[PATCH 05/35] perf time-utils: Refactor time range parsing code

From: Arnaldo Carvalho de Melo
Date: Thu Mar 07 2019 - 12:45:14 EST


From: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>

Jiri points out that we don't need any time checking and time string
parsing if the --time option is not set. That makes sense.

This patch refactors the time range parsing code, move the duplicated
code from perf report and perf script to time_utils and check if --time
option is set before parsing the time string. This patch is no logic
change expected. So the usage of --time is same as before.

For example:

Select the first and second 10% time slices:
perf report --time 10%/1,10%/2
perf script --time 10%/1,10%/2

Select the slices from 0% to 10% and from 30% to 40%:
perf report --time 0%-10%,30%-40%
perf script --time 0%-10%,30%-40%

Select the time slices from timestamp 3971 to 3973
perf report --time 3971,3973
perf script --time 3971,3973

Committer testing:

Using the above examples, check before and after to see if it remains
the same:

$ perf record -F 10000 -- find . -name "*.[ch]" -exec cat {} + > /dev/null
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 1.626 MB perf.data (42392 samples) ]
$
$ perf report --time 10%/1,10%/2 > /tmp/report.before.1
$ perf script --time 10%/1,10%/2 > /tmp/script.before.1
$ perf report --time 0%-10%,30%-40% > /tmp/report.before.2
$ perf script --time 0%-10%,30%-40% > /tmp/script.before.2
$ perf report --time 180457.375844,180457.377717 > /tmp/report.before.3
$ perf script --time 180457.375844,180457.377717 > /tmp/script.before.3

For example, the 3rd test produces this slice:

$ cat /tmp/script.before.3
cat 3147 180457.375844: 2143 cycles:uppp: 7f79362590d9 cfree@xxxxxxxxxxx+0x9 (/usr/lib64/libc-2.28.so)
cat 3147 180457.375986: 2245 cycles:uppp: 558b70f3d86e [unknown] (/usr/bin/cat)
cat 3147 180457.376012: 2164 cycles:uppp: 7f7936257430 _int_malloc+0x8c0 (/usr/lib64/libc-2.28.so)
cat 3147 180457.376140: 2921 cycles:uppp: 558b70f3a554 [unknown] (/usr/bin/cat)
cat 3147 180457.376296: 2844 cycles:uppp: 7f7936258abe malloc+0x4e (/usr/lib64/libc-2.28.so)
cat 3147 180457.376431: 2717 cycles:uppp: 558b70f3b0ca [unknown] (/usr/bin/cat)
cat 3147 180457.376667: 2630 cycles:uppp: 558b70f3d86e [unknown] (/usr/bin/cat)
cat 3147 180457.376795: 2442 cycles:uppp: 7f79362bff55 read+0x15 (/usr/lib64/libc-2.28.so)
cat 3147 180457.376927: 2376 cycles:uppp: ffffffff9aa00163 [unknown] ([unknown])
cat 3147 180457.376954: 2307 cycles:uppp: 7f7936257438 _int_malloc+0x8c8 (/usr/lib64/libc-2.28.so)
cat 3147 180457.377116: 3091 cycles:uppp: 7f7936258a70 malloc+0x0 (/usr/lib64/libc-2.28.so)
cat 3147 180457.377362: 2945 cycles:uppp: 558b70f3a3b0 [unknown] (/usr/bin/cat)
cat 3147 180457.377517: 2727 cycles:uppp: 558b70f3a9aa [unknown] (/usr/bin/cat)
$

Install 'coreutils-debuginfo' to see cat's guts (symbols), but then, the
above chunk translates into this 'perf report' output:

$ cat /tmp/report.before.3
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 13 of event 'cycles:uppp' (time slices: 180457.375844,180457.377717)
# Event count (approx.): 33552
#
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
17.69% cat libc-2.28.so [.] malloc
14.53% cat cat [.] 0x000000000000586e
13.33% cat libc-2.28.so [.] _int_malloc
8.78% cat cat [.] 0x00000000000023b0
8.71% cat cat [.] 0x0000000000002554
8.13% cat cat [.] 0x00000000000029aa
8.10% cat cat [.] 0x00000000000030ca
7.28% cat libc-2.28.so [.] read
7.08% cat [unknown] [k] 0xffffffff9aa00163
6.39% cat libc-2.28.so [.] cfree@xxxxxxxxxxx

