3 files changed, 42 insertions, 5 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4cd1a5da80a4..32e9297ef747 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -375,6 +375,10 @@ and is between 256 and 4096 characters. It is defined in the file
         ccw_timeout_log [S390]
                         See Documentation/s390/CommonIO for details.
 
+        cgroup_disable= [KNL] Disable a particular controller
+                        Format: {name of the controller(s) to disable}
+                                {Currently supported controllers - "memory"}
+
         checkreqprot    [SELINUX] Set initial checkreqprot flag value.
                         Format: { "0" | "1" }
                         See security/selinux/Kconfig help text.
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 028ba3b523b1..a6a6035a4e1e 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -256,6 +256,7 @@ struct cgroup_subsys {
         void (*bind)(struct cgroup_subsys *ss, struct cgroup *root);
         int subsys_id;
         int active;
+        int disabled;
         int early_init;
 #define MAX_CGROUP_TYPE_NAMELEN 32
         const char *name;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 53d86b4b0ce0..62f1a5231fe9 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;
                                 }
                         }
@@ -2600,13 +2608,13 @@ 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;
@@ -3010,3 +3018,27 @@ 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);