1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
* Copyright (c) 2023 Tejun Heo <tj@kernel.org>
* Copyright (c) 2023 David Vernet <dvernet@meta.com>
*/
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <libgen.h>
#include <limits.h>
#include <inttypes.h>
#include <fcntl.h>
#include <time.h>
#include <bpf/bpf.h>
#include <scx/common.h>
#include "scx_flatcg.h"
#include "scx_flatcg.bpf.skel.h"
#ifndef FILEID_KERNFS
#define FILEID_KERNFS 0xfe
#endif
const char help_fmt[] =
"A flattened cgroup hierarchy sched_ext scheduler.\n"
"\n"
"See the top-level comment in .bpf.c for more details.\n"
"\n"
"Usage: %s [-s SLICE_US] [-i INTERVAL] [-f] [-v]\n"
"\n"
" -s SLICE_US Override slice duration\n"
" -i INTERVAL Report interval\n"
" -f Use FIFO scheduling instead of weighted vtime scheduling\n"
" -v Print libbpf debug messages\n"
" -h Display this help and exit\n";
static bool verbose;
static volatile int exit_req;
static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
{
if (level == LIBBPF_DEBUG && !verbose)
return 0;
return vfprintf(stderr, format, args);
}
static void sigint_handler(int dummy)
{
exit_req = 1;
}
static float read_cpu_util(__u64 *last_sum, __u64 *last_idle)
{
FILE *fp;
char buf[4096];
char *line, *cur = NULL, *tok;
__u64 sum = 0, idle = 0;
__u64 delta_sum, delta_idle;
int idx;
fp = fopen("/proc/stat", "r");
if (!fp) {
perror("fopen(\"/proc/stat\")");
return 0.0;
}
if (!fgets(buf, sizeof(buf), fp)) {
perror("fgets(\"/proc/stat\")");
fclose(fp);
return 0.0;
}
fclose(fp);
line = buf;
for (idx = 0; (tok = strtok_r(line, " \n", &cur)); idx++) {
char *endp = NULL;
__u64 v;
if (idx == 0) {
line = NULL;
continue;
}
v = strtoull(tok, &endp, 0);
if (!endp || *endp != '\0') {
fprintf(stderr, "failed to parse %dth field of /proc/stat (\"%s\")\n",
idx, tok);
continue;
}
sum += v;
if (idx == 4)
idle = v;
}
delta_sum = sum - *last_sum;
delta_idle = idle - *last_idle;
*last_sum = sum;
*last_idle = idle;
return delta_sum ? (float)(delta_sum - delta_idle) / delta_sum : 0.0;
}
static void fcg_read_stats(struct scx_flatcg *skel, __u64 *stats)
{
__u64 cnts[FCG_NR_STATS][skel->rodata->nr_cpus];
__u32 idx;
memset(stats, 0, sizeof(stats[0]) * FCG_NR_STATS);
for (idx = 0; idx < FCG_NR_STATS; idx++) {
int ret, cpu;
ret = bpf_map_lookup_elem(bpf_map__fd(skel->maps.stats),
&idx, cnts[idx]);
if (ret < 0)
continue;
for (cpu = 0; cpu < skel->rodata->nr_cpus; cpu++)
stats[idx] += cnts[idx][cpu];
}
}
int main(int argc, char **argv)
{
struct scx_flatcg *skel;
struct bpf_link *link;
struct timespec intv_ts = { .tv_sec = 2, .tv_nsec = 0 };
bool dump_cgrps = false;
