[PATCH v2 0/3] Improvements for kallsyms__parse

[PATCH v2 0/3] Improvements for kallsyms__parse

[Ian Rogers]

kallsyms__parse is called 4 times during perf record startup. Add a
benchmark to measure its performance. Transition it to using the api
io.h buffered reading, improving performance by ~8% or saving ~5% from
perf record start up time.

v2. Fix the err return value for success, error reported by
    jolsa@redhat.com. Add clean-up for hex2u64.

Ian Rogers (3):
  perf bench: add kallsyms parsing
  lib kallsyms: parse using io api
  lib kallsyms: move hex2u64 out of header

 tools/lib/api/io.h                |  3 ++
 tools/lib/symbol/kallsyms.c       | 86 ++++++++++++++-----------------
 tools/lib/symbol/kallsyms.h       |  2 -
 tools/perf/bench/Build            |  1 +
 tools/perf/bench/bench.h          |  1 +
 tools/perf/bench/kallsyms-parse.c | 75 +++++++++++++++++++++++++++
 tools/perf/builtin-bench.c        |  1 +
 tools/perf/util/symbol.c          | 14 +++++
 8 files changed, 133 insertions(+), 50 deletions(-)
 create mode 100644 tools/perf/bench/kallsyms-parse.c

-- 
2.26.2.526.g744177e7f7-goog

[PATCH v2 1/3] perf bench: add kallsyms parsing

[Ian Rogers]

Add a benchmark for kallsyms parsing. Example output:

  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 103.971 ms (+- 0.121 ms)

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/bench/Build            |  1 +
 tools/perf/bench/bench.h          |  1 +
 tools/perf/bench/kallsyms-parse.c | 75 +++++++++++++++++++++++++++++++
 tools/perf/builtin-bench.c        |  1 +
 4 files changed, 78 insertions(+)
 create mode 100644 tools/perf/bench/kallsyms-parse.c

diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 042827385c87..768e408757a0 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -9,6 +9,7 @@ perf-y += futex-lock-pi.o
 perf-y += epoll-wait.o
 perf-y += epoll-ctl.o
 perf-y += synthesize.o
+perf-y += kallsyms-parse.o
 
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 4d669c803237..61cae4966cae 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -44,6 +44,7 @@ int bench_futex_lock_pi(int argc, const char **argv);
 int bench_epoll_wait(int argc, const char **argv);
 int bench_epoll_ctl(int argc, const char **argv);
 int bench_synthesize(int argc, const char **argv);
+int bench_kallsyms_parse(int argc, const char **argv);
 
 #define BENCH_FORMAT_DEFAULT_STR	"default"
 #define BENCH_FORMAT_DEFAULT		0
diff --git a/tools/perf/bench/kallsyms-parse.c b/tools/perf/bench/kallsyms-parse.c
new file mode 100644
index 000000000000..2b0d0f980ae9
--- /dev/null
+++ b/tools/perf/bench/kallsyms-parse.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Benchmark of /proc/kallsyms parsing.
+ *
+ * Copyright 2020 Google LLC.
+ */
+#include <stdlib.h>
+#include "bench.h"
+#include "../util/stat.h"
+#include <linux/time64.h>
+#include <subcmd/parse-options.h>
+#include <symbol/kallsyms.h>
+
+static unsigned int iterations = 100;
+
+static const struct option options[] = {
+	OPT_UINTEGER('i', "iterations", &iterations,
+		"Number of iterations used to compute average"),
+	OPT_END()
+};
+
+static const char *const bench_usage[] = {
+	"perf bench internals kallsyms-parse <options>",
+	NULL
+};
+
+static int bench_process_symbol(void *arg __maybe_unused,
+				const char *name __maybe_unused,
+				char type __maybe_unused,
+				u64 start __maybe_unused)
+{
+	return 0;
+}
+
+static int do_kallsyms_parse(void)
+{
+	struct timeval start, end, diff;
+	u64 runtime_us;
+	unsigned int i;
+	double time_average, time_stddev;
+	int err;
+	struct stats time_stats;
+
+	init_stats(&time_stats);
+
+	for (i = 0; i < iterations; i++) {
+		gettimeofday(&start, NULL);
+		err = kallsyms__parse("/proc/kallsyms", NULL,
+				bench_process_symbol);
+		if (err)
+			return err;
+
+		gettimeofday(&end, NULL);
+		timersub(&end, &start, &diff);
+		runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
+		update_stats(&time_stats, runtime_us);
+	}
+
+	time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
+	time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
+	printf("  Average kallsyms__parse took: %.3f ms (+- %.3f ms)\n",
+		time_average, time_stddev);
+	return 0;
+}
+
+int bench_kallsyms_parse(int argc, const char **argv)
+{
+	argc = parse_options(argc, argv, options, bench_usage, 0);
+	if (argc) {
+		usage_with_options(bench_usage, options);
+		exit(EXIT_FAILURE);
+	}
+
+	return do_kallsyms_parse();
+}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 11c79a8d85d6..083273209c88 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -78,6 +78,7 @@ static struct bench epoll_benchmarks[] = {
 
 static struct bench internals_benchmarks[] = {
 	{ "synthesize", "Benchmark perf event synthesis",	bench_synthesize	},
+	{ "kallsyms-parse", "Benchmark kallsyms parsing",	bench_kallsyms_parse	},
 	{ NULL,		NULL,					NULL			}
 };
 
-- 
2.26.2.526.g744177e7f7-goog

[PATCH v2 2/3] lib kallsyms: parse using io api

[Ian Rogers]

Perf record will call kallsyms__parse 4 times during startup and process
megabytes of data. This changes kallsyms__parse to use the io library
rather than fgets to improve performance of the user code by over 8%.

