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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
* Copyright (c) 2022 Tejun Heo <tj@kernel.org>
* Copyright (c) 2022 David Vernet <dvernet@meta.com>
*/
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <libgen.h>
#include <bpf/bpf.h>
#include <scx/common.h>
#include "scx_simple.bpf.skel.h"
const char help_fmt[] =
"A simple sched_ext scheduler.\n"
"\n"
"See the top-level comment in .bpf.c for more details.\n"
"\n"
"Usage: %s [-f] [-v]\n"
"\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 simple)
{
exit_req = 1;
}
static void read_stats(struct scx_simple *skel, __u64 *stats)
{
int nr_cpus = libbpf_num_possible_cpus();
__u64 cnts[2][nr_cpus];
__u32 idx;
memset(stats, 0, sizeof(stats[0]) * 2);
for (idx = 0; idx < 2; 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 < nr_cpus; cpu++)
stats[idx] += cnts[idx][cpu];
}
}
int main(int argc, char **argv)
{
struct scx_simple *skel;
struct bpf_link *link;
__u32 opt;
__u64 ecode;
libbpf_set_print(libbpf_print_fn);
signal(SIGINT, sigint_handler);
signal(SIGTERM, sigint_handler);
restart:
skel = SCX_OPS_OPEN(simple_ops, scx_simple);
while ((opt = getopt(argc, argv, "fvh")) != -1) {
switch (opt) {
case 'f':
skel->rodata->fifo_sched = true;
break;
case 'v':
verbose = true;
break;
default:
fprintf(stderr, help_fmt, basename(argv[0]));
return opt != 'h';
}
}
SCX_OPS_LOAD(skel, simple_ops, scx_simple, uei);
link = SCX_OPS_ATTACH(skel, simple_ops, scx_simple);
while (!exit_req && !UEI_EXITED(skel, uei)) {
__u64 stats[2];
read_stats(skel, stats);
printf("local=%llu global=%llu\n", stats[0], stats[1]);
fflush(stdout);
sleep(1);
}
bpf_link__destroy(link);
ecode = UEI_REPORT(skel, uei);
scx_simple__destroy(skel);
if (UEI_ECODE_RESTART(ecode))
goto restart;
return 0;
}
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