Commit 24ca36a5 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'wq-for-6.10-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 

Pull workqueue fixes from Tejun Heo:
 "Two patches to fix kworker name formatting"

* tag 'wq-for-6.10-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Increase worker desc's length to 32
  workqueue: Refactor worker ID formatting and make wq_worker_comm() use full ID string
parents 55027e68 231035f1

include/linux/workqueue.h

+1 −1
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ enum wq_misc_consts { 
	WORK_BUSY_RUNNING	= 1 << 1,



	/* maximum string length for set_worker_desc() */

	WORKER_DESC_LEN		= 24,

	WORKER_DESC_LEN		= 32,

};



/* Convenience constants - of type 'unsigned long', not 'enum'! */

kernel/workqueue.c

+34 −17
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ enum wq_internal_consts { 
	HIGHPRI_NICE_LEVEL	= MIN_NICE,



	WQ_NAME_LEN		= 32,

	WORKER_ID_LEN		= 10 + WQ_NAME_LEN, /* "kworker/R-" + WQ_NAME_LEN */

};



/*
@@ -2742,6 +2743,26 @@ static void worker_detach_from_pool(struct worker *worker) 
		complete(detach_completion);

}



static int format_worker_id(char *buf, size_t size, struct worker *worker,

			    struct worker_pool *pool)

{

	if (worker->rescue_wq)

		return scnprintf(buf, size, "kworker/R-%s",

				 worker->rescue_wq->name);



	if (pool) {

		if (pool->cpu >= 0)

			return scnprintf(buf, size, "kworker/%d:%d%s",

					 pool->cpu, worker->id,

					 pool->attrs->nice < 0  ? "H" : "");

		else

			return scnprintf(buf, size, "kworker/u%d:%d",

					 pool->id, worker->id);

	} else {

		return scnprintf(buf, size, "kworker/dying");

	}

}



/**

 * create_worker - create a new workqueue worker

 * @pool: pool the new worker will belong to
@@ -2758,7 +2779,6 @@ static struct worker *create_worker(struct worker_pool *pool) 
{

	struct worker *worker;

	int id;

	char id_buf[23];



	/* ID is needed to determine kthread name */

	id = ida_alloc(&pool->worker_ida, GFP_KERNEL);
@@ -2777,17 +2797,14 @@ static struct worker *create_worker(struct worker_pool *pool) 
	worker->id = id;



	if (!(pool->flags & POOL_BH)) {

		if (pool->cpu >= 0)

			snprintf(id_buf, sizeof(id_buf), "%d:%d%s", pool->cpu, id,

				 pool->attrs->nice < 0  ? "H" : "");

		else

			snprintf(id_buf, sizeof(id_buf), "u%d:%d", pool->id, id);

		char id_buf[WORKER_ID_LEN];



		format_worker_id(id_buf, sizeof(id_buf), worker, pool);

		worker->task = kthread_create_on_node(worker_thread, worker,

					pool->node, "kworker/%s", id_buf);

						      pool->node, "%s", id_buf);

		if (IS_ERR(worker->task)) {

			if (PTR_ERR(worker->task) == -EINTR) {

				pr_err("workqueue: Interrupted when creating a worker thread \"kworker/%s\"\n",

				pr_err("workqueue: Interrupted when creating a worker thread \"%s\"\n",

				       id_buf);

			} else {

				pr_err_once("workqueue: Failed to create a worker thread: %pe",
@@ -3350,7 +3367,6 @@ static int worker_thread(void *__worker) 
		raw_spin_unlock_irq(&pool->lock);

		set_pf_worker(false);



		set_task_comm(worker->task, "kworker/dying");

		ida_free(&pool->worker_ida, worker->id);

		worker_detach_from_pool(worker);

		WARN_ON_ONCE(!list_empty(&worker->entry));
@@ -5542,6 +5558,7 @@ static int wq_clamp_max_active(int max_active, unsigned int flags, 
static int init_rescuer(struct workqueue_struct *wq)

{

	struct worker *rescuer;

	char id_buf[WORKER_ID_LEN];

	int ret;



	if (!(wq->flags & WQ_MEM_RECLAIM))
@@ -5555,7 +5572,9 @@ static int init_rescuer(struct workqueue_struct *wq) 
	}



	rescuer->rescue_wq = wq;

	rescuer->task = kthread_create(rescuer_thread, rescuer, "kworker/R-%s", wq->name);

	format_worker_id(id_buf, sizeof(id_buf), rescuer, NULL);



	rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", id_buf);

	if (IS_ERR(rescuer->task)) {

		ret = PTR_ERR(rescuer->task);

		pr_err("workqueue: Failed to create a rescuer kthread for wq \"%s\": %pe",
@@ -6384,19 +6403,15 @@ void show_freezable_workqueues(void) 
/* used to show worker information through /proc/PID/{comm,stat,status} */

void wq_worker_comm(char *buf, size_t size, struct task_struct *task)

{

	int off;



	/* always show the actual comm */

	off = strscpy(buf, task->comm, size);

	if (off < 0)

		return;



	/* stabilize PF_WQ_WORKER and worker pool association */

	mutex_lock(&wq_pool_attach_mutex);



	if (task->flags & PF_WQ_WORKER) {

		struct worker *worker = kthread_data(task);

		struct worker_pool *pool = worker->pool;

		int off;



		off = format_worker_id(buf, size, worker, pool);



		if (pool) {

			raw_spin_lock_irq(&pool->lock);
@@ -6415,6 +6430,8 @@ void wq_worker_comm(char *buf, size_t size, struct task_struct *task) 
			}

			raw_spin_unlock_irq(&pool->lock);

		}

	} else {

		strscpy(buf, task->comm, size);

	}



	mutex_unlock(&wq_pool_attach_mutex);