From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 1/3 cgroup/for-3.19] cgroup: add cgroup_subsys->css_released() Date: Mon, 17 Nov 2014 15:56:52 -0500 Message-ID: <20141117205652.GA23126@htj.dyndns.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; bh=elbFqBZ4l9iRs8W7EaikkurIQ/fDiqIsz3g+JKh8+f4=; b=ZiCAhzR/of9oZUe5tze0zn5TXNDCWyYUHdcMH0llxXfRthWSg2vsx91qlI92G5wAE1 Iij2CwTgTerbzLg/fhNBe4q0CzkwI7xq6cGUVZCvlEW3+ltynmt+0qKCUCE6ZvBPePXb wKE3I7MTwXTVsf9ypm0buFw6tdBL5TfTiMwkdhcM1rtxiEP4zyAj3NWbhkdAntPoBt4p A4nPPcgpW0aeLQPI+cxc155VFdW/V4FHc5xyAhi3dmbpkMjJbu1erOdA9nL9nlBylaH8 ZrMZmZQvd9/7fgN48ZWOhIlC7ssUhvWvtS8u7etRR4kh6pNypnYEaohl8bdiwWQlIw7U X1kg== Content-Disposition: inline Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Li Zefan Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Add a new cgroup subsys callback css_released(). This is called when the reference count of the css (cgroup_subsys_state) reaches zero before RCU scheduling free. Signed-off-by: Tejun Heo Cc: Li Zefan --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 2 ++ 2 files changed, 3 insertions(+) --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -612,6 +612,7 @@ struct cgroup_subsys { struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css); int (*css_online)(struct cgroup_subsys_state *css); void (*css_offline)(struct cgroup_subsys_state *css); + void (*css_released)(struct cgroup_subsys_state *css); void (*css_free)(struct cgroup_subsys_state *css); void (*css_reset)(struct cgroup_subsys_state *css); --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4380,6 +4380,8 @@ static void css_release_work_fn(struct w if (ss) { /* css release path */ cgroup_idr_remove(&ss->css_idr, css->id); + if (ss->css_released) + ss->css_released(css); } else { /* cgroup release path */ cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);