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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 10:52:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 10:52:28 -0700
commit68d47a137c3bef754923bccf73fb639c9b0bbd5e (patch)
treee82a527bd978ee96283f03d0df36f47d9aee1e41 /kernel
parentc0e8a139a5bb8add02b4111e9e1957d810d7285e (diff)
parent8c7f6edbda01f1b1a2e60ad61f14fe38023e433b (diff)
Merge branch 'for-3.7-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup hierarchy update from Tejun Heo: "Currently, different cgroup subsystems handle nested cgroups completely differently. There's no consistency among subsystems and the behaviors often are outright broken. People at least seem to agree that the broken hierarhcy behaviors need to be weeded out if any progress is gonna be made on this front and that the fallouts from deprecating the broken behaviors should be acceptable especially given that the current behaviors don't make much sense when nested. This patch makes cgroup emit warning messages if cgroups for subsystems with broken hierarchy behavior are nested to prepare for fixing them in the future. This was put in a separate branch because more related changes were expected (didn't make it this round) and the memory cgroup wanted to pull in this and make changes on top." * 'for-3.7-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c12
-rw-r--r--kernel/cgroup_freezer.c8
-rw-r--r--kernel/events/core.c7
3 files changed, 26 insertions, 1 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 485cc1487ea2..13774b3b39aa 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4076,8 +4076,9 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
set_bit(CGRP_CLONE_CHILDREN, &cgrp->flags);
for_each_subsys(root, ss) {
- struct cgroup_subsys_state *css = ss->create(cgrp);
+ struct cgroup_subsys_state *css;
+ css = ss->create(cgrp);
if (IS_ERR(css)) {
err = PTR_ERR(css);
goto err_destroy;
@@ -4091,6 +4092,15 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
/* At error, ->destroy() callback has to free assigned ID. */
if (clone_children(parent) && ss->post_clone)
ss->post_clone(cgrp);
+
+ if (ss->broken_hierarchy && !ss->warned_broken_hierarchy &&
+ parent->parent) {
+ pr_warning("cgroup: %s (%d) created nested cgroup for controller \"%s\" which has incomplete hierarchy support. Nested cgroups may change behavior in the future.\n",
+ current->comm, current->pid, ss->name);
+ if (!strcmp(ss->name, "memory"))
+ pr_warning("cgroup: \"memory\" requires setting use_hierarchy to 1 on the root.\n");
+ ss->warned_broken_hierarchy = true;
+ }
}
list_add(&cgrp->sibling, &cgrp->parent->children);
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 3649fc6b3eaa..b1724ce98981 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -373,4 +373,12 @@ struct cgroup_subsys freezer_subsys = {
.can_attach = freezer_can_attach,
.fork = freezer_fork,
.base_cftypes = files,
+
+ /*
+ * freezer subsys doesn't handle hierarchy at all. Frozen state
+ * should be inherited through the hierarchy - if a parent is
+ * frozen, all its children should be frozen. Fix it and remove
+ * the following.
+ */
+ .broken_hierarchy = true,
};
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7b9df353ba1b..deec4e50eb30 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7503,5 +7503,12 @@ struct cgroup_subsys perf_subsys = {
.destroy = perf_cgroup_destroy,
.exit = perf_cgroup_exit,
.attach = perf_cgroup_attach,
+
+ /*
+ * perf_event cgroup doesn't handle nesting correctly.
+ * ctx->nr_cgroups adjustments should be propagated through the
+ * cgroup hierarchy. Fix it and remove the following.
+ */
+ .broken_hierarchy = true,
};
#endif /* CONFIG_CGROUP_PERF */