Re: [GIT PULL] workqueue fixes for v4.13-rc3

From: Tejun Heo <tj@kernel.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Michael Bringmann <mwb@linux.vnet.ibm.com>
Subject: Re: [GIT PULL] workqueue fixes for v4.13-rc3
Date: Mon, 7 Aug 2017 10:06:59 -0700	[thread overview]
Message-ID: <20170807170659.GB537256@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <CAMuHMdUOoKAB9RXWF3gkEf6m0ww1XrYWL6QGzV6ucLQuOX3rUg@mail.gmail.com>

Hello,

On Mon, Aug 07, 2017 at 02:18:51PM +0200, Geert Uytterhoeven wrote:
> This triggers on m68k, which doesn't have SMP.
> Haven't tried it yet on any other system due to holidays.

That's weird.  Can you please apply the following patch and report the
messages?

Thanks.

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ca937b0..1b9d21b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3579,8 +3579,10 @@ static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node,
 	cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]);
 
 	if (cpumask_empty(cpumask)) {
-		pr_warn_once("WARNING: workqueue cpumask: online intersect > "
-				"possible intersect\n");
+		pr_warn_once("WARNING: workqueue empty cpumask: node=%d cpu_going_down=%d cpumask=%*pb online=%*pb possible=%*pb\n",
+			     node, cpu_going_down, cpumask_pr_args(attrs->cpumask),
+			     cpumask_pr_args(cpumask_of_node(node)),
+			     cpumask_pr_args(wq_numa_possible_cpumask[node]));
 		return false;
 	}
 
@@ -5526,6 +5528,9 @@ static void __init wq_numa_init(void)
 
 	wq_numa_possible_cpumask = tbl;
 	wq_numa_enabled = true;
+
+	for_each_node(node)
+		printk("XXX wq node[%d] %*pb\n", node, cpumask_pr_args(wq_numa_possible_cpumask[node]));
 }
 
 /**
