From 729d6a55cb8fa90fe5bc37b24ffda2afc2b0eb6c Mon Sep 17 00:00:00 2001
From: Petr Mladek <pmladek@suse.com>
Date: May 10 2023 14:34:46 +0000
Subject: workqueue: Warn when a rescuer could not be created

(bsc#1211044).

---

diff --git a/patches.suse/workqueue-Warn-when-a-rescuer-could-not-be-created.patch b/patches.suse/workqueue-Warn-when-a-rescuer-could-not-be-created.patch
new file mode 100644
index 0000000..86e7e53
--- /dev/null
+++ b/patches.suse/workqueue-Warn-when-a-rescuer-could-not-be-created.patch
@@ -0,0 +1,48 @@
+From 4c0736a76a186e5df2cd2afda3e7a04d2a427d1b Mon Sep 17 00:00:00 2001
+From: Petr Mladek <pmladek@suse.com>
+Date: Tue, 7 Mar 2023 13:53:34 +0100
+Subject: [PATCH] workqueue: Warn when a rescuer could not be created
+Git-commit: 4c0736a76a186e5df2cd2afda3e7a04d2a427d1b
+Patch-mainline: v6.4-rc1
+References: bsc#1211044
+
+Rescuers are created when a workqueue with WQ_MEM_RECLAIM is allocated.
+It typically happens during the system boot.
+
+systemd switches the root filesystem from initrd to the booted system
+during boot. It kills processes that block the switch for too long.
+One of the process might be modprobe that tries to create a workqueue.
+
+These problems are hard to reproduce. Also alloc_workqueue() does not
+pass the error code. Make the debugging easier by printing an error,
+similar to create_worker().
+
+Signed-off-by: Petr Mladek <pmladek@suse.com>
+Signed-off-by: Tejun Heo <tj@kernel.org>
+
+---
+ kernel/workqueue.c |    7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+--- a/kernel/workqueue.c
++++ b/kernel/workqueue.c
+@@ -4074,13 +4074,18 @@ struct workqueue_struct *__alloc_workque
+ 		struct worker *rescuer;
+ 
+ 		rescuer = alloc_worker(NUMA_NO_NODE);
+-		if (!rescuer)
++		if (!rescuer) {
++			pr_err("workqueue: Failed to allocate a rescuer for wq \"%s\"\n",
++			       wq->name);
+ 			goto err_destroy;
++		}
+ 
+ 		rescuer->rescue_wq = wq;
+ 		rescuer->task = kthread_create(rescuer_thread, rescuer, "%s",
+ 					       wq->name);
+ 		if (IS_ERR(rescuer->task)) {
++			pr_err("workqueue: Failed to create a rescuer kthread for wq \"%s\": %ld",
++			       wq->name, PTR_ERR(rescuer->task));
+ 			kfree(rescuer);
+ 			goto err_destroy;
+ 		}
diff --git a/series.conf b/series.conf
index fa2a90b..946ca81 100644
--- a/series.conf
+++ b/series.conf
@@ -63308,6 +63308,7 @@
 	patches.suse/workqueue-Fix-hung-time-report-of-worker-pools.patch
 	patches.suse/workqueue-Warn-when-a-new-worker-could-not-be-create.patch
 	patches.suse/workqueue-Interrupted-create_worker-is-not-a-repeate.patch
+	patches.suse/workqueue-Warn-when-a-rescuer-could-not-be-created.patch
 	patches.suse/xfs-verify-buffer-contents-when-we-skip-log-replay.patch
 
 	# dhowells/linux-fs keys-uefi