From b0ca5a84fc3ad8f75bb2b7ac3dc6a77151cd3906 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 1 Apr 2012 12:09:54 -0700 Subject: [PATCH] cgroup: build list of all cgroups under a given cgroupfs_root Build a list of all cgroups anchored at cgroupfs_root->allcg_list and going through cgroup->allcg_node. The list is protected by cgroup_mutex and will be used to improve cgroup file handling. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- include/linux/cgroup.h | 2 ++ kernel/cgroup.c | 10 ++++++++++ 2 files changed, 12 insertions(+) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 5a85b3415c1b..ad2a14680b7f 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -191,6 +191,8 @@ struct cgroup { */ struct list_head css_sets; + struct list_head allcg_node; /* cgroupfs_root->allcg_list */ + /* * Linked list running through all cgroups that can * potentially be reaped by the release agent. Protected by diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8f72853131d3..db4319c030d0 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -127,6 +127,9 @@ struct cgroupfs_root { /* A list running through the active hierarchies */ struct list_head root_list; + /* All cgroups on this root, cgroup_mutex protected */ + struct list_head allcg_list; + /* Hierarchy-specific flags */ unsigned long flags; @@ -1350,11 +1353,14 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; + INIT_LIST_HEAD(&root->subsys_list); INIT_LIST_HEAD(&root->root_list); + INIT_LIST_HEAD(&root->allcg_list); root->number_of_cgroups = 1; cgrp->root = root; cgrp->top_cgroup = cgrp; + list_add_tail(&cgrp->allcg_node, &root->allcg_list); init_cgroup_housekeeping(cgrp); } @@ -3790,6 +3796,8 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, /* The cgroup directory was pre-locked for us */ BUG_ON(!mutex_is_locked(&cgrp->dentry->d_inode->i_mutex)); + list_add_tail(&cgrp->allcg_node, &root->allcg_list); + err = cgroup_populate_dir(cgrp); /* If err < 0, we have a half-filled directory - oh well ;) */ @@ -3998,6 +4006,8 @@ again: list_del_init(&cgrp->sibling); cgroup_unlock_hierarchy(cgrp->root); + list_del_init(&cgrp->allcg_node); + d = dget(cgrp->dentry); cgroup_d_remove_dir(d); -- 2.30.2