Before:
  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 103.988 ms (+- 0.203 ms)
After:
  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 95.571 ms (+- 0.006 ms)

For a workload like:
$ perf record /bin/true
Run under 'perf record -e cycles:u -g' the time goes from:
Before
30.10%     1.67%  perf     perf                [.] kallsyms__parse
After
25.55%    20.04%  perf     perf                [.] kallsyms__parse
So a little under 5% of the start-up time is removed. A lot of what
remains is on the kernel side, but caching kallsyms within perf would
at least impact memory footprint.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/api/io.h          |  3 ++
 tools/lib/symbol/kallsyms.c | 86 ++++++++++++++++---------------------
 2 files changed, 41 insertions(+), 48 deletions(-)

diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h
index b7e55b5f8a4a..777c20f6b604 100644
--- a/tools/lib/api/io.h
+++ b/tools/lib/api/io.h
@@ -7,6 +7,9 @@
 #ifndef __API_IO__
 #define __API_IO__
 
+#include <stdlib.h>
+#include <unistd.h>
+
 struct io {
 	/* File descriptor being read/ */
 	int fd;
diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
index 1a7a9f877095..e335ac2b9e19 100644
--- a/tools/lib/symbol/kallsyms.c
+++ b/tools/lib/symbol/kallsyms.c
@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "symbol/kallsyms.h"
+#include "api/io.h"
 #include <stdio.h>
-#include <stdlib.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 u8 kallsyms2elf_type(char type)
 {
@@ -15,74 +17,62 @@ bool kallsyms__is_function(char symbol_type)
 	return symbol_type == 'T' || symbol_type == 'W';
 }
 
-/*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
-int hex2u64(const char *ptr, u64 *long_val)
+static void read_to_eol(struct io *io)
 {
-	char *p;
+	int ch;
 
-	*long_val = strtoull(ptr, &p, 16);
-
-	return p - ptr;
+	for (;;) {
+		ch = io__get_char(io);
+		if (ch < 0 || ch == '\n')
+			return;
+	}
 }
 
 int kallsyms__parse(const char *filename, void *arg,
 		    int (*process_symbol)(void *arg, const char *name,
 					  char type, u64 start))
 {
-	char *line = NULL;
-	size_t n;
-	int err = -1;
-	FILE *file = fopen(filename, "r");
-
-	if (file == NULL)
-		goto out_failure;
-
-	err = 0;
+	struct io io;
+	char bf[BUFSIZ];
+	int err;
 
-	while (!feof(file)) {
-		u64 start;
-		int line_len, len;
-		char symbol_type;
-		char *symbol_name;
+	io.fd = open(filename, O_RDONLY, 0);
 
-		line_len = getline(&line, &n, file);
-		if (line_len < 0 || !line)
-			break;
+	if (io.fd < 0)
+		return -1;
 
-		line[--line_len] = '\0'; /* \n */
+	io__init(&io, io.fd, bf, sizeof(bf));
 
-		len = hex2u64(line, &start);
+	err = 0;
+	while (!io.eof) {
+		__u64 start;
+		int ch;
+		size_t i;
+		char symbol_type;
+		char symbol_name[KSYM_NAME_LEN + 1];
 
-		/* Skip the line if we failed to parse the address. */
-		if (!len)
+		if (io__get_hex(&io, &start) != ' ') {
+			read_to_eol(&io);
 			continue;
-
-		len++;
-		if (len + 2 >= line_len)
+		}
+		symbol_type = io__get_char(&io);
+		if (io__get_char(&io) != ' ') {
+			read_to_eol(&io);
 			continue;
-
-		symbol_type = line[len];
-		len += 2;
-		symbol_name = line + len;
-		len = line_len - len;
-
-		if (len >= KSYM_NAME_LEN) {
-			err = -1;
-			break;
 		}
+		for (i = 0; i < sizeof(symbol_name); i++) {
+			ch = io__get_char(&io);
+			if (ch < 0 || ch == '\n')
+				break;
+			symbol_name[i]  = ch;
+		}
+		symbol_name[i]  = '\0';
 
 		err = process_symbol(arg, symbol_name, symbol_type, start);
 		if (err)
 			break;
 	}
 
-	free(line);
-	fclose(file);
+	close(io.fd);
 	return err;
-
-out_failure:
-	return -1;
 }
-- 
2.26.2.526.g744177e7f7-goog

