1 files changed, 40 insertions, 7 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e9c2fb01e89b..2727f9238359 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -782,7 +782,14 @@ static int parse_cgroupfs_options(char *data,
 		if (!*token)
 			return -EINVAL;
 		if (!strcmp(token, "all")) {
-			opts->subsys_bits = (1 << CGROUP_SUBSYS_COUNT) - 1;
+			/* Add all non-disabled subsystems */
+			int i;
+			opts->subsys_bits = 0;
+			for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+				struct cgroup_subsys *ss = subsys[i];
+				if (!ss->disabled)
+					opts->subsys_bits |= 1ul << i;
+			}
 		} else if (!strcmp(token, "noprefix")) {
 			set_bit(ROOT_NOPREFIX, &opts->flags);
 		} else if (!strncmp(token, "release_agent=", 14)) {
@@ -800,7 +807,8 @@ static int parse_cgroupfs_options(char *data,
 			for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 				ss = subsys[i];
 				if (!strcmp(token, ss->name)) {
-					set_bit(i, &opts->subsys_bits);
+					if (!ss->disabled)
+						set_bit(i, &opts->subsys_bits);
 					break;
 				}
 			}
@@ -2082,7 +2090,7 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file)
 
 		kfree(pidarray);
 	} else {
-		ctr->buf = 0;
+		ctr->buf = NULL;
 		ctr->bufsz = 0;
 	}
 	file->private_data = ctr;
@@ -2561,6 +2569,7 @@ static int proc_cgroup_show(struct seq_file *m, void *v)
 		/* Skip this hierarchy if it has no active subsystems */
 		if (!root->actual_subsys_bits)
 			continue;
+		seq_printf(m, "%lu:", root->subsys_bits);
 		for_each_subsys(root, ss)
 			seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
 		seq_putc(m, ':');
@@ -2600,13 +2609,13 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 {
 	int i;
 
-	seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\n");
+	seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
 	mutex_lock(&cgroup_mutex);
 	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 		struct cgroup_subsys *ss = subsys[i];
-		seq_printf(m, "%s\t%lu\t%d\n",
+		seq_printf(m, "%s\t%lu\t%d\t%d\n",
 			   ss->name, ss->root->subsys_bits,
-			   ss->root->number_of_cgroups);
+			   ss->root->number_of_cgroups, !ss->disabled);
 	}
 	mutex_unlock(&cgroup_mutex);
 	return 0;
@@ -2614,7 +2623,7 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 
 static int cgroupstats_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, proc_cgroupstats_show, 0);
+	return single_open(file, proc_cgroupstats_show, NULL);
 }
 
 static struct file_operations proc_cgroupstats_operations = {
@@ -3010,3 +3019,27 @@ static void cgroup_release_agent(struct work_struct *work)
 	spin_unlock(&release_list_lock);
 	mutex_unlock(&cgroup_mutex);
 }
+
+static int __init cgroup_disable(char *str)
+{
+	int i;
+	char *token;
+
+	while ((token = strsep(&str, ",")) != NULL) {
+		if (!*token)
+			continue;
+
+		for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+			struct cgroup_subsys *ss = subsys[i];
+
+			if (!strcmp(token, ss->name)) {
+				ss->disabled = 1;
+				printk(KERN_INFO "Disabling %s control group"
+					" subsystem\n", ss->name);
+				break;
+			}
+		}
+	}
+	return 1;
+}
+__setup("cgroup_disable=", cgroup_disable);