diff options
author | Li Zefan <lizefan@huawei.com> | 2013-06-18 10:53:53 (GMT) |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2013-06-18 18:14:21 (GMT) |
commit | 794611a1dfcb055d7d41ce133378dd8197d73e38 (patch) | |
tree | c89867196b18237422fddf6c62862de08038838a /kernel/cgroup.c | |
parent | f57947d27711451a7739a25bba6cddc8a385e438 (diff) | |
download | linux-794611a1dfcb055d7d41ce133378dd8197d73e38.tar.xz |
cgroup: make serial_nr_cursor available throughout cgroup.c
The next patch will use it to determine if a cgroup is newly created
while we're iterating the cgroup hierarchy.
tj: Rephrased the comment on top of cgroup_serial_nr_cursor.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r-- | kernel/cgroup.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 1d4f471..e6571ca 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -198,6 +198,15 @@ static DEFINE_IDR(cgroup_hierarchy_idr); static struct cgroup_name root_cgroup_name = { .name = "/" }; +/* + * Assign a monotonically increasing serial number to cgroups. It + * guarantees cgroups with bigger numbers are newer than those with smaller + * numbers. Also, as cgroups are always appended to the parent's + * ->children list, it guarantees that sibling cgroups are always sorted in + * the ascending serial number order on the list. + */ +static atomic64_t cgroup_serial_nr_cursor = ATOMIC64_INIT(0); + /* This flag indicates whether tasks in the fork and exit paths should * check for fork/exit handlers to call. This avoids us having to do * extra work in the fork/exit path if none of the subsystems need to @@ -4222,7 +4231,6 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp) static long cgroup_create(struct cgroup *parent, struct dentry *dentry, umode_t mode) { - static atomic64_t serial_nr_cursor = ATOMIC64_INIT(0); struct cgroup *cgrp; struct cgroup_name *name; struct cgroupfs_root *root = parent->root; @@ -4309,13 +4317,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, goto err_free_all; lockdep_assert_held(&dentry->d_inode->i_mutex); - /* - * Assign a monotonically increasing serial number. With the list - * appending below, it guarantees that sibling cgroups are always - * sorted in the ascending serial number order on the parent's - * ->children. - */ - cgrp->serial_nr = atomic64_inc_return(&serial_nr_cursor); + cgrp->serial_nr = atomic64_inc_return(&cgroup_serial_nr_cursor); /* allocation complete, commit to creation */ list_add_tail(&cgrp->allcg_node, &root->allcg_list); |