[PATCH v2 3/3] lib kallsyms: move hex2u64 out of header

[Ian Rogers]

hex2u64 is a helper that's out of place in kallsyms.h as not being kallsyms
related. Move from kallsyms.h to the only user.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/symbol/kallsyms.h |  2 --
 tools/perf/util/symbol.c    | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/tools/lib/symbol/kallsyms.h b/tools/lib/symbol/kallsyms.h
index bd988f7b18d4..72ab9870454b 100644
--- a/tools/lib/symbol/kallsyms.h
+++ b/tools/lib/symbol/kallsyms.h
@@ -18,8 +18,6 @@ static inline u8 kallsyms2elf_binding(char type)
 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 }
 
-int hex2u64(const char *ptr, u64 *long_val);
-
 u8 kallsyms2elf_type(char type);
 
 bool kallsyms__is_function(char symbol_type);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8f4300492dc7..381da6b39f89 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -566,6 +566,20 @@ void dso__sort_by_name(struct dso *dso)
 	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
 }
 
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+static int hex2u64(const char *ptr, u64 *long_val)
+{
+	char *p;
+
+	*long_val = strtoull(ptr, &p, 16);
+
+	return p - ptr;
+}
+
+
 int modules__parse(const char *filename, void *arg,
 		   int (*process_module)(void *arg, const char *name,
 					 u64 start, u64 size))
-- 
2.26.2.526.g744177e7f7-goog

Re: [PATCH v2 2/3] lib kallsyms: parse using io api

[Arnaldo Carvalho de Melo]

Em Fri, May 01, 2020 at 03:13:14PM -0700, Ian Rogers escreveu:
> Perf record will call kallsyms__parse 4 times during startup and process
> megabytes of data. This changes kallsyms__parse to use the io library
> rather than fgets to improve performance of the user code by over 8%.
> 
> Before:
>   Running 'internals/kallsyms-parse' benchmark:
>   Average kallsyms__parse took: 103.988 ms (+- 0.203 ms)
> After:
>   Running 'internals/kallsyms-parse' benchmark:
>   Average kallsyms__parse took: 95.571 ms (+- 0.006 ms)
> 
> For a workload like:
> $ perf record /bin/true
> Run under 'perf record -e cycles:u -g' the time goes from:
> Before
> 30.10%     1.67%  perf     perf                [.] kallsyms__parse
> After
> 25.55%    20.04%  perf     perf                [.] kallsyms__parse
> So a little under 5% of the start-up time is removed. A lot of what
> remains is on the kernel side, but caching kallsyms within perf would
> at least impact memory footprint.

Applied and added this to the commit log:

Committer notes:

The internal/kallsyms-parse bench is run using:

  [root@five ~]# perf bench internals kallsyms-parse
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 80.381 ms (+- 0.115 ms)
  [root@five ~]#

And this pre-existing test uses these routines to parse kallsyms and
then compare with the info obtained from the matching ELF symtab:

  [root@five ~]# perf test vmlinux
   1: vmlinux symtab matches kallsyms                       : Ok
  [root@five ~]#

