From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] cgroup: Show control files in cgroup2 root after mount Date: Tue, 18 Jul 2017 16:12:29 -0400 Message-ID: <20170718201229.GD3365493@devbig577.frc2.facebook.com> References: <1500406336-29512-1-git-send-email-longman@redhat.com> <20170718195148.GC3365493@devbig577.frc2.facebook.com> <539870d2-8b85-2f54-61bd-4ba068e75ce0@redhat.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Wea47tv++VVFzlOP1LLyoQTa36gJaAZeQVttupwGo24=; b=jJdvJR/VyIV9ExeOFP6YFrzE/Hq5hpPa9Hf72IFJgULNWqvW6T3cQBfUMawOV1WTpB p5Cp9z6rzJcYRUaP5BJ1DEI31wFSy7O0zmHwkJYiYQRL8lxaT34DXunM/f4q4mcj2rT7 5cbEa/T8gy0XsAqqObJnMPjxgiJDmAkRSebO6uhMBtYuX7gtNLuCjDnLcPX8PYcQIOIQ ACMSWutzrJ7ttV+nQJZlfAzHagnYlGe6nDQnspsOzAIhb2TF3/lkGC+g7GieWfuhy3rH gke1+3fp7vxuML1dVdzZ9YEU7lodUSsKpYeFjp3iaPU0LXwjIzT2MFGrWxyC7GyOWHE2 oPTQ== Content-Disposition: inline In-Reply-To: <539870d2-8b85-2f54-61bd-4ba068e75ce0-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Waiman Long Cc: Li Zefan , Johannes Weiner , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Hello, On Tue, Jul 18, 2017 at 04:00:45PM -0400, Waiman Long wrote: > From my own debugging, the controller files (e.g. the debug controller) > were indirectly populated by the rebind_subsystems() call. > > [ 1.628103] css_populate_dir: init subsystem debug ... > [ 1.654975] cgroup_apply_control_enable+0x103/0x340 > [ 1.657719] cgroup_apply_control+0x1a/0x30 > [ 1.658521] rebind_subsystems+0x18a/0x3b0 ... But there's kernfs_activate() call at the end of rebind_subsystems(), so if the files were being added there, it should have been activated there and I can confirm that the files are correctly added / removed from the cgroup2 root directory when controllers are attached to / detached from it. > For the default cgroup2 root, kernfs_activate() was only called at the > beginning in cgroup_init() with only the base cgroup files added. No > more call after that until I touched the cgroup.subtree_control file. Hmm... we're activating at the end of * cgroup_setup_root() * rebind_subsystems() * cgroup_subtree_control_write() * cgroup_apply_cftypes() after successful addition * cgroup_mkdir() I *think* this should cover everything. Just in case, are you looking at the mainline kernel? Can you share how you can reproduce the issue? Thanks. -- tejun