libbpf-tools: add profile

libbpf-tools/.gitignore

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

libbpf-tools/Makefile

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

libbpf-tools/profile.bpf.c

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/*
+ * Copyright (c) 2022 LG Electronics
+ *
+ * Based on profile from BCC by Brendan Gregg and others.
+ * 28-Dec-2021   Eunseon Lee   Created this.
+ */
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_tracing.h>
+#include "profile.h"
+#include "maps.bpf.h"
+
+const volatile bool kernel_stacks_only = false;
+const volatile bool user_stacks_only = false;
+const volatile bool include_idle = false;
+const volatile pid_t targ_pid = -1;
+const volatile pid_t targ_tid = -1;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__type(key, u32);
+} stackmap SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct key_t);
+	__type(value, u64);
+	__uint(max_entries, MAX_ENTRIES);
+} counts SEC(".maps");
+
+SEC("perf_event")
+int do_perf_event(struct bpf_perf_event_data *ctx)
+{
+	u64 id = bpf_get_current_pid_tgid();
+	u32 pid = id >> 32;
+	u32 tid = id;
+	u64 *valp;
+	static const u64 zero;
+	struct key_t key = {};
+
+	if (!include_idle && tid == 0)
+		return 0;
+
+	if (targ_pid != -1 && targ_pid != pid)
+		return 0;
+
+	if (targ_tid != -1 && targ_tid != tid)
+		return 0;
+
+	key.pid = pid;
+	bpf_get_current_comm(&key.name, sizeof(key.name));
+
+	if (user_stacks_only)
+		key.kern_stack_id = -1;
+	else
+		key.kern_stack_id = bpf_get_stackid(&ctx->regs, &stackmap, 0);
+
+	if (kernel_stacks_only)
+		key.user_stack_id = -1;
+	else
+		key.user_stack_id = bpf_get_stackid(&ctx->regs, &stackmap,
+						    BPF_F_USER_STACK);
+
+	valp = bpf_map_lookup_or_try_init(&counts, &key, &zero);
+	if (valp)
+		__sync_fetch_and_add(valp, 1);
+
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";