include +#include #include struct evsel; @@ -42,7 +43,7 @@ static inline int parse_events(struct evlist *evlist, const char *str, int parse_event(struct evlist *evlist, const char *str); -int parse_events_terms(struct list_head *terms, const char *str); +int parse_events_terms(struct list_head *terms, const char *str, FILE *input); int parse_filter(const struct option *opt, const char *str, int unset); int exclude_perf(const struct option *opt, const char *arg, int unset); diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 9ba9ac3..263c63e 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -280,7 +280,7 @@ out: return ret; } -static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, int dirfd, char *name) +static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, int dirfd, const char *name) { struct stat st; ssize_t sret; @@ -312,7 +312,7 @@ error: return ret; } -static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, int dirfd, char *name) +static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, int dirfd, const char *name) { char path[PATH_MAX]; ssize_t sret; @@ -343,7 +343,7 @@ error: } static int -perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, int dirfd, char *name) +perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, int dirfd, const char *name) { char path[PATH_MAX]; int fd; @@ -361,7 +361,7 @@ perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, int dirfd, char *name) } static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias, - int dirfd, char *name) + int dirfd, const char *name) { char path[PATH_MAX]; int fd; @@ -454,8 +454,9 @@ static bool perf_pmu_merge_alias(struct perf_pmu_alias *newalias, return false; } -static int __perf_pmu__new_alias(struct list_head *list, int dirfd, char *name, - char *desc, char *val, const struct pmu_event *pe) +static int perf_pmu__new_alias(struct list_head *list, int dirfd, const char *name, + const char *desc, const char *val, FILE *val_fd, + const struct pmu_event *pe) { struct parse_events_term *term; struct perf_pmu_alias *alias; @@ -484,7 +485,7 @@ static int __perf_pmu__new_alias(struct list_head *list, int dirfd, char *name, alias->snapshot = false; alias->deprecated = deprecated; - ret = parse_events_terms(&alias->terms, val); + ret = parse_events_terms(&alias->terms, val, val_fd); if (ret) { pr_err("Cannot parse alias %s: %d\n", val, ret); free(alias); @@ -541,23 +542,6 @@ static int __perf_pmu__new_alias(struct list_head *list, int dirfd, char *name, return 0; } -static int perf_pmu__new_alias(struct list_head *list, int dirfd, char *name, FILE *file) -{ - char buf[256]; - int ret; - - ret = fread(buf, 1, sizeof(buf), file); - if (ret == 0) - return -EINVAL; - - buf[ret] = 0; - - /* Remove trailing newline from sysfs file */ - strim(buf); - - return __perf_pmu__new_alias(list, dirfd, name, NULL, buf, NULL); -} - static inline bool pmu_alias_info_file(char *name) { size_t len; @@ -613,7 +597,8 @@ static int pmu_aliases_parse(int dirfd, struct list_head *head) continue; } - if (perf_pmu__new_alias(head, dirfd, name, file) < 0) + if (perf_pmu__new_alias(head, dirfd, name, /*desc=*/ NULL, + /*val=*/ NULL, file, /*pe=*/ NULL) < 0) pr_debug("Cannot set up %s\n", name); fclose(file); } @@ -866,7 +851,7 @@ static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe, struct list_head *head = vdata; /* need type casts to override 'const' */ - __perf_pmu__new_alias(head, -1, (char *)pe->name, (char *)pe->desc, (char *)pe->event, pe); + perf_pmu__new_alias(head, -1, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL, pe); return 0; } @@ -907,11 +892,12 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe, if (!strcmp(pmu->id, pe->compat) && pmu_uncore_alias_match(pe->pmu, pmu->name)) { - __perf_pmu__new_alias(idata->head, -1, - (char *)pe->name, - (char *)pe->desc, - (char *)pe->event, - pe); + perf_pmu__new_alias(idata->head, -1, + pe->name, + pe->desc, + pe->event, + /*val_fd=*/ NULL, + pe); } return 0;