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Sender: Tejun Heo <htejun@gmail.com>
From: Tejun Heo <tj@kernel.org>
To: jiangshanlai@gmail.com
Cc: torvalds@linux-foundation.org,
	linux-kernel@vger.kernel.org,
	allen.lkml@gmail.com,
	kernel-team@meta.com,
	Tejun Heo <tj@kernel.org>
Subject: [PATCH 05/17] workqueue: Use variable name irq_flags for saving local irq flags
Date: Fri, 16 Feb 2024 08:04:46 -1000
Message-ID: <20240216180559.208276-6-tj@kernel.org>
In-Reply-To: <20240216180559.208276-1-tj@kernel.org>
References: <20240216180559.208276-1-tj@kernel.org>
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Using the generic term `flags` for irq flags is conventional but can be
confusing as there's quite a bit of code dealing with work flags which
involves some subtleties. Let's use a more explicit name `irq_flags` for
local irq flags. No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/workqueue.c | 76 +++++++++++++++++++++++-----------------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 962061dca05c..b590d93d054b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2029,7 +2029,7 @@ static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, unsigned long work_
  * try_to_grab_pending - steal work item from worklist and disable irq
  * @work: work item to steal
  * @is_dwork: @work is a delayed_work
- * @flags: place to store irq state
+ * @irq_flags: place to store irq state
  *
  * Try to grab PENDING bit of @work.  This function can handle @work in any
  * stable state - idle, on timer or on worklist.
@@ -2051,17 +2051,17 @@ static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, unsigned long work_
  * irqsafe, ensures that we return -EAGAIN for finite short period of time.
  *
  * On successful return, >= 0, irq is disabled and the caller is
- * responsible for releasing it using local_irq_restore(*@flags).
+ * responsible for releasing it using local_irq_restore(*@irq_flags).
  *
  * This function is safe to call from any context including IRQ handler.
  */
 static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
-			       unsigned long *flags)
+			       unsigned long *irq_flags)
 {
 	struct worker_pool *pool;
 	struct pool_workqueue *pwq;
 
-	local_irq_save(*flags);
+	local_irq_save(*irq_flags);
 
 	/* try to steal the timer if it exists */
 	if (is_dwork) {
@@ -2136,7 +2136,7 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 	raw_spin_unlock(&pool->lock);
 fail:
 	rcu_read_unlock();
-	local_irq_restore(*flags);
+	local_irq_restore(*irq_flags);
 	if (work_is_canceling(work))
 		return -ENOENT;
 	cpu_relax();
@@ -2344,16 +2344,16 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq,
 		   struct work_struct *work)
 {
 	bool ret = false;
-	unsigned long flags;
+	unsigned long irq_flags;
 
-	local_irq_save(flags);
+	local_irq_save(irq_flags);
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_work(cpu, wq, work);
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_irq_restore(irq_flags);
 	return ret;
 }
 EXPORT_SYMBOL(queue_work_on);
@@ -2410,7 +2410,7 @@ static int select_numa_node_cpu(int node)
 bool queue_work_node(int node, struct workqueue_struct *wq,
 		     struct work_struct *work)
 {
-	unsigned long flags;
+	unsigned long irq_flags;
 	bool ret = false;
 
 	/*
@@ -2424,7 +2424,7 @@ bool queue_work_node(int node, struct workqueue_struct *wq,
 	 */
 	WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND));
 
-	local_irq_save(flags);
+	local_irq_save(irq_flags);
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		int cpu = select_numa_node_cpu(node);
@@ -2433,7 +2433,7 @@ bool queue_work_node(int node, struct workqueue_struct *wq,
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_irq_restore(irq_flags);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(queue_work_node);
@@ -2503,17 +2503,17 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 {
 	struct work_struct *work = &dwork->work;
 	bool ret = false;
-	unsigned long flags;
+	unsigned long irq_flags;
 
 	/* read the comment in __queue_work() */
-	local_irq_save(flags);
+	local_irq_save(irq_flags);
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_delayed_work(cpu, wq, dwork, delay);
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_irq_restore(irq_flags);
 	return ret;
 }
 EXPORT_SYMBOL(queue_delayed_work_on);
@@ -2539,16 +2539,16 @@ EXPORT_SYMBOL(queue_delayed_work_on);
 bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
 			 struct delayed_work *dwork, unsigned long delay)
 {
-	unsigned long flags;
+	unsigned long irq_flags;
 	int ret;
 
 	do {
-		ret = try_to_grab_pending(&dwork->work, true, &flags);
+		ret = try_to_grab_pending(&dwork->work, true, &irq_flags);
 	} while (unlikely(ret == -EAGAIN));
 
 	if (likely(ret >= 0)) {
 		__queue_delayed_work(cpu, wq, dwork, delay);
-		local_irq_restore(flags);
+		local_irq_restore(irq_flags);
 	}
 
 	/* -ENOENT from try_to_grab_pending() becomes %true */
@@ -4105,18 +4105,18 @@ EXPORT_SYMBOL(flush_rcu_work);
 
 static bool __cancel_work(struct work_struct *work, bool is_dwork)
 {
-	unsigned long flags;
+	unsigned long irq_flags;
 	int ret;
 
 	do {
-		ret = try_to_grab_pending(work, is_dwork, &flags);
+		ret = try_to_grab_pending(work, is_dwork, &irq_flags);
 	} while (unlikely(ret == -EAGAIN));
 
 	if (unlikely(ret < 0))
 		return false;
 
 	set_work_pool_and_clear_pending(work, get_work_pool_id(work));
-	local_irq_restore(flags);
+	local_irq_restore(irq_flags);
 	return ret;
 }
 
