From: Waiman Long <longman@redhat.com>
Date: Thu, 17 Aug 2017 19:33:09 +0000 (-0400)
Subject: cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup
X-Git-Tag: v4.14-rc1~123^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e1cba4b85daa71b710384d451ff6238d5e4d1ff6;p=platform%2Fkernel%2Flinux-rpi.git

cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup

A new mount option "cpuset_v2_mode" is added to the v1 cgroupfs
filesystem to enable cpuset controller to use v2 behavior in a v1
cgroup. This mount option applies only to cpuset controller and have
no effect on other controllers.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 59e4ad9..ade4a78 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -74,6 +74,11 @@ enum {
 	 * aren't writeable from inside the namespace.
 	 */
 	CGRP_ROOT_NS_DELEGATE	= (1 << 3),
+
+	/*
+	 * Enable cpuset controller in v1 cgroup to use v2 behavior.
+	 */
+	CGRP_ROOT_CPUSET_V2_MODE = (1 << 4),
 };
 
 /* cftype->flags */
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index f0e8601..024085d 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -895,6 +895,8 @@ static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_roo
 		seq_puts(seq, ",noprefix");
 	if (root->flags & CGRP_ROOT_XATTR)
 		seq_puts(seq, ",xattr");
+	if (root->flags & CGRP_ROOT_CPUSET_V2_MODE)
+		seq_puts(seq, ",cpuset_v2_mode");
 
 	spin_lock(&release_agent_path_lock);
 	if (strlen(root->release_agent_path))
@@ -949,6 +951,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 			opts->cpuset_clone_children = true;
 			continue;
 		}
+		if (!strcmp(token, "cpuset_v2_mode")) {
+			opts->flags |= CGRP_ROOT_CPUSET_V2_MODE;
+			continue;
+		}
 		if (!strcmp(token, "xattr")) {
 			opts->flags |= CGRP_ROOT_XATTR;
 			continue;