cgroup: use new hashtable implementation (0ac801fe) · Commits · e / devices / android_kernel_fairphone_FP4

kernel/cgroup.c

+39 −53

Original line number	Diff line number	Diff line
		@@ -52,7 +52,7 @@
		#include <linux/module.h>
		#include <linux/delayacct.h>
		#include <linux/cgroupstats.h>
		#include <linux/hash.h>
		#include <linux/hashtable.h>
		#include <linux/namei.h>
		#include <linux/pid_namespace.h>
		#include <linux/idr.h>
		@@ -376,22 +376,18 @@ static int css_set_count;
		* account cgroups in empty hierarchies.
		*/
		#define CSS_SET_HASH_BITS 7
		#define CSS_SET_TABLE_SIZE (1 << CSS_SET_HASH_BITS)
		static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE];
		static DEFINE_HASHTABLE(css_set_table, CSS_SET_HASH_BITS);

		static struct hlist_head css_set_hash(struct cgroup_subsys_state css[])
		static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
		{
		int i;
		int index;
		unsigned long tmp = 0UL;
		unsigned long key = 0UL;

		for (i = 0; i < CGROUP_SUBSYS_COUNT; i++)
		tmp += (unsigned long)css[i];
		tmp = (tmp >> 16) ^ tmp;
		key += (unsigned long)css[i];
		key = (key >> 16) ^ key;

		index = hash_long(tmp, CSS_SET_HASH_BITS);

		return &css_set_table[index];
		return key;
		}

		/* We don't maintain the lists running through each css_set to its
		@@ -418,7 +414,7 @@ static void __put_css_set(struct css_set *cg, int taskexit)
		}

		/* This css_set is dead. unlink it and release cgroup refcounts */
		hlist_del(&cg->hlist);
		hash_del(&cg->hlist);
		css_set_count--;

		list_for_each_entry_safe(link, saved_link, &cg->cg_links,
		@@ -550,9 +546,9 @@ static struct css_set *find_existing_css_set(
		{
		int i;
		struct cgroupfs_root *root = cgrp->root;
		struct hlist_head *hhead;
		struct hlist_node *node;
		struct css_set *cg;
		unsigned long key;

		/*
		* Build the set of subsystem state objects that we want to see in the
		@@ -572,8 +568,8 @@ static struct css_set *find_existing_css_set(
		}
		}

		hhead = css_set_hash(template);
		hlist_for_each_entry(cg, node, hhead, hlist) {
		key = css_set_hash(template);
		hash_for_each_possible(css_set_table, cg, node, hlist, key) {
		if (!compare_css_sets(cg, oldcg, cgrp, template))
		continue;

		@@ -657,8 +653,8 @@ static struct css_set *find_css_set(

		struct list_head tmp_cg_links;

		struct hlist_head *hhead;
		struct cg_cgroup_link *link;
		unsigned long key;

		/* First see if we already have a cgroup group that matches
		* the desired set */
		@@ -704,8 +700,8 @@ static struct css_set *find_css_set(
		css_set_count++;

		/* Add this cgroup group to the hash table */
		hhead = css_set_hash(res->subsys);
		hlist_add_head(&res->hlist, hhead);
		key = css_set_hash(res->subsys);
		hash_add(css_set_table, &res->hlist, key);

		write_unlock(&css_set_lock);

		@@ -1597,6 +1593,8 @@ static struct dentry cgroup_mount(struct file_system_type fs_type,
		struct cgroupfs_root *existing_root;
		const struct cred *cred;
		int i;
		struct hlist_node *node;
		struct css_set *cg;

		BUG_ON(sb->s_root != NULL);