__u64 last_cpu_sum = 0, last_cpu_idle = 0;
__u64 last_stats[FCG_NR_STATS] = {};
unsigned long seq = 0;
__s32 opt;
__u64 ecode;
libbpf_set_print(libbpf_print_fn);
signal(SIGINT, sigint_handler);
signal(SIGTERM, sigint_handler);
restart:
skel = SCX_OPS_OPEN(flatcg_ops, scx_flatcg);
skel->rodata->nr_cpus = libbpf_num_possible_cpus();
while ((opt = getopt(argc, argv, "s:i:dfvh")) != -1) {
double v;
switch (opt) {
case 's':
v = strtod(optarg, NULL);
skel->rodata->cgrp_slice_ns = v * 1000;
break;
case 'i':
v = strtod(optarg, NULL);
intv_ts.tv_sec = v;
intv_ts.tv_nsec = (v - (float)intv_ts.tv_sec) * 1000000000;
break;
case 'd':
dump_cgrps = true;
break;
case 'f':
skel->rodata->fifo_sched = true;
break;
case 'v':
verbose = true;
break;
case 'h':
default:
fprintf(stderr, help_fmt, basename(argv[0]));
return opt != 'h';
}
}
printf("slice=%.1lfms intv=%.1lfs dump_cgrps=%d",
(double)skel->rodata->cgrp_slice_ns / 1000000.0,
(double)intv_ts.tv_sec + (double)intv_ts.tv_nsec / 1000000000.0,
dump_cgrps);
SCX_OPS_LOAD(skel, flatcg_ops, scx_flatcg, uei);
link = SCX_OPS_ATTACH(skel, flatcg_ops, scx_flatcg);
while (!exit_req && !UEI_EXITED(skel, uei)) {
__u64 acc_stats[FCG_NR_STATS];
__u64 stats[FCG_NR_STATS];
float cpu_util;
int i;
cpu_util = read_cpu_util(&last_cpu_sum, &last_cpu_idle);
fcg_read_stats(skel, acc_stats);
for (i = 0; i < FCG_NR_STATS; i++)
stats[i] = acc_stats[i] - last_stats[i];
memcpy(last_stats, acc_stats, sizeof(acc_stats));
printf("\n[SEQ %6lu cpu=%5.1lf hweight_gen=%" PRIu64 "]\n",
seq++, cpu_util * 100.0, skel->data->hweight_gen);
printf(" act:%6llu deact:%6llu global:%6llu local:%6llu\n",
stats[FCG_STAT_ACT],
stats[FCG_STAT_DEACT],
stats[FCG_STAT_GLOBAL],
stats[FCG_STAT_LOCAL]);
printf("HWT cache:%6llu update:%6llu skip:%6llu race:%6llu\n",
stats[FCG_STAT_HWT_CACHE],
stats[FCG_STAT_HWT_UPDATES],
stats[FCG_STAT_HWT_SKIP],
stats[FCG_STAT_HWT_RACE]);
printf("ENQ skip:%6llu race:%6llu\n",
stats[FCG_STAT_ENQ_SKIP],
stats[FCG_STAT_ENQ_RACE]);
printf("CNS keep:%6llu expire:%6llu empty:%6llu gone:%6llu\n",
stats[FCG_STAT_CNS_KEEP],
stats[FCG_STAT_CNS_EXPIRE],
stats[FCG_STAT_CNS_EMPTY],
stats[FCG_STAT_CNS_GONE]);
printf("PNC next:%6llu empty:%6llu nocgrp:%6llu gone:%6llu race:%6llu fail:%6llu\n",
stats[FCG_STAT_PNC_NEXT],
stats[FCG_STAT_PNC_EMPTY],
stats[FCG_STAT_PNC_NO_CGRP],
stats[FCG_STAT_PNC_GONE],
stats[FCG_STAT_PNC_RACE],
stats[FCG_STAT_PNC_FAIL]);
printf("BAD remove:%6llu\n",
acc_stats[FCG_STAT_BAD_REMOVAL]);
fflush(stdout);
nanosleep(&intv_ts, NULL);
}
bpf_link__destroy(link);
ecode = UEI_REPORT(skel, uei);
scx_flatcg__destroy(skel);
if (UEI_ECODE_RESTART(ecode))
goto restart;
return 0;
}
|