@@ -4137,11 +4137,11 @@ static int cwt_wakefn(wait_queue_entry_t *wait, unsigned mode, int sync, void *k
 static bool __cancel_work_sync(struct work_struct *work, bool is_dwork)
 {
 	static DECLARE_WAIT_QUEUE_HEAD(cancel_waitq);
-	unsigned long flags;
+	unsigned long irq_flags;
 	int ret;
 
 	do {
-		ret = try_to_grab_pending(work, is_dwork, &flags);
+		ret = try_to_grab_pending(work, is_dwork, &irq_flags);
 		/*
 		 * If someone else is already canceling, wait for it to
 		 * finish.  flush_work() doesn't work for PREEMPT_NONE
@@ -4175,7 +4175,7 @@ static bool __cancel_work_sync(struct work_struct *work, bool is_dwork)
 
 	/* tell other tasks trying to grab @work to back off */
 	mark_work_canceling(work);
-	local_irq_restore(flags);
+	local_irq_restore(irq_flags);
 
 	/*
 	 * Skip __flush_work() during early boot when we know that @work isn't
@@ -5381,15 +5381,15 @@ static void wq_adjust_max_active(struct workqueue_struct *wq)
 
 		activated = false;
 		for_each_pwq(pwq, wq) {
-			unsigned long flags;
+			unsigned long irq_flags;
 
 			/* can be called during early boot w/ irq disabled */
-			raw_spin_lock_irqsave(&pwq->pool->lock, flags);
+			raw_spin_lock_irqsave(&pwq->pool->lock, irq_flags);
 			if (pwq_activate_first_inactive(pwq, true)) {
 				activated = true;
 				kick_pool(pwq->pool);
 			}
-			raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
+			raw_spin_unlock_irqrestore(&pwq->pool->lock, irq_flags);
 		}
 	} while (activated);
 }
@@ -5762,7 +5762,7 @@ EXPORT_SYMBOL_GPL(workqueue_congested);
 unsigned int work_busy(struct work_struct *work)
 {
 	struct worker_pool *pool;
-	unsigned long flags;
+	unsigned long irq_flags;
 	unsigned int ret = 0;
 
 	if (work_pending(work))
@@ -5771,10 +5771,10 @@ unsigned int work_busy(struct work_struct *work)
 	rcu_read_lock();
 	pool = get_work_pool(work);
 	if (pool) {
-		raw_spin_lock_irqsave(&pool->lock, flags);
+		raw_spin_lock_irqsave(&pool->lock, irq_flags);
 		if (find_worker_executing_work(pool, work))
 			ret |= WORK_BUSY_RUNNING;
-		raw_spin_unlock_irqrestore(&pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pool->lock, irq_flags);
 	}
 	rcu_read_unlock();
 
@@ -6006,7 +6006,7 @@ void show_one_workqueue(struct workqueue_struct *wq)
 {
 	struct pool_workqueue *pwq;
 	bool idle = true;
-	unsigned long flags;
+	unsigned long irq_flags;
 
 	for_each_pwq(pwq, wq) {
 		if (!pwq_is_empty(pwq)) {
@@ -6020,7 +6020,7 @@ void show_one_workqueue(struct workqueue_struct *wq)
 	pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
 
 	for_each_pwq(pwq, wq) {
-		raw_spin_lock_irqsave(&pwq->pool->lock, flags);
+		raw_spin_lock_irqsave(&pwq->pool->lock, irq_flags);
 		if (!pwq_is_empty(pwq)) {
 			/*
 			 * Defer printing to avoid deadlocks in console
@@ -6031,7 +6031,7 @@ void show_one_workqueue(struct workqueue_struct *wq)
 			show_pwq(pwq);
 			printk_deferred_exit();
 		}
-		raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pwq->pool->lock, irq_flags);
 		/*
 		 * We could be printing a lot from atomic context, e.g.
 		 * sysrq-t -> show_all_workqueues(). Avoid triggering
@@ -6050,10 +6050,10 @@ static void show_one_worker_pool(struct worker_pool *pool)
 {
 	struct worker *worker;
 	bool first = true;
-	unsigned long flags;
+	unsigned long irq_flags;
 	unsigned long hung = 0;
 
-	raw_spin_lock_irqsave(&pool->lock, flags);
+	raw_spin_lock_irqsave(&pool->lock, irq_flags);
 	if (pool->nr_workers == pool->nr_idle)
 		goto next_pool;
 
@@ -6081,7 +6081,7 @@ static void show_one_worker_pool(struct worker_pool *pool)
 	pr_cont("\n");
 	printk_deferred_exit();
 next_pool:
-	raw_spin_unlock_irqrestore(&pool->lock, flags);
+	raw_spin_unlock_irqrestore(&pool->lock, irq_flags);
 	/*
 	 * We could be printing a lot from atomic context, e.g.
 	 * sysrq-t -> show_all_workqueues(). Avoid triggering
@@ -7212,10 +7212,10 @@ static DEFINE_PER_CPU(unsigned long, wq_watchdog_touched_cpu) = INITIAL_JIFFIES;
 static void show_cpu_pool_hog(struct worker_pool *pool)
 {
 	struct worker *worker;
-	unsigned long flags;
+	unsigned long irq_flags;
 	int bkt;
 
-	raw_spin_lock_irqsave(&pool->lock, flags);
+	raw_spin_lock_irqsave(&pool->lock, irq_flags);
 
 	hash_for_each(pool->busy_hash, bkt, worker, hentry) {
 		if (task_is_running(worker->task)) {
@@ -7233,7 +7233,7 @@ static void show_cpu_pool_hog(struct worker_pool *pool)
 		}
 	}
 
-	raw_spin_unlock_irqrestore(&pool->lock, flags);
+	raw_spin_unlock_irqrestore(&pool->lock, irq_flags);
 }
 
 static void show_cpu_pools_hogs(void)
-- 
2.43.2