From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCHv1 3/8] cgroup: add function to get task's cgroup on default hierarchy Date: Thu, 16 Oct 2014 18:13:24 +0200 Message-ID: <20141016161324.GC1392@mail.hallyn.com> References: <1413235430-22944-1-git-send-email-adityakali@google.com> <1413235430-22944-4-git-send-email-adityakali@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1413235430-22944-4-git-send-email-adityakali-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Aditya Kali Cc: tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org, luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: linux-api@vger.kernel.org Quoting Aditya Kali (adityakali-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org): > get_task_cgroup() returns the (reference counted) cgroup of the > given task on the default hierarchy. > > Signed-off-by: Aditya Kali Acked-by: Serge Hallyn > --- > include/linux/cgroup.h | 1 + > kernel/cgroup.c | 25 +++++++++++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h > index 1d51968..80ed6e0 100644 > --- a/include/linux/cgroup.h > +++ b/include/linux/cgroup.h > @@ -579,6 +579,7 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp) > } > > char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); > +struct cgroup *get_task_cgroup(struct task_struct *task); > > int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); > int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index cab7dc4..56d507b 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -1916,6 +1916,31 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) > } > EXPORT_SYMBOL_GPL(task_cgroup_path); > > +/* > + * get_task_cgroup - returns the cgroup of the task in the default cgroup > + * hierarchy. > + * > + * @task: target task > + * This function returns the @task's cgroup on the default cgroup hierarchy. The > + * returned cgroup has its reference incremented (by calling cgroup_get()). So > + * the caller must cgroup_put() the obtained reference once it is done with it. > + */ > +struct cgroup *get_task_cgroup(struct task_struct *task) > +{ > + struct cgroup *cgrp; > + > + mutex_lock(&cgroup_mutex); > + down_read(&css_set_rwsem); > + > + cgrp = task_cgroup_from_root(task, &cgrp_dfl_root); > + cgroup_get(cgrp); > + > + up_read(&css_set_rwsem); > + mutex_unlock(&cgroup_mutex); > + return cgrp; > +} > +EXPORT_SYMBOL_GPL(get_task_cgroup); > + > /* used to track tasks and other necessary states during migration */ > struct cgroup_taskset { > /* the src and dst cset list running through cset->mg_node */ > -- > 2.1.0.rc2.206.gedb03e5 > > _______________________________________________ > Containers mailing list > Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/containers