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

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
Extension
.c
Size
1279 bytes
Lines
46
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) 2025 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_core_read.h>
#include "cgroup_iter_memcg.h"

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

/* The latest values read are stored here. */
struct memcg_query memcg_query SEC(".data.query");

SEC("iter.s/cgroup")
int cgroup_memcg_query(struct bpf_iter__cgroup *ctx)
{
	struct cgroup *cgrp = ctx->cgroup;
	struct cgroup_subsys_state *css;
	struct mem_cgroup *memcg;

	if (!cgrp)
		return 1;

	css = &cgrp->self;
	memcg = bpf_get_mem_cgroup(css);
	if (!memcg)
		return 1;

	bpf_mem_cgroup_flush_stats(memcg);

	memcg_query.nr_anon_mapped = bpf_mem_cgroup_page_state(
		memcg,
		bpf_core_enum_value(enum node_stat_item, NR_ANON_MAPPED));
	memcg_query.nr_shmem = bpf_mem_cgroup_page_state(
		memcg, bpf_core_enum_value(enum node_stat_item, NR_SHMEM));
	memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(
		memcg, bpf_core_enum_value(enum node_stat_item, NR_FILE_PAGES));
	memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(
		memcg,
		bpf_core_enum_value(enum node_stat_item, NR_FILE_MAPPED));
	memcg_query.pgfault = bpf_mem_cgroup_vm_events(
		memcg, bpf_core_enum_value(enum vm_event_item, PGFAULT));

	bpf_put_mem_cgroup(memcg);

	return 0;
}

Annotation

Implementation Notes