mm/hugetlb_sysfs.c

Source file repositories/reference/linux-study-clean/mm/hugetlb_sysfs.c

File Facts

System
Linux kernel
Corpus path
mm/hugetlb_sysfs.c
Extension
.c
Size
11979 bytes
Lines
503
Domain
Core OS
Bucket
Memory Management
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct node_hstate {
	struct kobject		*hugepages_kobj;
	struct kobject		*hstate_kobjs[HUGE_MAX_HSTATE];
};
static struct node_hstate node_hstates[MAX_NUMNODES];

/*
 * A subset of global hstate attributes for node devices
 */
static struct attribute *per_node_hstate_attrs[] = {
	&nr_hugepages_attr.attr,
	&free_hugepages_attr.attr,
	&surplus_hugepages_attr.attr,
	NULL,
};

static const struct attribute_group per_node_hstate_attr_group = {
	.attrs = per_node_hstate_attrs,
};

/*
 * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
 * Returns node id via non-NULL nidp.
 */
static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
{
	int nid;

	for (nid = 0; nid < nr_node_ids; nid++) {
		struct node_hstate *nhs = &node_hstates[nid];
		int i;
		for (i = 0; i < HUGE_MAX_HSTATE; i++)
			if (nhs->hstate_kobjs[i] == kobj) {
				if (nidp)
					*nidp = nid;
				return &hstates[i];
			}
	}

	BUG();
	return NULL;
}

/*
 * Unregister hstate attributes from a single node device.
 * No-op if no hstate attributes attached.
 */
void hugetlb_unregister_node(struct node *node)
{
	struct hstate *h;
	struct node_hstate *nhs = &node_hstates[node->dev.id];

	if (!nhs->hugepages_kobj)
		return;		/* no hstate attributes */

	for_each_hstate(h) {
		int idx = hstate_index(h);
		struct kobject *hstate_kobj = nhs->hstate_kobjs[idx];

		if (!hstate_kobj)
			continue;
		if (h->demote_order)
			sysfs_remove_group(hstate_kobj, &hstate_demote_attr_group);
		sysfs_remove_group(hstate_kobj, &per_node_hstate_attr_group);
		kobject_put(hstate_kobj);
		nhs->hstate_kobjs[idx] = NULL;
	}

	kobject_put(nhs->hugepages_kobj);
	nhs->hugepages_kobj = NULL;
}


/*
 * Register hstate attributes for a single node device.
 * No-op if attributes already registered.
 */
void hugetlb_register_node(struct node *node)
{
	struct hstate *h;
	struct node_hstate *nhs = &node_hstates[node->dev.id];
	int err;

	if (!hugetlb_sysfs_initialized)
		return;

	if (nhs->hugepages_kobj)
		return;		/* already allocated */

	nhs->hugepages_kobj = kobject_create_and_add("hugepages",

Annotation

Implementation Notes