cgroup: remove the css_set linked-list

PATCH In review Li Zefan 3 participants 3 messages Apr 3, 2008 1 message not in the archive cgroup

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Li Zefan

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2008-04-03 05:55 UTC #0 lore raw

PATCH 3/3 cgroup: 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 <[email protected]>

---
 include/linux/cgroup.h |    6 ------
 kernel/cgroup.c        |   40 ++++++++++++++++++++--------------------
 2 files changed, 20 insertions(+), 26 deletions(-)

include/linux/cgroup.h +0 -6

index f585b7c..d58a958 100644
@@ -150,12 +150,6 @@ struct css_set {
 	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
 	 */

kernel/cgroup.c +20 ~~-20~~

index 250e28e..9e7cf16 100644
@@ -241,7 +241,6 @@ static void unlink_css_set(struct css_set *cg)
 {
 	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;

@@ -476,8 +475,6 @@ static struct css_set *find_css_set(
 
 	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 */

@@ -962,7 +959,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 	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 */

@@ -1004,6 +1001,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 		/* New superblock */
 		struct cgroup *cgrp = &root->top_cgroup;
 		struct inode *inode;
+		int i;
 
 		BUG_ON(sb->s_root != NULL);

@@ -1048,22 +1046,25 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 		/* 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);

@@ -2508,7 +2509,6 @@ int __init cgroup_init_early(void)
 	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);

Signature · 1 line

1.5.4.rc3

A message that is not in the archive (sent off-list or not yet received): [email protected]

Paul Menage

Reviewed-by

2008-04-03 17:41 UTC #2 lore raw

Quoted 4 lines · Li Zefan

Now we can run through the hash table instead of running through
the linked-list.
Signed-off-by Li Zefan <[email protected]>

Reviewed-by Paul Menage <[email protected]>

Looks good, thanks.

Quoted 112 lines

---

  include/linux/cgroup.h |    6 ------
  kernel/cgroup.c        |   40 ++++++++++++++++++++--------------------
  2 files changed, 20 insertions(+), 26 deletions(-)

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 css_set {
        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 250e28e..9e7cf16 100644
 --- a/kernel/cgroup.c
 +++ b/kernel/cgroup.c
 @@ -241,7 +241,6 @@ static void unlink_css_set(struct css_set *cg)
  {
        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;

@@ -476,8 +475,6 @@ static struct css_set *find_css_set(

        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 */
 @@ -962,7 +959,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
        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 */
 @@ -1004,6 +1001,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                /* New superblock */
                struct cgroup *cgrp = &root->top_cgroup;
                struct inode *inode;

+ int i;

                BUG_ON(sb->s_root != NULL);

@@ -1048,22 +1046,25 @@ static int cgroup_get_sb(struct file_system_type *fs_type,

                /* 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);
 @@ -2508,7 +2509,6 @@ int __init cgroup_init_early(void)
        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);

--
1.5.4.rc3