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author | Changbin Du <changbin.du@gmail.com> | 2021-03-15 17:30:47 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-03-15 17:36:54 +0300 |
commit | 6859bc0e78c6a699599cbb21404fdb6c8125da74 (patch) | |
tree | cf5b4d2136ed5289fe45800f6b750542298fd728 /tools/perf/util/units.c | |
parent | 4a03af3ee399e87934e18ae720dda72c52f0050c (diff) | |
download | linux-6859bc0e78c6a699599cbb21404fdb6c8125da74.tar.xz |
perf stat: Improve readability of shadow stats
This adds function convert_unit_double() and selects appropriate
unit for shadow stats between K/M/G.
$ sudo perf stat -a -- sleep 1
Before: Unit 'M' is selected even the number is very small.
Performance counter stats for 'system wide':
4,003.06 msec cpu-clock # 3.998 CPUs utilized
16,179 context-switches # 0.004 M/sec
161 cpu-migrations # 0.040 K/sec
4,699 page-faults # 0.001 M/sec
6,135,801,925 cycles # 1.533 GHz (83.21%)
5,783,308,491 stalled-cycles-frontend # 94.26% frontend cycles idle (83.21%)
4,543,694,050 stalled-cycles-backend # 74.05% backend cycles idle (66.49%)
4,720,130,587 instructions # 0.77 insn per cycle
# 1.23 stalled cycles per insn (83.28%)
753,848,078 branches # 188.318 M/sec (83.61%)
37,457,747 branch-misses # 4.97% of all branches (83.48%)
1.001283725 seconds time elapsed
After:
$ sudo perf stat -a -- sleep 2
Performance counter stats for 'system wide':
8,005.52 msec cpu-clock # 3.999 CPUs utilized
10,715 context-switches # 1.338 K/sec
785 cpu-migrations # 98.057 /sec
102 page-faults # 12.741 /sec
1,948,202,279 cycles # 0.243 GHz
2,816,470,932 stalled-cycles-frontend # 144.57% frontend cycles idle
2,661,172,207 stalled-cycles-backend # 136.60% backend cycles idle
464,172,105 instructions # 0.24 insn per cycle
# 6.07 stalled cycles per insn
91,567,662 branches # 11.438 M/sec
7,756,054 branch-misses # 8.47% of all branches
2.002040043 seconds time elapsed
v2:
o do not change 'sec' to 'cpu-sec'.
o use convert_unit_double to implement convert_unit.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210315143047.3867-1-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/units.c')
-rw-r--r-- | tools/perf/util/units.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/tools/perf/util/units.c b/tools/perf/util/units.c index a46762aec4c9..32c39cfe209b 100644 --- a/tools/perf/util/units.c +++ b/tools/perf/util/units.c @@ -33,28 +33,35 @@ unsigned long parse_tag_value(const char *str, struct parse_tag *tags) return (unsigned long) -1; } -unsigned long convert_unit(unsigned long value, char *unit) +double convert_unit_double(double value, char *unit) { *unit = ' '; - if (value > 1000) { - value /= 1000; + if (value > 1000.0) { + value /= 1000.0; *unit = 'K'; } - if (value > 1000) { - value /= 1000; + if (value > 1000.0) { + value /= 1000.0; *unit = 'M'; } - if (value > 1000) { - value /= 1000; + if (value > 1000.0) { + value /= 1000.0; *unit = 'G'; } return value; } +unsigned long convert_unit(unsigned long value, char *unit) +{ + double v = convert_unit_double((double)value, unit); + + return (unsigned long)v; +} + int unit_number__scnprintf(char *buf, size_t size, u64 n) { char unit[4] = "BKMG"; |