From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: [PATCH v2 2/6] cgroup: implement __cgroup_task_count() helper Date: Mon, 12 Nov 2018 15:04:18 -0800 Message-ID: <20181112230422.5911-4-guro@fb.com> References: <20181112230422.5911-1-guro@fb.com> 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; bh=FP20pGgu3D25STEzu2nQYXaFb5vqYhGB0+bCEyu/01c=; b=gYj4+QLLPEksUSiryQwvQyfZONhBhGfmUh6aioSQOgcZxDkws2ECAoGpjf/mp/Nbxr KPARXI8utFVk1kJaUtwb3VxjhHO4OJzsCDBhLN0sdIIJ1AQ49ulu+9Qw7yDo5R2Wj2Ph nNrZ24JgzwwK0O8lrvif9dZ4PVotn32doQl23DdWJ29gLWXeujl2ol6Y1lMQW+JnqKWk AopiBCgKrtdHzGGHEIugqmwW0f/+uVRM7lJzJ4KCyOX4xW/Rv+J3+y8HihBX/lh+Kdt/ YcZ4ow5oHeZqFGJZV5FBmy4apL0w4PTmLhrQ7UfnAyfyGQWFSzJJkWF/9rr6RTw0dwFE 09tA== In-Reply-To: <20181112230422.5911-1-guro@fb.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: Oleg Nesterov , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, 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 75568fcf2180..fe01a9fa4a8d 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -224,6 +224,7 @@ 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 51063e7a93c2..6134fef07d57 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -336,22 +336,6 @@ 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 4a3dae2a8283..ef3442555b32 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -561,6 +561,39 @@ 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; -- 2.17.2