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/lib/api/io.h          |  3 ++
>  tools/lib/symbol/kallsyms.c | 86 ++++++++++++++++---------------------
>  2 files changed, 41 insertions(+), 48 deletions(-)
> 
> diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h
> index b7e55b5f8a4a..777c20f6b604 100644
> --- a/tools/lib/api/io.h
> +++ b/tools/lib/api/io.h
> @@ -7,6 +7,9 @@
>  #ifndef __API_IO__
>  #define __API_IO__
>  
> +#include <stdlib.h>
> +#include <unistd.h>
> +
>  struct io {
>  	/* File descriptor being read/ */
>  	int fd;
> diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
> index 1a7a9f877095..e335ac2b9e19 100644
> --- a/tools/lib/symbol/kallsyms.c
> +++ b/tools/lib/symbol/kallsyms.c
> @@ -1,7 +1,9 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include "symbol/kallsyms.h"
> +#include "api/io.h"
>  #include <stdio.h>
> -#include <stdlib.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
>  
>  u8 kallsyms2elf_type(char type)
>  {
> @@ -15,74 +17,62 @@ bool kallsyms__is_function(char symbol_type)
>  	return symbol_type == 'T' || symbol_type == 'W';
>  }
>  
> -/*
> - * While we find nice hex chars, build a long_val.
> - * Return number of chars processed.
> - */
> -int hex2u64(const char *ptr, u64 *long_val)
> +static void read_to_eol(struct io *io)
>  {
> -	char *p;
> +	int ch;
>  
> -	*long_val = strtoull(ptr, &p, 16);
> -
> -	return p - ptr;
> +	for (;;) {
> +		ch = io__get_char(io);
> +		if (ch < 0 || ch == '\n')
> +			return;
> +	}
>  }
>  
>  int kallsyms__parse(const char *filename, void *arg,
>  		    int (*process_symbol)(void *arg, const char *name,
>  					  char type, u64 start))
>  {
> -	char *line = NULL;
> -	size_t n;
> -	int err = -1;
> -	FILE *file = fopen(filename, "r");
> -
> -	if (file == NULL)
> -		goto out_failure;
> -
> -	err = 0;
> +	struct io io;
> +	char bf[BUFSIZ];
> +	int err;
>  
> -	while (!feof(file)) {
> -		u64 start;
> -		int line_len, len;
> -		char symbol_type;
> -		char *symbol_name;
> +	io.fd = open(filename, O_RDONLY, 0);
>  
> -		line_len = getline(&line, &n, file);
> -		if (line_len < 0 || !line)
> -			break;
> +	if (io.fd < 0)
> +		return -1;
>  
> -		line[--line_len] = '\0'; /* \n */
> +	io__init(&io, io.fd, bf, sizeof(bf));
>  
> -		len = hex2u64(line, &start);
> +	err = 0;
> +	while (!io.eof) {
> +		__u64 start;
> +		int ch;
> +		size_t i;
> +		char symbol_type;
> +		char symbol_name[KSYM_NAME_LEN + 1];
>  
> -		/* Skip the line if we failed to parse the address. */
> -		if (!len)
> +		if (io__get_hex(&io, &start) != ' ') {
> +			read_to_eol(&io);
>  			continue;
> -
> -		len++;
> -		if (len + 2 >= line_len)
> +		}
> +		symbol_type = io__get_char(&io);
> +		if (io__get_char(&io) != ' ') {
> +			read_to_eol(&io);
>  			continue;
> -
> -		symbol_type = line[len];
> -		len += 2;
> -		symbol_name = line + len;
> -		len = line_len - len;
> -
> -		if (len >= KSYM_NAME_LEN) {
> -			err = -1;
> -			break;
>  		}
> +		for (i = 0; i < sizeof(symbol_name); i++) {
> +			ch = io__get_char(&io);
> +			if (ch < 0 || ch == '\n')
> +				break;
> +			symbol_name[i]  = ch;
> +		}
> +		symbol_name[i]  = '\0';
>  
>  		err = process_symbol(arg, symbol_name, symbol_type, start);
>  		if (err)
>  			break;
>  	}
>  
> -	free(line);
> -	fclose(file);
> +	close(io.fd);
>  	return err;
> -
> -out_failure:
> -	return -1;
>  }
> -- 
> 2.26.2.526.g744177e7f7-goog
> 

-- 

- Arnaldo

Re: [PATCH v2 0/3] Improvements for kallsyms__parse

[Arnaldo Carvalho de Melo]

Em Fri, May 01, 2020 at 03:13:12PM -0700, Ian Rogers escreveu:
> kallsyms__parse is called 4 times during perf record startup. Add a
> benchmark to measure its performance. Transition it to using the api
> io.h buffered reading, improving performance by ~8% or saving ~5% from
> perf record start up time.
> 
> v2. Fix the err return value for success, error reported by
>     jolsa@redhat.com. Add clean-up for hex2u64.

Thanks, applied. Jiri, please let me know if I can stick your Acked-by
or, better, Reviewed-by there, Namhyung, others, please consider doing
the same :-)

- Arnaldo
 
> Ian Rogers (3):
>   perf bench: add kallsyms parsing
>   lib kallsyms: parse using io api
>   lib kallsyms: move hex2u64 out of header
> 
>  tools/lib/api/io.h                |  3 ++
>  tools/lib/symbol/kallsyms.c       | 86 ++++++++++++++-----------------
>  tools/lib/symbol/kallsyms.h       |  2 -
>  tools/perf/bench/Build            |  1 +
>  tools/perf/bench/bench.h          |  1 +
>  tools/perf/bench/kallsyms-parse.c | 75 +++++++++++++++++++++++++++
>  tools/perf/builtin-bench.c        |  1 +
>  tools/perf/util/symbol.c          | 14 +++++
>  8 files changed, 133 insertions(+), 50 deletions(-)
>  create mode 100644 tools/perf/bench/kallsyms-parse.c
> 
> -- 
> 2.26.2.526.g744177e7f7-goog
> 

-- 

- Arnaldo

Re: [PATCH v2 2/3] lib kallsyms: parse using io api

[Jiri Olsa]

On Fri, May 01, 2020 at 03:13:14PM -0700, Ian Rogers wrote:

SNIP

> diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
> index 1a7a9f877095..e335ac2b9e19 100644
> --- a/tools/lib/symbol/kallsyms.c
> +++ b/tools/lib/symbol/kallsyms.c
> @@ -1,7 +1,9 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include "symbol/kallsyms.h"
> +#include "api/io.h"
>  #include <stdio.h>
> -#include <stdlib.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
>  
>  u8 kallsyms2elf_type(char type)
>  {
> @@ -15,74 +17,62 @@ bool kallsyms__is_function(char symbol_type)
>  	return symbol_type == 'T' || symbol_type == 'W';
>  }
>  
> -/*
> - * While we find nice hex chars, build a long_val.
> - * Return number of chars processed.
> - */
> -int hex2u64(const char *ptr, u64 *long_val)

hi,
when you remove in here hex2u64, you'll break the compile:

