tools/testing/selftests/bpf/progs/perfbuf_bench.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/perfbuf_bench.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/perfbuf_bench.c
Extension
.c
Size
728 bytes
Lines
34
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook

#include <linux/bpf.h>
#include <stdint.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"

char _license[] SEC("license") = "GPL";

struct {
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	__uint(value_size, sizeof(int));
	__uint(key_size, sizeof(int));
} perfbuf SEC(".maps");

const volatile int batch_cnt = 0;

long sample_val = 42;
long dropped __attribute__((aligned(128))) = 0;

SEC("fentry/" SYS_PREFIX "sys_getpgid")
int bench_perfbuf(void *ctx)
{
	int i;

	for (i = 0; i < batch_cnt; i++) {
		if (bpf_perf_event_output(ctx, &perfbuf, BPF_F_CURRENT_CPU,
					  &sample_val, sizeof(sample_val)))
			__sync_add_and_fetch(&dropped, 1);
	}
	return 0;
}

Annotation

Implementation Notes