From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753463AbdHQS0W (ORCPT ); Thu, 17 Aug 2017 14:26:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47880 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752614AbdHQSZy (ORCPT ); Thu, 17 Aug 2017 14:25:54 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 35495356DB Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=longman@redhat.com From: Waiman Long To: Tejun Heo , Li Zefan , Johannes Weiner Cc: linux-kernel@vger.kernel.org, Waiman Long Subject: [PATCH v2 1/2] cgroup: Add a hint to allow v1 controller to use v2 behavior Date: Thu, 17 Aug 2017 14:25:38 -0400 Message-Id: <1502994339-21668-2-git-send-email-longman@redhat.com> In-Reply-To: <1502994339-21668-1-git-send-email-longman@redhat.com> References: <1502994339-21668-1-git-send-email-longman@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 17 Aug 2017 18:25:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For some cgroup controllers, the behavior on cgroup v1 differs somewhat from cgroup v2. To indicate that a controller can use v2 behavior in cgroup v1, a new cgroupfs mount option "v2_mode" is added. This is essentially a hint, there is no obligation for a controller to comply with this semantics. Signed-off-by: Waiman Long --- include/linux/cgroup-defs.h | 5 +++++ kernel/cgroup/cgroup-v1.c | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 09f4c7d..fae33ed 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), + + /* + * A hint that v1 cgroup should use v2 behavior, if applicable. + */ + CGRP_ROOT_V2_MODE = (1 << 4), }; /* cftype->flags */ diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 7bf4b15..77e22a4 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -846,6 +846,8 @@ 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_V2_MODE) + seq_puts(seq, ",v2_mode"); spin_lock(&release_agent_path_lock); if (strlen(root->release_agent_path)) @@ -900,6 +902,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) opts->cpuset_clone_children = true; continue; } + if (!strcmp(token, "v2_mode")) { + opts->flags |= CGRP_ROOT_V2_MODE; + continue; + } if (!strcmp(token, "xattr")) { opts->flags |= CGRP_ROOT_XATTR; continue; -- 1.8.3.1