	  LINK     perf
	/usr/bin/ld: perf-in.o: in function `modules__parse':
	/home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
	/usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
	/usr/bin/ld: perf-in.o: in function `dso__load_perf_map':
	/home/jolsa/linux-perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64'
	/usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64'
	collect2: error: ld returned 1 exit status
	make[2]: *** [Makefile.perf:629: perf] Error 1
	make[1]: *** [Makefile.perf:225: sub-make] Error 2
	make: *** [Makefile:70: all] Error 2

that hex2u64 move needs to come before this change

jirka

Re: [PATCH v2 2/3] lib kallsyms: parse using io api

[Ian Rogers]

On Tue, May 5, 2020 at 7:25 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Fri, May 01, 2020 at 03:13:14PM -0700, Ian Rogers wrote:
>
> SNIP
>
> > diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
> > index 1a7a9f877095..e335ac2b9e19 100644
> > --- a/tools/lib/symbol/kallsyms.c
> > +++ b/tools/lib/symbol/kallsyms.c
> > @@ -1,7 +1,9 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  #include "symbol/kallsyms.h"
> > +#include "api/io.h"
> >  #include <stdio.h>
> > -#include <stdlib.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> >
> >  u8 kallsyms2elf_type(char type)
> >  {
> > @@ -15,74 +17,62 @@ bool kallsyms__is_function(char symbol_type)
> >       return symbol_type == 'T' || symbol_type == 'W';
> >  }
> >
> > -/*
> > - * While we find nice hex chars, build a long_val.
> > - * Return number of chars processed.
> > - */
> > -int hex2u64(const char *ptr, u64 *long_val)
>
> hi,
> when you remove in here hex2u64, you'll break the compile:
>
>           LINK     perf
>         /usr/bin/ld: perf-in.o: in function `modules__parse':
>         /home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
>         /usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
>         /usr/bin/ld: perf-in.o: in function `dso__load_perf_map':
>         /home/jolsa/linux-perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64'
>         /usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64'
>         collect2: error: ld returned 1 exit status
>         make[2]: *** [Makefile.perf:629: perf] Error 1
>         make[1]: *** [Makefile.perf:225: sub-make] Error 2
>         make: *** [Makefile:70: all] Error 2
>
> that hex2u64 move needs to come before this change

Good catch. Fixed in v3.
https://lore.kernel.org/lkml/20200505143625.147832-1-irogers@google.com/T/#t

Thanks,
Ian

> jirka
>

Re: [PATCH v2 2/3] lib kallsyms: parse using io api

[Arnaldo Carvalho de Melo]

Em Tue, May 05, 2020 at 04:25:21PM +0200, Jiri Olsa escreveu:
> On Fri, May 01, 2020 at 03:13:14PM -0700, Ian Rogers wrote:
> 
> SNIP
> 
> > diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
> > index 1a7a9f877095..e335ac2b9e19 100644
> > --- a/tools/lib/symbol/kallsyms.c
> > +++ b/tools/lib/symbol/kallsyms.c
> > @@ -1,7 +1,9 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  #include "symbol/kallsyms.h"
> > +#include "api/io.h"
> >  #include <stdio.h>
> > -#include <stdlib.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> >  
> >  u8 kallsyms2elf_type(char type)
> >  {
> > @@ -15,74 +17,62 @@ bool kallsyms__is_function(char symbol_type)
> >  	return symbol_type == 'T' || symbol_type == 'W';
> >  }
> >  
> > -/*
> > - * While we find nice hex chars, build a long_val.
> > - * Return number of chars processed.
> > - */
> > -int hex2u64(const char *ptr, u64 *long_val)
> 
> hi,
> when you remove in here hex2u64, you'll break the compile:
> 
> 	  LINK     perf
> 	/usr/bin/ld: perf-in.o: in function `modules__parse':
> 	/home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
> 	/usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
> 	/usr/bin/ld: perf-in.o: in function `dso__load_perf_map':
> 	/home/jolsa/linux-perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64'
> 	/usr/bin/ld: /home/jolsa/linux-perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64'
> 	collect2: error: ld returned 1 exit status
> 	make[2]: *** [Makefile.perf:629: perf] Error 1
> 	make[1]: *** [Makefile.perf:225: sub-make] Error 2
> 	make: *** [Makefile:70: all] Error 2
> 
> that hex2u64 move needs to come before this change

I noticed this and fixed it all, was about to send this note I've added:

---------------

Also we can't remove hex2u64() in this patch as this breaks the build:

  /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `modules__parse':
  /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
  /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
  /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `dso__load_perf_map':
  /home/acme/git/perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64'
  /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64'
  collect2: error: ld returned 1 exit status

Leave it there, move it in the next patch.

