cgroup, cpuset: remove cgroup_subsys->post_clone()

[karo-tx-linux.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f33c7153b6d7acea3752d7601275681b1afc23cd..b017887d632f21a7743882705b59b9d99b0add9d 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1784,56 +1784,20 @@ static struct cftype files[] = {
 };
 
 /*
- * post_clone() is called during cgroup_create() when the
- * clone_children mount argument was specified.  The cgroup
- * can not yet have any tasks.
- *
- * Currently we refuse to set up the cgroup - thereby
- * refusing the task to be entered, and as a result refusing
- * the sys_unshare() or clone() which initiated it - if any
- * sibling cpusets have exclusive cpus or mem.
- *
- * If this becomes a problem for some users who wish to
- * allow that scenario, then cpuset_post_clone() could be
- * changed to grant parent->cpus_allowed-sibling_cpus_exclusive
- * (and likewise for mems) to the new cgroup. Called with cgroup_mutex
- * held.
- */
-static void cpuset_post_clone(struct cgroup *cgroup)
-{
-       struct cgroup *parent, *child;
-       struct cpuset *cs, *parent_cs;
-
-       parent = cgroup->parent;
-       list_for_each_entry(child, &parent->children, sibling) {
-               cs = cgroup_cs(child);
-               if (is_mem_exclusive(cs) || is_cpu_exclusive(cs))
-                       return;
-       }
-       cs = cgroup_cs(cgroup);
-       parent_cs = cgroup_cs(parent);
-
-       mutex_lock(&callback_mutex);
-       cs->mems_allowed = parent_cs->mems_allowed;
-       cpumask_copy(cs->cpus_allowed, parent_cs->cpus_allowed);
-       mutex_unlock(&callback_mutex);
-       return;
-}
-
-/*
- *     cpuset_create - create a cpuset
+ *     cpuset_css_alloc - allocate a cpuset css
  *     cont:   control group that the new cpuset will be part of
  */
 
-static struct cgroup_subsys_state *cpuset_create(struct cgroup *cont)
+static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
 {
-       struct cpuset *cs;
-       struct cpuset *parent;
+       struct cgroup *parent_cg = cont->parent;
+       struct cgroup *tmp_cg;
+       struct cpuset *parent, *cs;
 
-       if (!cont->parent) {
+       if (!parent_cg)
                return &top_cpuset.css;
-       }
-       parent = cgroup_cs(cont->parent);
+       parent = cgroup_cs(parent_cg);
+
        cs = kmalloc(sizeof(*cs), GFP_KERNEL);
        if (!cs)
                return ERR_PTR(-ENOMEM);
@@ -1855,7 +1819,36 @@ static struct cgroup_subsys_state *cpuset_create(struct cgroup *cont)
 
        cs->parent = parent;
        number_of_cpusets++;
-       return &cs->css ;
+
+       if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cont->flags))
+               goto skip_clone;
+
+       /*
+        * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is
+        * set.  This flag handling is implemented in cgroup core for
+        * histrical reasons - the flag may be specified during mount.
+        *
+        * Currently, if any sibling cpusets have exclusive cpus or mem, we
+        * refuse to clone the configuration - thereby refusing the task to
+        * be entered, and as a result refusing the sys_unshare() or
+        * clone() which initiated it.  If this becomes a problem for some
+        * users who wish to allow that scenario, then this could be
+        * changed to grant parent->cpus_allowed-sibling_cpus_exclusive
+        * (and likewise for mems) to the new cgroup.
+        */
+       list_for_each_entry(tmp_cg, &parent_cg->children, sibling) {
+               struct cpuset *tmp_cs = cgroup_cs(tmp_cg);
+
+               if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs))
+                       goto skip_clone;
+       }
+
+       mutex_lock(&callback_mutex);
+       cs->mems_allowed = parent->mems_allowed;
+       cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
+       mutex_unlock(&callback_mutex);
+skip_clone:
+       return &cs->css;
 }
 
 /*
@@ -1864,7 +1857,7 @@ static struct cgroup_subsys_state *cpuset_create(struct cgroup *cont)
  * will call async_rebuild_sched_domains().
  */
 
-static void cpuset_destroy(struct cgroup *cont)
+static void cpuset_css_free(struct cgroup *cont)
 {
        struct cpuset *cs = cgroup_cs(cont);
 
@@ -1878,11 +1871,10 @@ static void cpuset_destroy(struct cgroup *cont)
 
 struct cgroup_subsys cpuset_subsys = {
        .name = "cpuset",
-       .create = cpuset_create,
-       .destroy = cpuset_destroy,
+       .css_alloc = cpuset_css_alloc,
+       .css_free = cpuset_css_free,
        .can_attach = cpuset_can_attach,
        .attach = cpuset_attach,
-       .post_clone = cpuset_post_clone,
        .subsys_id = cpuset_subsys_id,
        .base_cftypes = files,
        .early_init = 1,