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author | Ian Rogers <irogers@google.com> | 2023-08-23 21:13:21 -0700 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2023-08-24 11:02:59 -0300 |
commit | edb217ff14fb98c74373f65f8ac08b9bfe26e344 (patch) | |
tree | beb414e122cc6de8c050d481dd68bd8ab79d5955 /tools/perf/util/pmu.c | |
parent | perf pmu-events: Add pmu_events_table__find_event() (diff) | |
download | linux-edb217ff14fb98c74373f65f8ac08b9bfe26e344.tar.gz linux-edb217ff14fb98c74373f65f8ac08b9bfe26e344.tar.bz2 linux-edb217ff14fb98c74373f65f8ac08b9bfe26e344.zip |
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 <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230824041330.266337-10-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/pmu.c')
-rw-r--r-- | tools/perf/util/pmu.c | 48 |
1 files changed, 17 insertions, 31 deletions
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 9ba9ac3d3d96..263c63eabc2e 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; |