[tip: perf/core] libsymbols kallsyms: Move hex2u64 out of header

[tip-bot2 for Ian Rogers]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     32add10f9597f2e4e46fa8342a83ae7bdfefd1ae
Gitweb:        https://git.kernel.org/tip/32add10f9597f2e4e46fa8342a83ae7bdfefd1ae
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Fri, 01 May 2020 15:13:15 -07:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Tue, 05 May 2020 16:35:32 -03:00

libsymbols kallsyms: Move hex2u64 out of header

hex2u64 is a helper that's out of place in kallsyms.h as not being
kallsyms related. Move from kallsyms.h to the only user.

Committer notes:

Move it out of tools/lib/symbol/kallsyms.c as well, as we had to leave
it there in the previous patch lest we break the build.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200501221315.54715-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/symbol/kallsyms.c | 13 -------------
 tools/lib/symbol/kallsyms.h |  2 --
 tools/perf/util/symbol.c    | 14 ++++++++++++++
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
index a5edc75..e335ac2 100644
--- a/tools/lib/symbol/kallsyms.c
+++ b/tools/lib/symbol/kallsyms.c
@@ -11,19 +11,6 @@ u8 kallsyms2elf_type(char type)
 	return (type == 't' || type == 'w') ? STT_FUNC : STT_OBJECT;
 }
 
-/*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
-int hex2u64(const char *ptr, u64 *long_val)
-{
-	char *p;
-
-	*long_val = strtoull(ptr, &p, 16);
-
-	return p - ptr;
-}
-
 bool kallsyms__is_function(char symbol_type)
 {
 	symbol_type = toupper(symbol_type);
diff --git a/tools/lib/symbol/kallsyms.h b/tools/lib/symbol/kallsyms.h
index bd988f7..72ab987 100644
--- a/tools/lib/symbol/kallsyms.h
+++ b/tools/lib/symbol/kallsyms.h
@@ -18,8 +18,6 @@ static inline u8 kallsyms2elf_binding(char type)
 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 }
 
-int hex2u64(const char *ptr, u64 *long_val);
-
 u8 kallsyms2elf_type(char type);
 
 bool kallsyms__is_function(char symbol_type);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8f43004..381da6b 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -566,6 +566,20 @@ void dso__sort_by_name(struct dso *dso)
 	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
 }
 
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+static int hex2u64(const char *ptr, u64 *long_val)
+{
+	char *p;
+
+	*long_val = strtoull(ptr, &p, 16);
+
+	return p - ptr;
+}
+
+
 int modules__parse(const char *filename, void *arg,
 		   int (*process_module)(void *arg, const char *name,
 					 u64 start, u64 size))

[tip: perf/core] libsymbols kallsyms: Parse using io api

[tip-bot2 for Ian Rogers]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     53df2b93441289848f5c2e76d19d1569816b2b9d
Gitweb:        https://git.kernel.org/tip/53df2b93441289848f5c2e76d19d1569816b2b9d
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Fri, 01 May 2020 15:13:14 -07:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Tue, 05 May 2020 16:35:32 -03:00

libsymbols kallsyms: Parse using io api

'perf record' will call kallsyms__parse 4 times during startup and
process megabytes of data. This changes kallsyms__parse to use the io
library rather than fgets to improve performance of the user code by
over 8%.

Before:

  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 103.988 ms (+- 0.203 ms)

After:

  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 95.571 ms (+- 0.006 ms)

For a workload like:

  $ perf record /bin/true
  Run under 'perf record -e cycles:u -g' the time goes from:
  Before
  30.10%     1.67%  perf     perf                [.] kallsyms__parse
  After
  25.55%    20.04%  perf     perf                [.] kallsyms__parse

So a little under 5% of the start-up time is removed. A lot of what
remains is on the kernel side, but caching kallsyms within perf would at
least impact memory footprint.

Committer notes:

The internal/kallsyms-parse bench is run using:

  [root@five ~]# perf bench internals kallsyms-parse
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 80.381 ms (+- 0.115 ms)
  [root@five ~]#

And this pre-existing test uses these routines to parse kallsyms and
then compare with the info obtained from the matching ELF symtab:

  [root@five ~]# perf test vmlinux
   1: vmlinux symtab matches kallsyms                       : Ok
  [root@five ~]#

Also we can't remove hex2u64() in this patch as this breaks the build:

  /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `modules__parse':
  /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
  /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64'
  /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `dso__load_perf_map':
  /home/acme/git/perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64'
  /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64'
  collect2: error: ld returned 1 exit status

Leave it there, move it in the next patch.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200501221315.54715-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/api/io.h          |  3 +-
 tools/lib/symbol/kallsyms.c | 93 ++++++++++++++++++------------------
 2 files changed, 51 insertions(+), 45 deletions(-)

diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h
index b7e55b5..777c20f 100644
--- a/tools/lib/api/io.h
+++ b/tools/lib/api/io.h
@@ -7,6 +7,9 @@
 #ifndef __API_IO__
 #define __API_IO__
 