		@@ -1650,14 +1648,8 @@ static struct dentry cgroup_mount(struct file_system_type fs_type,
		/* Link the top cgroup in this hierarchy into all
		* the css_set objects */
		write_lock(&css_set_lock);
		for (i = 0; i < CSS_SET_TABLE_SIZE; i++) {
		struct hlist_head *hhead = &css_set_table[i];
		struct hlist_node *node;
		struct css_set *cg;

		hlist_for_each_entry(cg, node, hhead, hlist)
		hash_for_each(css_set_table, i, node, cg, hlist)
		link_css_set(&tmp_cg_links, cg, root_cgrp);
		}
		write_unlock(&css_set_lock);

		free_cg_links(&tmp_cg_links);
		@@ -4464,6 +4456,9 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
		{
		struct cgroup_subsys_state *css;
		int i, ret;
		struct hlist_node node, tmp;
		struct css_set *cg;
		unsigned long key;

		/* check name and function validity */
		if (ss->name == NULL \|\| strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN \|\|
		@@ -4529,23 +4524,17 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
		* this is all done under the css_set_lock.
		*/
		write_lock(&css_set_lock);
		for (i = 0; i < CSS_SET_TABLE_SIZE; i++) {
		struct css_set *cg;
		struct hlist_node node, tmp;
		struct hlist_head bucket = &css_set_table[i], new_bucket;

		hlist_for_each_entry_safe(cg, node, tmp, bucket, hlist) {
		hash_for_each_safe(css_set_table, i, node, tmp, cg, hlist) {
		/* skip entries that we already rehashed */
		if (cg->subsys[ss->subsys_id])
		continue;
		/* remove existing entry */
		hlist_del(&cg->hlist);
		hash_del(&cg->hlist);
		/* set new value */
		cg->subsys[ss->subsys_id] = css;
		/* recompute hash and restore entry */
		new_bucket = css_set_hash(cg->subsys);
		hlist_add_head(&cg->hlist, new_bucket);
		}
		key = css_set_hash(cg->subsys);
		hash_add(css_set_table, node, key);
		}
		write_unlock(&css_set_lock);

		@@ -4577,7 +4566,6 @@ EXPORT_SYMBOL_GPL(cgroup_load_subsys);
		void cgroup_unload_subsys(struct cgroup_subsys *ss)
		{
		struct cg_cgroup_link *link;
		struct hlist_head *hhead;

		BUG_ON(ss->module == NULL);

		@@ -4611,11 +4599,12 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
		write_lock(&css_set_lock);
		list_for_each_entry(link, &dummytop->css_sets, cgrp_link_list) {
		struct css_set *cg = link->cg;
		unsigned long key;

		hlist_del(&cg->hlist);
		hash_del(&cg->hlist);
		cg->subsys[ss->subsys_id] = NULL;
		hhead = css_set_hash(cg->subsys);
		hlist_add_head(&cg->hlist, hhead);
		key = css_set_hash(cg->subsys);
		hash_add(css_set_table, &cg->hlist, key);
		}
		write_unlock(&css_set_lock);

		@@ -4657,9 +4646,6 @@ int __init cgroup_init_early(void)
		list_add(&init_css_set_link.cg_link_list,
		&init_css_set.cg_links);

		for (i = 0; i < CSS_SET_TABLE_SIZE; i++)
		INIT_HLIST_HEAD(&css_set_table[i]);

		for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
		struct cgroup_subsys *ss = subsys[i];

		@@ -4693,7 +4679,7 @@ int __init cgroup_init(void)
		{
		int err;
		int i;
		struct hlist_head *hhead;
		unsigned long key;

		err = bdi_init(&cgroup_backing_dev_info);
		if (err)
		@@ -4712,8 +4698,8 @@ int __init cgroup_init(void)
		}

		/* Add init_css_set to the hash table */
		hhead = css_set_hash(init_css_set.subsys);
		hlist_add_head(&init_css_set.hlist, hhead);
		key = css_set_hash(init_css_set.subsys);
		hash_add(css_set_table, &init_css_set.hlist, key);
		BUG_ON(!init_root_id(&rootnode));

		cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj);