samples/bpf/lwt_len_hist_user.c

File Facts

System

Linux kernel

Corpus path

samples/bpf/lwt_len_hist_user.c

Extension

.c

Size

1653 bytes

Lines

78

Domain

Support Tooling And Documentation

Bucket

samples

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.

Dependency Surface

• linux/unistd.h
• linux/bpf.h
• stdlib.h
• stdio.h
• unistd.h
• string.h
• errno.h
• arpa/inet.h
• bpf/bpf.h
• bpf_util.h

Detected Declarations

• function stars
• function main

Annotated Snippet

if (next_key >= MAX_INDEX) {
			fprintf(stderr, "Key %lu out of bounds\n", next_key);
			continue;
		}

		bpf_map_lookup_elem(map_fd, &next_key, values);

		sum = 0;
		for (i = 0; i < nr_cpus; i++)
			sum += values[i];

		data[next_key] = sum;
		if (sum && next_key > max_key)
			max_key = next_key;

		if (sum > max_value)
			max_value = sum;

		key = next_key;
	}

	for (i = 1; i <= max_key + 1; i++) {
		stars(starstr, data[i - 1], max_value, MAX_STARS);
		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
		       MAX_STARS, starstr);
	}

	close(map_fd);

	return 0;
}

Annotation

• Immediate include surface: `linux/unistd.h`, `linux/bpf.h`, `stdlib.h`, `stdio.h`, `unistd.h`, `string.h`, `errno.h`, `arpa/inet.h`.
• Detected declarations: `function stars`, `function main`.
• Atlas domain: Support Tooling And Documentation / samples.
• 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.