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Message-Id: <20230824041330.266337-10-irogers@google.com>
Date: Wed, 23 Aug 2023 21:13:21 -0700
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>,
Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
James Clark <james.clark@....com>,
Kan Liang <kan.liang@...ux.intel.com>,
John Garry <john.g.garry@...cle.com>,
Kajol Jain <kjain@...ux.ibm.com>,
Jing Zhang <renyu.zj@...ux.alibaba.com>,
Ravi Bangoria <ravi.bangoria@....com>,
Rob Herring <robh@...nel.org>,
Gaosheng Cui <cuigaosheng1@...wei.com>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 09/18] 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@...gle.com>
---
tools/perf/arch/x86/util/intel-pt.c | 2 +-
tools/perf/tests/parse-events.c | 2 +-
tools/perf/util/parse-events.c | 18 +++++++----
tools/perf/util/parse-events.h | 3 +-
tools/perf/util/pmu.c | 48 ++++++++++-------------------
5 files changed, 33 insertions(+), 40 deletions(-)
diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index 27944c15ac14..31807791589e 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 658fb9599d95..d86076d575ed 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 781747bedc3e..c71e135d7335 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 411f69b2ac3a..c7f779420723 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -9,6 +9,7 @@
#include <stdbool.h>
#include <linux/types.h>
#include <linux/perf_event.h>
+#include <stdio.h>
#include <string.h>
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 9ba9ac3d3d96..263c63eabc2e 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -280,7 +280,7 @@ int perf_pmu__convert_scale(const char *scale, char **end, double *sval)
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 @@ static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, int dirfd, char *
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 @@ static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, int dirfd, char *n
}
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;
--
2.42.0.rc1.204.g551eb34607-goog
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