From e3c916a4c7f51722785d34d9f9802b70dac3ce93 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Mon, 1 Apr 2013 11:23:32 -0700
Subject: workqueue: drop 'H' from kworker names of unbound worker pools

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>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5ca46a2..248d18a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -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;
 
-- 
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