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From:   Waiman Long <longman@redhat.com>
To:     Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Shuah Khan <shuah@kernel.org>
Cc:     cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Peter Hunt <pehunt@redhat.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Waiman Long <longman@redhat.com>
Subject: [PATCH v4 1/5] workqueue: Make workqueue_set_unbound_cpumask() static
Date:   Wed, 15 Nov 2023 22:34:01 -0500
Message-Id: <20231116033405.185166-2-longman@redhat.com>
In-Reply-To: <20231116033405.185166-1-longman@redhat.com>
References: <20231116033405.185166-1-longman@redhat.com>
MIME-Version: 1.0
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The workqueue_set_unbound_cpumask() function is only used inside
workqueue.c with CONFIG_SYSFS. Make it static and move it down to
within the ifdef CONFIG_SYSFS block. Also move apply_wqattrs_lock()
and apply_wqattrs_unlock() down as all their callers are within the
CONFIG_SYSFS block.

Also mark workqueue_apply_unbound_cpumask() as __maybe_unused for now as
it will be used by another function introduced in a later commit. There
is no functional change.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 include/linux/workqueue.h |   1 -
 kernel/workqueue.c        | 102 +++++++++++++++++++-------------------
 2 files changed, 51 insertions(+), 52 deletions(-)

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 24b1e5070f4d..cf49b467bd57 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -491,7 +491,6 @@ struct workqueue_attrs *alloc_workqueue_attrs(void);
 void free_workqueue_attrs(struct workqueue_attrs *attrs);
 int apply_workqueue_attrs(struct workqueue_struct *wq,
 			  const struct workqueue_attrs *attrs);
-int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
 
 extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
 			struct work_struct *work);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 6e578f576a6f..145159f993e9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4411,19 +4411,6 @@ static void apply_wqattrs_commit(struct apply_wqattrs_ctx *ctx)
 	mutex_unlock(&ctx->wq->mutex);
 }
 
-static void apply_wqattrs_lock(void)
-{
-	/* CPUs should stay stable across pwq creations and installations */
-	cpus_read_lock();
-	mutex_lock(&wq_pool_mutex);
-}
-
-static void apply_wqattrs_unlock(void)
-{
-	mutex_unlock(&wq_pool_mutex);
-	cpus_read_unlock();
-}
-
 static int apply_workqueue_attrs_locked(struct workqueue_struct *wq,
 					const struct workqueue_attrs *attrs)
 {
@@ -5784,7 +5771,7 @@ void thaw_workqueues(void)
 }
 #endif /* CONFIG_FREEZER */
 
-static int workqueue_apply_unbound_cpumask(const cpumask_var_t unbound_cpumask)
+static int __maybe_unused workqueue_apply_unbound_cpumask(const cpumask_var_t unbound_cpumask)
 {
 	LIST_HEAD(ctxs);
 	int ret = 0;
@@ -5827,43 +5814,6 @@ static int workqueue_apply_unbound_cpumask(const cpumask_var_t unbound_cpumask)
 	return ret;
 }
 
-/**
- *  workqueue_set_unbound_cpumask - Set the low-level unbound cpumask
- *  @cpumask: the cpumask to set
- *
- *  The low-level workqueues cpumask is a global cpumask that limits
- *  the affinity of all unbound workqueues.  This function check the @cpumask
- *  and apply it to all unbound workqueues and updates all pwqs of them.
- *
- *  Return:	0	- Success
- *  		-EINVAL	- Invalid @cpumask
- *  		-ENOMEM	- Failed to allocate memory for attrs or pwqs.
- */
-int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
-{
-	int ret = -EINVAL;
-
-	/*
-	 * Not excluding isolated cpus on purpose.
-	 * If the user wishes to include them, we allow that.
-	 */
-	cpumask_and(cpumask, cpumask, cpu_possible_mask);
-	if (!cpumask_empty(cpumask)) {
-		apply_wqattrs_lock();
-		if (cpumask_equal(cpumask, wq_unbound_cpumask)) {
-			ret = 0;
-			goto out_unlock;
-		}
-
-		ret = workqueue_apply_unbound_cpumask(cpumask);
-
-out_unlock:
-		apply_wqattrs_unlock();
-	}
-
-	return ret;
-}
-
 static int parse_affn_scope(const char *val)
 {
 	int i;
@@ -5982,6 +5932,19 @@ static struct attribute *wq_sysfs_attrs[] = {
 };
 ATTRIBUTE_GROUPS(wq_sysfs);
 
+static void apply_wqattrs_lock(void)
+{
+	/* CPUs should stay stable across pwq creations and installations */
+	cpus_read_lock();
+	mutex_lock(&wq_pool_mutex);
+}
+
+static void apply_wqattrs_unlock(void)
+{
+	mutex_unlock(&wq_pool_mutex);
+	cpus_read_unlock();
+}
+
 static ssize_t wq_nice_show(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
@@ -6158,6 +6121,43 @@ static struct bus_type wq_subsys = {
 	.dev_groups			= wq_sysfs_groups,
 };
 
+/**
+ *  workqueue_set_unbound_cpumask - Set the low-level unbound cpumask
+ *  @cpumask: the cpumask to set
+ *
+ *  The low-level workqueues cpumask is a global cpumask that limits
+ *  the affinity of all unbound workqueues.  This function check the @cpumask
+ *  and apply it to all unbound workqueues and updates all pwqs of them.
+ *
+ *  Return:	0	- Success
+ *		-EINVAL	- Invalid @cpumask
+ *		-ENOMEM	- Failed to allocate memory for attrs or pwqs.
+ */
+static int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
+{
+	int ret = -EINVAL;
+
+	/*
+	 * Not excluding isolated cpus on purpose.
+	 * If the user wishes to include them, we allow that.
+	 */
+	cpumask_and(cpumask, cpumask, cpu_possible_mask);
+	if (!cpumask_empty(cpumask)) {
+		apply_wqattrs_lock();
+		if (cpumask_equal(cpumask, wq_unbound_cpumask)) {
+			ret = 0;
+			goto out_unlock;
+		}
+
+		ret = workqueue_apply_unbound_cpumask(cpumask);
+
+out_unlock:
+		apply_wqattrs_unlock();
+	}
+
+	return ret;
+}
+
 static ssize_t wq_unbound_cpumask_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-- 
2.39.3