cgroups: remove the css_set linked-list
Now we can run through the hash table instead of running through the
linked-list.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index f585b7c..d58a958 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -150,12 +150,6 @@
struct kref ref;
/*
- * List running through all cgroup groups. Protected by
- * css_set_lock
- */
- struct list_head list;
-
- /*
* List running through all cgroup groups in the same hash
* slot. Protected by css_set_lock
*/
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b893c8c..aeceb88 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -242,7 +242,6 @@
{
write_lock(&css_set_lock);
hlist_del(&cg->hlist);
- list_del(&cg->list);
css_set_count--;
while (!list_empty(&cg->cg_links)) {
struct cg_cgroup_link *link;
@@ -477,8 +476,6 @@
BUG_ON(!list_empty(&tmp_cg_links));
- /* Link this cgroup group into the list */
- list_add(&res->list, &init_css_set.list);
css_set_count++;
/* Add this cgroup group to the hash table */
@@ -963,7 +960,7 @@
int ret = 0;
struct super_block *sb;
struct cgroupfs_root *root;
- struct list_head tmp_cg_links, *l;
+ struct list_head tmp_cg_links;
INIT_LIST_HEAD(&tmp_cg_links);
/* First find the desired set of subsystems */
@@ -1005,6 +1002,7 @@
/* New superblock */
struct cgroup *cgrp = &root->top_cgroup;
struct inode *inode;
+ int i;
BUG_ON(sb->s_root != NULL);
@@ -1049,22 +1047,25 @@
/* Link the top cgroup in this hierarchy into all
* the css_set objects */
write_lock(&css_set_lock);
- l = &init_css_set.list;
- do {
+ 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;
- struct cg_cgroup_link *link;
- cg = list_entry(l, struct css_set, list);
- BUG_ON(list_empty(&tmp_cg_links));
- link = list_entry(tmp_cg_links.next,
- struct cg_cgroup_link,
- cgrp_link_list);
- list_del(&link->cgrp_link_list);
- link->cg = cg;
- list_add(&link->cgrp_link_list,
- &root->top_cgroup.css_sets);
- list_add(&link->cg_link_list, &cg->cg_links);
- l = l->next;
- } while (l != &init_css_set.list);
+
+ hlist_for_each_entry(cg, node, hhead, hlist) {
+ struct cg_cgroup_link *link;
+
+ BUG_ON(list_empty(&tmp_cg_links));
+ link = list_entry(tmp_cg_links.next,
+ struct cg_cgroup_link,
+ cgrp_link_list);
+ list_del(&link->cgrp_link_list);
+ link->cg = cg;
+ list_add(&link->cgrp_link_list,
+ &root->top_cgroup.css_sets);
+ list_add(&link->cg_link_list, &cg->cg_links);
+ }
+ }
write_unlock(&css_set_lock);
free_cg_links(&tmp_cg_links);
@@ -2514,7 +2515,6 @@
int i;
kref_init(&init_css_set.ref);
kref_get(&init_css_set.ref);
- INIT_LIST_HEAD(&init_css_set.list);
INIT_LIST_HEAD(&init_css_set.cg_links);
INIT_LIST_HEAD(&init_css_set.tasks);
INIT_HLIST_NODE(&init_css_set.hlist);