Commit 9e3d47df authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

sysctl: Make the header lists per directory. 



Slightly enhance efficiency and clarity of the code by making the
header list per directory instead of per set.

Benchmark before:
    make-dummies 0 999 -> 0.63s
    rmmod dummy        -> 0.12s
    make-dummies 0 9999 -> 2m35s
    rmmod dummy         -> 18s

Benchmark after:
    make-dummies 0 999 -> 0.32s
    rmmod dummy        -> 0.12s
    make-dummies 0 9999 -> 1m17s
    rmmod dummy         -> 17s

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent e54012ce

fs/proc/proc_sysctl.c

+11 −17
Original line number Diff line number Diff line
@@ -33,12 +33,12 @@ static struct ctl_table root_table[] = { 
	{ }

};

static struct ctl_table_root sysctl_table_root = {

	.default_set.list = LIST_HEAD_INIT(sysctl_table_root.default_set.dir.header.ctl_entry),

	.default_set.dir.list = LIST_HEAD_INIT(sysctl_table_root.default_set.dir.list),

	.default_set.dir.header = {

		{{.count = 1,

		  .nreg = 1,

		  .ctl_table = root_table,

		  .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},

		  .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.dir.header.ctl_entry),}},

		.ctl_table_arg = root_table,

		.root = &sysctl_table_root,

		.set = &sysctl_table_root.default_set,
@@ -79,15 +79,12 @@ static int namecmp(const char *name1, int len1, const char *name2, int len2) 
static struct ctl_table *find_entry(struct ctl_table_header **phead,

	struct ctl_dir *dir, const char *name, int namelen)

{

	struct ctl_table_set *set = dir->header.set;

	struct ctl_table_header *head;

	struct ctl_table *entry;



	list_for_each_entry(head, &set->list, ctl_entry) {

	list_for_each_entry(head, &dir->list, ctl_entry) {

		if (head->unregistering)

			continue;

		if (head->parent != dir)

			continue;

		for (entry = head->ctl_table; entry->procname; entry++) {

			const char *procname = entry->procname;

			if (namecmp(procname, strlen(procname), name, namelen) == 0) {
@@ -133,7 +130,7 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) 
	err = insert_links(header);

	if (err)

		goto fail_links;

	list_add_tail(&header->ctl_entry, &header->set->list);

	list_add_tail(&header->ctl_entry, &header->parent->list);

	return 0;

fail_links:

	header->parent = NULL;
@@ -247,14 +244,12 @@ static struct ctl_table *lookup_entry(struct ctl_table_header **phead, 
static struct ctl_table_header *next_usable_entry(struct ctl_dir *dir,

						  struct list_head *tmp)

{

	struct ctl_table_set *set = dir->header.set;

	struct ctl_table_header *head;



	for (tmp = tmp->next; tmp != &set->list; tmp = tmp->next) {

	for (tmp = tmp->next; tmp != &dir->list; tmp = tmp->next) {

		head = list_entry(tmp, struct ctl_table_header, ctl_entry);



		if (head->parent != dir ||

		    !head->ctl_table->procname ||

		if (!head->ctl_table->procname ||

		    !use_table(head))

			continue;
@@ -270,7 +265,7 @@ static void first_entry(struct ctl_dir *dir, 
	struct ctl_table *entry = NULL;



	spin_lock(&sysctl_lock);

	head = next_usable_entry(dir, &dir->header.set->list);

	head = next_usable_entry(dir, &dir->list);

	spin_unlock(&sysctl_lock);

	if (head)

		entry = head->ctl_table;
@@ -793,6 +788,7 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set, 
	new_name = (char *)(table + 2);

	memcpy(new_name, name, namelen);

	new_name[namelen] = '\0';

	INIT_LIST_HEAD(&new->list);

	table[0].procname = new_name;

	table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO;

	init_header(&new->header, set->dir.header.root, set, table);
@@ -917,12 +913,10 @@ static int sysctl_check_table_dups(struct ctl_dir *dir, struct ctl_table *old, 


static int sysctl_check_dups(struct ctl_dir *dir, struct ctl_table *table)

{

	struct ctl_table_set *set;

	struct ctl_table_header *head;

	int error = 0;



	set = dir->header.set;

	list_for_each_entry(head, &set->list, ctl_entry) {

	list_for_each_entry(head, &dir->list, ctl_entry) {

		if (head->unregistering)

			continue;

		if (head->parent != dir)
@@ -1494,14 +1488,14 @@ void setup_sysctl_set(struct ctl_table_set *set, 
	int (*is_seen)(struct ctl_table_set *))

{

	memset(set, sizeof(*set), 0);

	INIT_LIST_HEAD(&set->list);

	set->is_seen = is_seen;

	INIT_LIST_HEAD(&set->dir.list);

	init_header(&set->dir.header, root, set, root_table);

}



void retire_sysctl_set(struct ctl_table_set *set)

{

	WARN_ON(!list_empty(&set->list));

	WARN_ON(!list_empty(&set->dir.list));

}



int __init proc_sys_init(void)

include/linux/sysctl.h

+1 −1
Original line number Diff line number Diff line
@@ -1047,10 +1047,10 @@ struct ctl_table_header 
struct ctl_dir {

	/* Header must be at the start of ctl_dir */

	struct ctl_table_header header;

	struct list_head list;

};



struct ctl_table_set {

	struct list_head list;

	int (*is_seen)(struct ctl_table_set *);

	struct ctl_dir dir;

};

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