tools/testing/selftests/bpf/prog_tests/perf_buffer.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/bpf/prog_tests/perf_buffer.c- Extension
.c- Size
- 3718 bytes
- Lines
- 148
- 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.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
pthread.hsched.hsys/socket.htest_progs.htest_perf_buffer.skel.hbpf/libbpf_internal.h
Detected Declarations
function mmapfunction trigger_on_cpufunction serial_test_perf_buffer
Annotated Snippet
if (i >= on_len || !online[i]) {
printf("skipping offline CPU #%d\n", i);
continue;
}
if (trigger_on_cpu(i))
goto out_close;
}
/* read perf buffer */
err = perf_buffer__poll(pb, 100);
if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
goto out_free_pb;
if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
"expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
goto out_free_pb;
if (CHECK(perf_buffer__buffer_cnt(pb) != nr_on_cpus, "buf_cnt",
"got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_on_cpus))
goto out_close;
for (i = 0, j = 0; i < nr_cpus; i++) {
if (i >= on_len || !online[i])
continue;
fd = perf_buffer__buffer_fd(pb, j);
CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd);
last_fd = fd;
err = perf_buffer__consume_buffer(pb, j);
if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err))
goto out_close;
CPU_CLR(i, &cpu_seen);
if (trigger_on_cpu(i))
goto out_close;
err = perf_buffer__consume_buffer(pb, j);
if (CHECK(err, "consume_buf", "cpu %d, err %d\n", j, err))
goto out_close;
if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i))
goto out_close;
j++;
}
out_free_pb:
perf_buffer__free(pb);
out_close:
test_perf_buffer__destroy(skel);
free(online);
}
Annotation
- Immediate include surface: `pthread.h`, `sched.h`, `sys/socket.h`, `test_progs.h`, `test_perf_buffer.skel.h`, `bpf/libbpf_internal.h`.
- Detected declarations: `function mmap`, `function trigger_on_cpu`, `function serial_test_perf_buffer`.
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.