cgroup: s/CGRP_CLONE_CHILDREN/CGRP_CPUSET_CLONE_CHILDREN/

clone_children is only meaningful for cpuset and will stay that way.
Rename the flag to reflect that and update documentation.  Also, drop
clone_children() wrapper in cgroup.c.  The thin wrapper is used only a
few times and one of them will go away soon.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Glauber Costa <glommer@parallels.com>

diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index b06eea2..24cdf76 100644 (file)
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -299,11 +299,9 @@ a cgroup hierarchy's release_agent path is empty.
 1.5 What does clone_children do ?
 ---------------------------------
 
-If the clone_children flag is enabled (1) in a cgroup, then all
-cgroups created beneath will call the post_clone callbacks for each
-subsystem of the newly created cgroup. Usually when this callback is
-implemented for a subsystem, it copies the values of the parent
-subsystem, this is the case for the cpuset.
+This flag only affects the cpuset controller. If the clone_children
+flag is enabled (1) in a cgroup, a new cpuset cgroup will copy its
+configuration from the parent during initialization.
 
 1.6 How do I use cgroups ?
 --------------------------

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 7a2189c..d2f8297 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -143,9 +143,11 @@ enum {
        /* Control Group requires release notifications to userspace */
        CGRP_NOTIFY_ON_RELEASE,
        /*
-        * Clone cgroup values when creating a new child cgroup
+        * Clone the parent's configuration when creating a new child
+        * cpuset cgroup.  For historical reasons, this option can be
+        * specified at mount time and thus is implemented here.
         */
-       CGRP_CLONE_CHILDREN,
+       CGRP_CPUSET_CLONE_CHILDREN,
 };
 
 struct cgroup {

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d35463b..2895880 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -296,11 +296,6 @@ static int notify_on_release(const struct cgroup *cgrp)
        return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
 }
 
-static int clone_children(const struct cgroup *cgrp)
-{
-       return test_bit(CGRP_CLONE_CHILDREN, &cgrp->flags);
-}
-
 /*
  * for_each_subsys() allows you to iterate on each subsystem attached to
  * an active hierarchy
@@ -1101,7 +1096,7 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry)
                seq_puts(seq, ",xattr");
        if (strlen(root->release_agent_path))
                seq_printf(seq, ",release_agent=%s", root->release_agent_path);
-       if (clone_children(&root->top_cgroup))
+       if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->top_cgroup.flags))
                seq_puts(seq, ",clone_children");
        if (strlen(root->name))
                seq_printf(seq, ",name=%s", root->name);
@@ -1113,7 +1108,7 @@ struct cgroup_sb_opts {
        unsigned long subsys_mask;
        unsigned long flags;
        char *release_agent;
-       bool clone_children;
+       bool cpuset_clone_children;
        char *name;
        /* User explicitly requested empty subsystem */
        bool none;
@@ -1164,7 +1159,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                        continue;
                }
                if (!strcmp(token, "clone_children")) {
-                       opts->clone_children = true;
+                       opts->cpuset_clone_children = true;
                        continue;
                }
                if (!strcmp(token, "xattr")) {
@@ -1474,8 +1469,8 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
                strcpy(root->release_agent_path, opts->release_agent);
        if (opts->name)
                strcpy(root->name, opts->name);
-       if (opts->clone_children)
-               set_bit(CGRP_CLONE_CHILDREN, &root->top_cgroup.flags);
+       if (opts->cpuset_clone_children)
+               set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->top_cgroup.flags);
        return root;
 }
 
@@ -3905,7 +3900,7 @@ fail:
 static u64 cgroup_clone_children_read(struct cgroup *cgrp,
                                    struct cftype *cft)
 {
-       return clone_children(cgrp);
+       return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
 }
 
 static int cgroup_clone_children_write(struct cgroup *cgrp,
@@ -3913,9 +3908,9 @@ static int cgroup_clone_children_write(struct cgroup *cgrp,
                                     u64 val)
 {
        if (val)
-               set_bit(CGRP_CLONE_CHILDREN, &cgrp->flags);
+               set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
        else
-               clear_bit(CGRP_CLONE_CHILDREN, &cgrp->flags);
+               clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
        return 0;
 }
 
@@ -4130,8 +4125,8 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
        if (notify_on_release(parent))
                set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
 
-       if (clone_children(parent))
-               set_bit(CGRP_CLONE_CHILDREN, &cgrp->flags);
+       if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &parent->flags))
+               set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
 
        for_each_subsys(root, ss) {
                struct cgroup_subsys_state *css;
@@ -4148,7 +4143,8 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
                                goto err_free_all;
                }
                /* At error, ->css_free() callback has to free assigned ID. */
-               if (clone_children(parent) && ss->post_clone)
+               if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &parent->flags) &&
+                   ss->post_clone)
                        ss->post_clone(cgrp);
 
                if (ss->broken_hierarchy && !ss->warned_broken_hierarchy &&