From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: [PATCH v10 2/9] cgroup: implement __cgroup_task_count() helper Date: Fri, 5 Apr 2019 10:47:01 -0700 Message-ID: <20190405174708.1010-3-guro@fb.com> References: <20190405174708.1010-1-guro@fb.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=pj7WA03mP3oNwX6qE6zfP09vbwa2yYIzNAhT0cJRXXI=; b=kYX37Q7YMZBgxmmbjJ7RHh/xcKkq99Q4b0sjfszkujTyvZ5yvOK8+qX7ntFiKc36QT T3Ht34RWF++R3ZKcnSJNmkSuVNoDC5rHFvgFQwUJNwIEjkK/sZOg2frsrQ5AZ8zderS3 Y87Wcz8BWnUz2mdvhy0wemDgNfVMQiFnkNNRE1R3OOdA+WHfb8xg7oYMhYaqbRHUUbiB CJh545kflaMiipWQQL2IvlKSpk+sxcmEQBsHgnLWkIFtAVmDiwc1FaR6sfTvIue8rL8g eL9RkjHqlcYE/oZ8XWoEXFf76o0OpoeeL97KPM5a7dGTk6Nb+U/osL9fVzuyIqF192Na gmVQ== In-Reply-To: <20190405174708.1010-1-guro@fb.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo , Oleg Nesterov Cc: kernel-team@fb.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Roman Gushchin The helper is identical to the existing cgroup_task_count() except it doesn't take the css_set_lock by itself, assuming that the caller does. Also, move cgroup_task_count() implementation into kernel/cgroup/cgroup.c, as there is nothing specific to cgroup v1. Signed-off-by: Roman Gushchin Cc: Tejun Heo Cc: kernel-team@fb.com --- kernel/cgroup/cgroup-internal.h | 1 + kernel/cgroup/cgroup-v1.c | 16 ---------------- kernel/cgroup/cgroup.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 16 deletions(-) diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 30e39f3932ad..02c001ffe2e2 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -240,6 +240,7 @@ int cgroup_rmdir(struct kernfs_node *kn); int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, struct kernfs_root *kf_root); +int __cgroup_task_count(const struct cgroup *cgrp); int cgroup_task_count(const struct cgroup *cgrp); /* diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index c126b34fd4ff..68ca5de7ec27 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -342,22 +342,6 @@ static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp, return l; } -/** - * cgroup_task_count - count the number of tasks in a cgroup. - * @cgrp: the cgroup in question - */ -int cgroup_task_count(const struct cgroup *cgrp) -{ - int count = 0; - struct cgrp_cset_link *link; - - spin_lock_irq(&css_set_lock); - list_for_each_entry(link, &cgrp->cset_links, cset_link) - count += link->cset->nr_tasks; - spin_unlock_irq(&css_set_lock); - return count; -} - /* * Load a cgroup's pidarray with either procs' tgids or tasks' pids */ diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index f219c195a9a5..3008ea684aa0 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -593,6 +593,39 @@ static void cgroup_get_live(struct cgroup *cgrp) css_get(&cgrp->self); } +/** + * __cgroup_task_count - count the number of tasks in a cgroup. The caller + * is responsible for taking the css_set_lock. + * @cgrp: the cgroup in question + */ +int __cgroup_task_count(const struct cgroup *cgrp) +{ + int count = 0; + struct cgrp_cset_link *link; + + lockdep_assert_held(&css_set_lock); + + list_for_each_entry(link, &cgrp->cset_links, cset_link) + count += link->cset->nr_tasks; + + return count; +} + +/** + * cgroup_task_count - count the number of tasks in a cgroup. + * @cgrp: the cgroup in question + */ +int cgroup_task_count(const struct cgroup *cgrp) +{ + int count; + + spin_lock_irq(&css_set_lock); + count = __cgroup_task_count(cgrp); + spin_unlock_irq(&css_set_lock); + + return count; +} + struct cgroup_subsys_state *of_css(struct kernfs_open_file *of) { struct cgroup *cgrp = of->kn->parent->priv; -- 2.20.1