+#include <stdlib.h>
+#include <unistd.h>
+
 struct io {
 	/* File descriptor being read/ */
 	int fd;
diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
index 1a7a9f8..a5edc75 100644
--- a/tools/lib/symbol/kallsyms.c
+++ b/tools/lib/symbol/kallsyms.c
@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "symbol/kallsyms.h"
+#include "api/io.h"
 #include <stdio.h>
-#include <stdlib.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 u8 kallsyms2elf_type(char type)
 {
@@ -9,12 +11,6 @@ u8 kallsyms2elf_type(char type)
 	return (type == 't' || type == 'w') ? STT_FUNC : STT_OBJECT;
 }
 
-bool kallsyms__is_function(char symbol_type)
-{
-	symbol_type = toupper(symbol_type);
-	return symbol_type == 'T' || symbol_type == 'W';
-}
-
 /*
  * While we find nice hex chars, build a long_val.
  * Return number of chars processed.
@@ -28,61 +24,68 @@ int hex2u64(const char *ptr, u64 *long_val)
 	return p - ptr;
 }
 
+bool kallsyms__is_function(char symbol_type)
+{
+	symbol_type = toupper(symbol_type);
+	return symbol_type == 'T' || symbol_type == 'W';
+}
+
+static void read_to_eol(struct io *io)
+{
+	int ch;
+
+	for (;;) {
+		ch = io__get_char(io);
+		if (ch < 0 || ch == '\n')
+			return;
+	}
+}
+
 int kallsyms__parse(const char *filename, void *arg,
 		    int (*process_symbol)(void *arg, const char *name,
 					  char type, u64 start))
 {
-	char *line = NULL;
-	size_t n;
-	int err = -1;
-	FILE *file = fopen(filename, "r");
-
-	if (file == NULL)
-		goto out_failure;
-
-	err = 0;
+	struct io io;
+	char bf[BUFSIZ];
+	int err;
 
-	while (!feof(file)) {
-		u64 start;
-		int line_len, len;
-		char symbol_type;
-		char *symbol_name;
+	io.fd = open(filename, O_RDONLY, 0);
 
-		line_len = getline(&line, &n, file);
-		if (line_len < 0 || !line)
-			break;
+	if (io.fd < 0)
+		return -1;
 
-		line[--line_len] = '\0'; /* \n */
+	io__init(&io, io.fd, bf, sizeof(bf));
 
-		len = hex2u64(line, &start);
+	err = 0;
+	while (!io.eof) {
+		__u64 start;
+		int ch;
+		size_t i;
+		char symbol_type;
+		char symbol_name[KSYM_NAME_LEN + 1];
 
-		/* Skip the line if we failed to parse the address. */
-		if (!len)
+		if (io__get_hex(&io, &start) != ' ') {
+			read_to_eol(&io);
 			continue;
-
-		len++;
-		if (len + 2 >= line_len)
+		}
+		symbol_type = io__get_char(&io);
+		if (io__get_char(&io) != ' ') {
+			read_to_eol(&io);
 			continue;
-
-		symbol_type = line[len];
-		len += 2;
-		symbol_name = line + len;
-		len = line_len - len;
-
-		if (len >= KSYM_NAME_LEN) {
-			err = -1;
-			break;
 		}
+		for (i = 0; i < sizeof(symbol_name); i++) {
+			ch = io__get_char(&io);
+			if (ch < 0 || ch == '\n')
+				break;
+			symbol_name[i]  = ch;
+		}
+		symbol_name[i]  = '\0';
 
 		err = process_symbol(arg, symbol_name, symbol_type, start);
 		if (err)
 			break;
 	}
 
-	free(line);
-	fclose(file);
+	close(io.fd);
 	return err;
-
-out_failure:
-	return -1;
 }

[tip: perf/core] perf bench: Add kallsyms parsing

[tip-bot2 for Ian Rogers]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     51876bd45263f62083bbb823220bfb48909f313a
Gitweb:        https://git.kernel.org/tip/51876bd45263f62083bbb823220bfb48909f313a
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Fri, 01 May 2020 15:13:13 -07:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Tue, 05 May 2020 16:35:32 -03:00

perf bench: Add kallsyms parsing

Add a benchmark for kallsyms parsing. Example output:

  Running 'internals/kallsyms-parse' benchmark:
  Average kallsyms__parse took: 103.971 ms (+- 0.121 ms)

Committer testing:

Test Machine: AMD Ryzen 5 3600X 6-Core Processor

  [root@five ~]# perf bench internals kallsyms-parse
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 79.692 ms (+- 0.101 ms)
  [root@five ~]# perf stat -r5 perf bench internals kallsyms-parse
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 80.563 ms (+- 0.079 ms)
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 81.046 ms (+- 0.155 ms)
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 80.874 ms (+- 0.104 ms)
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 81.173 ms (+- 0.133 ms)
  # Running 'internals/kallsyms-parse' benchmark:
    Average kallsyms__parse took: 81.169 ms (+- 0.074 ms)

   Performance counter stats for 'perf bench internals kallsyms-parse' (5 runs):