#
# (Tip: Order by the overhead of source file name and line number: perf report -s srcline)
#
$

Now lets see after applying this patch, nothing should change:

$ perf report --time 10%/1,10%/2 > /tmp/report.after.1
$ perf script --time 10%/1,10%/2 > /tmp/script.after.1
$ perf report --time 0%-10%,30%-40% > /tmp/report.after.2
$ perf script --time 0%-10%,30%-40% > /tmp/script.after.2
$ perf report --time 180457.375844,180457.377717 > /tmp/report.after.3
$ perf script --time 180457.375844,180457.377717 > /tmp/script.after.3
$ diff -u /tmp/report.before.1 /tmp/report.after.1
$ diff -u /tmp/script.before.1 /tmp/script.after.1
$ diff -u /tmp/report.before.2 /tmp/report.after.2
--- /tmp/report.before.2 2019-03-01 11:01:53.526094883 -0300
+++ /tmp/report.after.2 2019-03-01 11:09:18.231770467 -0300
@@ -352,5 +352,5 @@

#
-# (Tip: Generate a script for your data: perf script -g <lang>)
+# (Tip: Treat branches as callchains: perf report --branch-history)
#
$ diff -u /tmp/script.before.2 /tmp/script.after.2
$ diff -u /tmp/report.before.3 /tmp/report.after.3
--- /tmp/report.before.3 2019-03-01 11:03:08.890045588 -0300
+++ /tmp/report.after.3 2019-03-01 11:09:40.660224002 -0300
@@ -22,5 +22,5 @@

#
-# (Tip: Order by the overhead of source file name and line number: perf report -s srcline)
+# (Tip: List events using substring match: perf list <keyword>)
#
$ diff -u /tmp/script.before.3 /tmp/script.after.3
$

Cool, just the 'perf report' tips changed, QED.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jin Yao <yao.jin@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1551435186-6008-1-git-send-email-yao.jin@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-report.c | 38 ++++++---------------------
tools/perf/builtin-script.c | 39 ++++++---------------------
tools/perf/util/time-utils.c | 51 +++++++++++++++++++++++++++++++++++-
tools/perf/util/time-utils.h | 6 +++++
4 files changed, 72 insertions(+), 62 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 1532ebde6c4b..ee93c18a6685 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1375,36 +1375,13 @@ int cmd_report(int argc, const char **argv)
if (symbol__init(&session->header.env) < 0)
goto error;

- report.ptime_range = perf_time__range_alloc(report.time_str,
- &report.range_size);
- if (!report.ptime_range) {
- ret = -ENOMEM;
- goto error;
- }
-
- if (perf_time__parse_str(report.ptime_range, report.time_str) != 0) {
- if (session->evlist->first_sample_time == 0 &&
- session->evlist->last_sample_time == 0) {
- pr_err("HINT: no first/last sample time found in perf data.\n"
- "Please use latest perf binary to execute 'perf record'\n"
- "(if '--buildid-all' is enabled, please set '--timestamp-boundary').\n");
- ret = -EINVAL;
- goto error;
- }
-
- report.range_num = perf_time__percent_parse_str(
- report.ptime_range, report.range_size,
- report.time_str,
- session->evlist->first_sample_time,
- session->evlist->last_sample_time);
-
- if (report.range_num < 0) {
- pr_err("Invalid time string\n");
- ret = -EINVAL;
+ if (report.time_str) {
+ ret = perf_time__parse_for_ranges(report.time_str, session,
+ &report.ptime_range,
+ &report.range_size,
+ &report.range_num);
+ if (ret < 0)
goto error;
- }
- } else {
- report.range_num = 1;
}

if (session->tevent.pevent &&
@@ -1426,7 +1403,8 @@ int cmd_report(int argc, const char **argv)
ret = 0;

error:
- zfree(&report.ptime_range);
+ if (report.ptime_range)
+ zfree(&report.ptime_range);

perf_session__delete(session);
return ret;
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 2d8cb1d1682c..53f78cf3113f 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -3699,37 +3699,13 @@ int cmd_script(int argc, const char **argv)
if (err < 0)
goto out_delete;

