From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: [PATCH v8 2/7] cgroup: implement __cgroup_task_count() helper Date: Tue, 19 Feb 2019 14:02:47 -0800 Message-ID: <20190219220252.4906-3-guro@fb.com> References: <20190219220252.4906-1-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=UJ4P00vx6U5PVt2qTIPEjoDmQITn36JjYHqlVjlSqjo=; b=d/5TaA/K17ynBMaopcn3ZXeD/EuvctR/PrwWdbrG8MGBCzdztK/qOOdj0yHK/r1M9I XCfIgI1JX0fCkAPqI2VBCRGyKPP7QrnzZqBEgNGCwCUjJueBnTkl+DUxYAGgI1qMV02R xVNAO2i2REPTrWj7OwcqlZSi1DLRyYlvMn+aSjKlWfSJeL/UQwPWzKorDW9IJ7IiEA2F GTTd5BO9K+C9X56WlkJWo01FWmDPwnO2ibe9YGIm6LTVDPFenrR8LcYCVa47UtTusLPI APmVN2YkyFqU/PdsZI9mGX2zp/L/VpCRf0F+jT5W0NuM4hx7YH/yXbDfJSMIz/8p4JaR MjtQ== In-Reply-To: <20190219220252.4906-1-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 c950864016e2..a195328431ce 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -226,6 +226,7 @@ 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 583b969b0c0e..29c0ca8f76cf 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -339,22 +339,6 @@ 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 f4418371c83b..b230afccf635 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -592,6 +592,39 @@ 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