forked from Minki/linux
6859bc0e78
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>
77 lines
1.2 KiB
C
77 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include "units.h"
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#include <inttypes.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <string.h>
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#include <linux/kernel.h>
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#include <linux/time64.h>
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unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
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{
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struct parse_tag *i = tags;
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while (i->tag) {
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char *s = strchr(str, i->tag);
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if (s) {
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unsigned long int value;
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char *endptr;
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value = strtoul(str, &endptr, 10);
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if (s != endptr)
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break;
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if (value > ULONG_MAX / i->mult)
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break;
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value *= i->mult;
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return value;
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}
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i++;
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}
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return (unsigned long) -1;
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}
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double convert_unit_double(double value, char *unit)
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{
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*unit = ' ';
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if (value > 1000.0) {
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value /= 1000.0;
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*unit = 'K';
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}
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if (value > 1000.0) {
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value /= 1000.0;
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*unit = 'M';
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}
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if (value > 1000.0) {
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value /= 1000.0;
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*unit = 'G';
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}
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return value;
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}
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unsigned long convert_unit(unsigned long value, char *unit)
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{
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double v = convert_unit_double((double)value, unit);
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return (unsigned long)v;
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}
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int unit_number__scnprintf(char *buf, size_t size, u64 n)
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{
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char unit[4] = "BKMG";
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int i = 0;
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while (((n / 1024) > 1) && (i < 3)) {
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n /= 1024;
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i++;
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}
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return scnprintf(buf, size, "%" PRIu64 "%c", n, unit[i]);
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}
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