- script.ptime_range = perf_time__range_alloc(script.time_str,
- &script.range_size);
- if (!script.ptime_range) {
- err = -ENOMEM;
- goto out_delete;
- }
-
- /* needs to be parsed after looking up reference time */
- if (perf_time__parse_str(script.ptime_range, script.time_str) != 0) {
- if (session->evlist->first_sample_time == 0 &&
- session->evlist->last_sample_time == 0) {
- pr_err("HINT: no first/last sample time found in perf data.\n"
- "Please use latest perf binary to execute 'perf record'\n"
- "(if '--buildid-all' is enabled, please set '--timestamp-boundary').\n");
- err = -EINVAL;
- goto out_delete;
- }
-
- script.range_num = perf_time__percent_parse_str(
- script.ptime_range, script.range_size,
- script.time_str,
- session->evlist->first_sample_time,
- session->evlist->last_sample_time);
-
- if (script.range_num < 0) {
- pr_err("Invalid time string\n");
- err = -EINVAL;
+ if (script.time_str) {
+ err = perf_time__parse_for_ranges(script.time_str, session,
+ &script.ptime_range,
+ &script.range_size,
+ &script.range_num);
+ if (err < 0)
goto out_delete;
- }
- } else {
- script.range_num = 1;
}

err = __cmd_script(&script);
@@ -3737,7 +3713,8 @@ int cmd_script(int argc, const char **argv)
flush_scripting();

out_delete:
- zfree(&script.ptime_range);
+ if (script.ptime_range)
+ zfree(&script.ptime_range);

perf_evlist__free_stats(session->evlist);
perf_session__delete(session);
diff --git a/tools/perf/util/time-utils.c b/tools/perf/util/time-utils.c
index 6193b46050a5..0f53baec660e 100644
--- a/tools/perf/util/time-utils.c
+++ b/tools/perf/util/time-utils.c
@@ -11,6 +11,8 @@
#include "perf.h"
#include "debug.h"
#include "time-utils.h"
+#include "session.h"
+#include "evlist.h"

int parse_nsec_time(const char *str, u64 *ptime)
{
@@ -374,7 +376,7 @@ bool perf_time__ranges_skip_sample(struct perf_time_interval *ptime_buf,
struct perf_time_interval *ptime;
int i;

- if ((timestamp == 0) || (num == 0))
+ if ((!ptime_buf) || (timestamp == 0) || (num == 0))
return false;

if (num == 1)
@@ -396,6 +398,53 @@ bool perf_time__ranges_skip_sample(struct perf_time_interval *ptime_buf,
return (i == num) ? true : false;
}

+int perf_time__parse_for_ranges(const char *time_str,
+ struct perf_session *session,
+ struct perf_time_interval **ranges,
+ int *range_size, int *range_num)
+{
+ struct perf_time_interval *ptime_range;
+ int size, num, ret;
+
+ ptime_range = perf_time__range_alloc(time_str, &size);
+ if (!ptime_range)
+ return -ENOMEM;
+
+ if (perf_time__parse_str(ptime_range, time_str) != 0) {
+ if (session->evlist->first_sample_time == 0 &&
+ session->evlist->last_sample_time == 0) {
+ pr_err("HINT: no first/last sample time found in perf data.\n"
+ "Please use latest perf binary to execute 'perf record'\n"
+ "(if '--buildid-all' is enabled, please set '--timestamp-boundary').\n");
+ ret = -EINVAL;
+ goto error;
+ }
+
+ num = perf_time__percent_parse_str(
+ ptime_range, size,
+ time_str,
+ session->evlist->first_sample_time,
+ session->evlist->last_sample_time);
+
+ if (num < 0) {
+ pr_err("Invalid time string\n");
+ ret = -EINVAL;
+ goto error;
+ }
+ } else {
+ num = 1;
+ }
+
+ *range_size = size;
+ *range_num = num;
+ *ranges = ptime_range;
+ return 0;
+
+error:
+ free(ptime_range);
+ return ret;
+}
+
int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz)
{
u64 sec = timestamp / NSEC_PER_SEC;
diff --git a/tools/perf/util/time-utils.h b/tools/perf/util/time-utils.h
index 70b177d2b98c..b923de44e36f 100644
--- a/tools/perf/util/time-utils.h
+++ b/tools/perf/util/time-utils.h
@@ -23,6 +23,12 @@ bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp);
bool perf_time__ranges_skip_sample(struct perf_time_interval *ptime_buf,
int num, u64 timestamp);

+struct perf_session;
+
+int perf_time__parse_for_ranges(const char *str, struct perf_session *session,
+ struct perf_time_interval **ranges,
+ int *range_size, int *range_num);
+
int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz);

int fetch_current_timestamp(char *buf, size_t sz);
--
2.20.1