libbpf-tools: add CO-RE 'pidpersec'

libbpf-tools/.gitignore

@@ -43,6 +43,7 @@
 /offcputime
 /oomkill
 /opensnoop
+/pidpersec
 /profile
 /readahead
 /runqlat

libbpf-tools/Makefile

@@ -70,6 +70,7 @@ APPS = \
 	numamove \
 	offcputime \
 	oomkill \
+	pidpersec \
 	profile \
 	readahead \
 	runqlat \

libbpf-tools/pidpersec.bpf.c

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2024 Tiago Ilieve
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include "pidpersec.h"
+
+__u64 stats[S_MAXSTAT] = {};
+
+SEC("tracepoint/sched/sched_process_fork")
+int tracepoint__sched__sched_process_fork(void *ctx)
+{
+	__atomic_add_fetch(&stats[S_COUNT], 1, __ATOMIC_RELAXED);
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";

libbpf-tools/pidpersec.c

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+// Copyright (c) 2024 Tiago Ilieve
+//
+// Based on pidpersec(8) from BCC by Brendan Gregg.
+// 12-Apr-2024   Tiago Ilieve   Created this.
+#include <argp.h>
+#include <signal.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+#include <bpf/libbpf.h>
+#include "pidpersec.h"
+#include "pidpersec.skel.h"
+
+static volatile sig_atomic_t exiting = 0;
+
+struct env {
+	bool verbose;
+} env = {};
+
+const char *argp_program_version = "pidpersec 0.1";
+const char *argp_program_bug_address =
+	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
+const char argp_program_doc[] =
+"Count new processes (via fork).\n"
+"\n"
+"USAGE: pidpersec [--help]\n"
+"\n"
+"EXAMPLES:\n"
+"    pidpersec  # count new processes\n";
+
+static const struct argp_option opts[] = {
+	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
+	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
+	{},
+};
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+	switch (key) {
+	case 'v':
+		env.verbose = true;
+		break;
+	case 'h':
+		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
+		break;
+	default:
+		return ARGP_ERR_UNKNOWN;
+	}
+	return 0;
+}
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+	if (level == LIBBPF_DEBUG && !env.verbose)
+		return 0;
+	return vfprintf(stderr, format, args);
+}
+
+static void sig_int(int signo)
+{
+	exiting = 1;
+}
+
+int main(int argc, char **argv)
+{
+	static const struct argp argp = {
+		.options = opts,
+		.parser = parse_arg,
+		.doc = argp_program_doc,
+	};
+	struct pidpersec_bpf *obj;
+	int err;
+
+	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
+	if (err)
+		return err;
+
+	libbpf_set_print(libbpf_print_fn);
+
+	obj = pidpersec_bpf__open_and_load();
+	if (!obj) {
+		fprintf(stderr, "failed to open and load BPF object\n");
+		return 1;
+	}
+
+	err = pidpersec_bpf__attach(obj);
+	if (err) {
+		fprintf(stderr, "failed to attach BPF object\n");
+		return 1;
+	}
+
+	if (signal(SIGINT, sig_int) == SIG_ERR) {
+		fprintf(stderr, "can't set signal handler: %s\n", strerror(errno));
+		err = 1;
+		goto cleanup;
+	}
+
+	/* print header */
+	printf("Tracing... Ctrl-C to end.\n");
+
+	while (!exiting) {
+		struct tm *tm;
+		char ts[16];
+		__u64 val;
+		time_t t;
+
+		sleep(1);
+
+		time(&t);
+		tm = localtime(&t);
+		strftime(ts, sizeof(ts), "%H:%M:%S", tm);
+		val = __atomic_exchange_n(&obj->bss->stats[S_COUNT], 0, __ATOMIC_RELAXED);
+		printf("%s: PIDs/sec: %llu\n", ts, val);
+	}
+
+cleanup:
+	pidpersec_bpf__destroy(obj);
+
+	return err != 0;
+}

libbpf-tools/pidpersec.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __PIDPERSEC_H
+#define __PIDPERSEC_H
+
+enum stat_types {
+	S_COUNT = 1,
+	S_MAXSTAT
+};
+
+#endif /* __PIDPERSEC_H */

man/man8/pidpersec.8

@@ -36,6 +36,7 @@ Linux
 .SH STABILITY
 Unstable - in development.
 .SH AUTHOR
-Brendan Gregg
+Brendan Gregg, original BCC Python version
+Tiago Ilieve, CO-RE version
 .SH SEE ALSO
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