// SPDX-License-Identifier: GPL-2.0
/* scx_perfprobe userspace - prints one line per second with every
 * CPU's rq->scx.cpuperf_target. */
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <bpf/bpf.h>
#include <scx/common.h>
#include "scx_perfprobe.bpf.skel.h"

#define K2_MAX_CPUS 128

static volatile int exit_req;

static void sig_handler(int sig)
{
	exit_req = 1;
}

int main(int argc, char **argv)
{
	struct scx_perfprobe *skel;
	struct bpf_link *link;
	long online = sysconf(_SC_NPROCESSORS_ONLN);
	unsigned long sec = 0;

	signal(SIGINT, sig_handler);
	signal(SIGTERM, sig_handler);

	skel = scx_perfprobe__open();
	if (!skel) {
		fprintf(stderr, "perfprobe: open failed\n");
		return 1;
	}
	if (scx_perfprobe__load(skel)) {
		fprintf(stderr, "perfprobe: load failed\n");
		return 1;
	}
	link = bpf_program__attach(skel->progs.k2_sample_tick);
	if (libbpf_get_error(link)) {
		fprintf(stderr, "perfprobe: attach failed\n");
		return 1;
	}

	while (!exit_req) {
		char line[1024];
		int n = 0, cpu;

		n += snprintf(line + n, sizeof(line) - n, "[T+%lus]", ++sec);
		for (cpu = 0; cpu < online && cpu < K2_MAX_CPUS; cpu++) {
			u64 v = 0;
			u32 key = cpu;

			bpf_map_lookup_elem(bpf_map__fd(skel->maps.targets),
					    &key, &v);
			u64 tk = 0;
			bpf_map_lookup_elem(bpf_map__fd(skel->maps.tickcnt),
					    &key, &tk);
			n += snprintf(line + n, sizeof(line) - n,
				      " c%d=%llu/t%llu", cpu,
				      (unsigned long long)v,
				      (unsigned long long)tk);
		}
		printf("%s\n", line);
		fflush(stdout);
		sleep(1);
	}

	bpf_link__destroy(link);
	scx_perfprobe__destroy(skel);
	return 0;
}