Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
authored by
Ian Rogers
and committed by
Arnaldo Carvalho de Melo
edb217ff
3d504549
+33
-40
+1
-1
tools/perf/arch/x86/util/intel-pt.c
+1
-1
tools/perf/arch/x86/util/intel-pt.c
+1
-1
tools/perf/tests/parse-events.c
+1
-1
tools/perf/tests/parse-events.c
+12
-6
tools/perf/util/parse-events.c
+12
-6
tools/perf/util/parse-events.c
···
1715
1715
}
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static int parse_events__scanner(const char *str,
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+
FILE *input,
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struct parse_events_state *parse_state)
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{
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YY_BUFFER_STATE buffer;
···
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if (ret)
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return ret;
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-
buffer = parse_events__scan_string(str, scanner);
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+
if (str)
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+
buffer = parse_events__scan_string(str, scanner);
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+
else
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parse_events_set_in(input, scanner);
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#ifdef PARSER_DEBUG
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parse_events_debug = 1;
···
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#endif
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ret = parse_events_parse(parse_state, scanner);
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-
parse_events__flush_buffer(buffer, scanner);
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-
parse_events__delete_buffer(buffer, scanner);
1736
+
if (str) {
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+
parse_events__flush_buffer(buffer, scanner);
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+
parse_events__delete_buffer(buffer, scanner);
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+
}
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parse_events_lex_destroy(scanner);
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return ret;
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}
···
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1742
/*
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* parse event config string, return a list of event terms.
1750
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*/
1751
-
int parse_events_terms(struct list_head *terms, const char *str)
1745
+
int parse_events_terms(struct list_head *terms, const char *str, FILE *input)
1752
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{
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struct parse_events_state parse_state = {
1754
1748
.terms = NULL,
···
1756
1750
};
1757
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int ret;
1758
1752
1759
-
ret = parse_events__scanner(str, &parse_state);
1753
+
ret = parse_events__scanner(str, input, &parse_state);
1760
1754
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if (!ret) {
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list_splice(parse_state.terms, terms);
···
2007
2001
};
2008
2002
int ret, ret2;
2009
2003
2010
-
ret = parse_events__scanner(str, &parse_state);
2004
+
ret = parse_events__scanner(str, /*input=*/ NULL, &parse_state);
2011
2005
2012
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if (!ret && list_empty(&parse_state.list)) {
2013
2007
WARN_ONCE(true, "WARNING: event parser found nothing\n");
+2
-1
tools/perf/util/parse-events.h
+2
-1
tools/perf/util/parse-events.h
···
9
9
#include <stdbool.h>
10
10
#include <linux/types.h>
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11
#include <linux/perf_event.h>
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+
#include <stdio.h>
12
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#include <string.h>
13
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struct evsel;
···
43
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44
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int parse_event(struct evlist *evlist, const char *str);
45
44
46
-
int parse_events_terms(struct list_head *terms, const char *str);
45
+
int parse_events_terms(struct list_head *terms, const char *str, FILE *input);
47
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int parse_filter(const struct option *opt, const char *str, int unset);
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int exclude_perf(const struct option *opt, const char *arg, int unset);
49
48
+17
-31
tools/perf/util/pmu.c
+17
-31
tools/perf/util/pmu.c
···
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return ret;
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}
282
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-
static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, int dirfd, char *name)
283
+
static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, int dirfd, const char *name)
284
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{
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struct stat st;
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ssize_t sret;
···
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return ret;
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}
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-
static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, int dirfd, char *name)
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+
static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, int dirfd, const char *name)
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{
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char path[PATH_MAX];
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ssize_t sret;
···
343
343
}
344
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345
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static int
346
-
perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, int dirfd, char *name)
346
+
perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, int dirfd, const char *name)
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347
{
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char path[PATH_MAX];
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int fd;
···
361
361
}
362
362
363
363
static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
364
-
int dirfd, char *name)
364
+
int dirfd, const char *name)
365
365
{
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char path[PATH_MAX];
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int fd;
···
454
454
return false;
455
455
}
456
456
457
-
static int __perf_pmu__new_alias(struct list_head *list, int dirfd, char *name,
458
-
char *desc, char *val, const struct pmu_event *pe)
457
+
static int perf_pmu__new_alias(struct list_head *list, int dirfd, const char *name,
458
+
const char *desc, const char *val, FILE *val_fd,
459
+
const struct pmu_event *pe)
459
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{
460
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struct parse_events_term *term;
461
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struct perf_pmu_alias *alias;
···
485
484
alias->snapshot = false;
486
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alias->deprecated = deprecated;
487
486
488
-
ret = parse_events_terms(&alias->terms, val);
487
+
ret = parse_events_terms(&alias->terms, val, val_fd);
489
488
if (ret) {
490
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pr_err("Cannot parse alias %s: %d\n", val, ret);
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free(alias);
···
540
539
list_add_tail(&alias->list, list);
541
540
542
541
return 0;
543
-
}
544
-
545
-
static int perf_pmu__new_alias(struct list_head *list, int dirfd, char *name, FILE *file)
546
-
{
547
-
char buf[256];
548
-
int ret;
549
-
550
-
ret = fread(buf, 1, sizeof(buf), file);
551
-
if (ret == 0)
552
-
return -EINVAL;
553
-
554
-
buf[ret] = 0;
555
-
556
-
/* Remove trailing newline from sysfs file */
557
-
strim(buf);
558
-
559
-
return __perf_pmu__new_alias(list, dirfd, name, NULL, buf, NULL);
560
542
}
561
543
562
544
static inline bool pmu_alias_info_file(char *name)
···
597
613
continue;
598
614
}
599
615
600
-
if (perf_pmu__new_alias(head, dirfd, name, file) < 0)
616
+
if (perf_pmu__new_alias(head, dirfd, name, /*desc=*/ NULL,
617
+
/*val=*/ NULL, file, /*pe=*/ NULL) < 0)
601
618
pr_debug("Cannot set up %s\n", name);
602
619
fclose(file);
603
620
}
···
851
866
struct list_head *head = vdata;
852
867
853
868
/* need type casts to override 'const' */
854
-
__perf_pmu__new_alias(head, -1, (char *)pe->name, (char *)pe->desc, (char *)pe->event, pe);
869
+
perf_pmu__new_alias(head, -1, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL, pe);
855
870
return 0;
856
871
}
857
872
···
892
907
893
908
if (!strcmp(pmu->id, pe->compat) &&
894
909
pmu_uncore_alias_match(pe->pmu, pmu->name)) {
895
-
__perf_pmu__new_alias(idata->head, -1,
896
-
(char *)pe->name,
897
-
(char *)pe->desc,
898
-
(char *)pe->event,
899
-
pe);
910
+
perf_pmu__new_alias(idata->head, -1,
911
+
pe->name,
912
+
pe->desc,
913
+
pe->event,
914
+
/*val_fd=*/ NULL,
915
+
pe);
900
916
}
901
917
902
918
return 0;