            8,093.54 msec task-clock                #    0.999 CPUs utilized            ( +-  0.14% )
               3,165      context-switches          #    0.391 K/sec                    ( +-  0.18% )
                  10      cpu-migrations            #    0.001 K/sec                    ( +- 23.13% )
                 744      page-faults               #    0.092 K/sec                    ( +-  0.21% )
      34,551,564,954      cycles                    #    4.269 GHz                      ( +-  0.05% )  (83.33%)
       1,160,584,308      stalled-cycles-frontend   #    3.36% frontend cycles idle     ( +-  1.60% )  (83.33%)
      14,974,323,985      stalled-cycles-backend    #   43.34% backend cycles idle      ( +-  0.24% )  (83.33%)
      58,712,905,705      instructions              #    1.70  insn per cycle
                                                    #    0.26  stalled cycles per insn  ( +-  0.01% )  (83.34%)
      14,136,433,778      branches                  # 1746.632 M/sec                    ( +-  0.01% )  (83.33%)
         141,943,217      branch-misses             #    1.00% of all branches          ( +-  0.04% )  (83.33%)

              8.1040 +- 0.0115 seconds time elapsed  ( +-  0.14% )

  [root@five ~]#

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200501221315.54715-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/bench/Build            |  1 +-
 tools/perf/bench/bench.h          |  1 +-
 tools/perf/bench/kallsyms-parse.c | 75 ++++++++++++++++++++++++++++++-
 tools/perf/builtin-bench.c        |  1 +-
 4 files changed, 78 insertions(+)
 create mode 100644 tools/perf/bench/kallsyms-parse.c

diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 0428273..768e408 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -9,6 +9,7 @@ perf-y += futex-lock-pi.o
 perf-y += epoll-wait.o
 perf-y += epoll-ctl.o
 perf-y += synthesize.o
+perf-y += kallsyms-parse.o
 
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
 perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 4d669c8..61cae49 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -44,6 +44,7 @@ int bench_futex_lock_pi(int argc, const char **argv);
 int bench_epoll_wait(int argc, const char **argv);
 int bench_epoll_ctl(int argc, const char **argv);
 int bench_synthesize(int argc, const char **argv);
+int bench_kallsyms_parse(int argc, const char **argv);
 
 #define BENCH_FORMAT_DEFAULT_STR	"default"
 #define BENCH_FORMAT_DEFAULT		0
diff --git a/tools/perf/bench/kallsyms-parse.c b/tools/perf/bench/kallsyms-parse.c
new file mode 100644
index 0000000..2b0d0f9
--- /dev/null
+++ b/tools/perf/bench/kallsyms-parse.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Benchmark of /proc/kallsyms parsing.
+ *
+ * Copyright 2020 Google LLC.
+ */
+#include <stdlib.h>
+#include "bench.h"
+#include "../util/stat.h"
+#include <linux/time64.h>
+#include <subcmd/parse-options.h>
+#include <symbol/kallsyms.h>
+
+static unsigned int iterations = 100;
+
+static const struct option options[] = {
+	OPT_UINTEGER('i', "iterations", &iterations,
+		"Number of iterations used to compute average"),
+	OPT_END()
+};
+
+static const char *const bench_usage[] = {
+	"perf bench internals kallsyms-parse <options>",
+	NULL
+};
+
+static int bench_process_symbol(void *arg __maybe_unused,
+				const char *name __maybe_unused,
+				char type __maybe_unused,
+				u64 start __maybe_unused)
+{
+	return 0;
+}
+
+static int do_kallsyms_parse(void)
+{
+	struct timeval start, end, diff;
+	u64 runtime_us;
+	unsigned int i;
+	double time_average, time_stddev;
+	int err;
+	struct stats time_stats;
+
+	init_stats(&time_stats);
+
+	for (i = 0; i < iterations; i++) {
+		gettimeofday(&start, NULL);
+		err = kallsyms__parse("/proc/kallsyms", NULL,
+				bench_process_symbol);
+		if (err)
+			return err;
+
+		gettimeofday(&end, NULL);
+		timersub(&end, &start, &diff);
+		runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
+		update_stats(&time_stats, runtime_us);
+	}
+
+	time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
+	time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
+	printf("  Average kallsyms__parse took: %.3f ms (+- %.3f ms)\n",
+		time_average, time_stddev);
+	return 0;
+}
+
+int bench_kallsyms_parse(int argc, const char **argv)
+{
+	argc = parse_options(argc, argv, options, bench_usage, 0);
+	if (argc) {
+		usage_with_options(bench_usage, options);
+		exit(EXIT_FAILURE);
+	}
+
+	return do_kallsyms_parse();
+}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 11c79a8..0832732 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -78,6 +78,7 @@ static struct bench epoll_benchmarks[] = {
 
 static struct bench internals_benchmarks[] = {
 	{ "synthesize", "Benchmark perf event synthesis",	bench_synthesize	},
+	{ "kallsyms-parse", "Benchmark kallsyms parsing",	bench_kallsyms_parse	},
 	{ NULL,		NULL,					NULL			}
 };