workqueue: drop 'H' from kworker names of unbound worker pools (e3c916a4) · Commits · 戴 / test

Currently, all workqueue workers which have negative nice value has 'H' postfixed to their names. This is necessary for per-cpu workers as they use the CPU number instead of pool->id to identify the pool and the 'H' postfix is the only thing distinguishing normal and highpri workers. As workers for unbound pools use pool->id, the 'H' postfix is purely informational. TASK_COMM_LEN is 16 and after the static part and delimiters, there are only five characters left for the pool and worker IDs. We're expecting to have more unbound pools with the scheduled NUMA awareness support. Let's drop the non-essential 'H' postfix from unbound kworker name. While at it, restructure kthread_create*() invocation to help future NUMA related changes. Signed-off-by:

Tejun Heo <tj@kernel.org> Reviewed-by:

Lai Jiangshan <laijs@cn.fujitsu.com>

kernel/workqueue.c

+8 −7

Original line number	Diff line number	Diff line
		@@ -1644,9 +1644,10 @@ static struct worker *alloc_worker(void)
		*/
		static struct worker create_worker(struct worker_pool pool)
		{
		const char *pri = pool->attrs->nice < 0 ? "H" : "";
		struct worker *worker = NULL;
		int node = pool->cpu >= 0 ? cpu_to_node(pool->cpu) : NUMA_NO_NODE;
		int id = -1;
		char id_buf[16];

		lockdep_assert_held(&pool->manager_mutex);

		@@ -1672,13 +1673,13 @@ static struct worker create_worker(struct worker_pool pool)
		worker->id = id;

		if (pool->cpu >= 0)
		worker->task = kthread_create_on_node(worker_thread,
		worker, cpu_to_node(pool->cpu),
		"kworker/%d:%d%s", pool->cpu, id, pri);
		snprintf(id_buf, sizeof(id_buf), "%d:%d%s", pool->cpu, id,
		pool->attrs->nice < 0 ? "H" : "");
		else
		worker->task = kthread_create(worker_thread, worker,
		"kworker/u%d:%d%s",
		pool->id, id, pri);
		snprintf(id_buf, sizeof(id_buf), "u%d:%d", pool->id, id);

		worker->task = kthread_create_on_node(worker_thread, worker, node,
		"kworker/%s", id_buf);
		if (IS_ERR(worker->task))
		goto fail;

Admin message