/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
* Copyright (c) 2023 Tejun Heo <[email protected]>
* Copyright (c) 2023 David Vernet <[email protected]>
*/
#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;
}
Codebase Browser
linux