linux-kernel - [RFC 3/5] workqueue: Interrupted create

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Date:   Wed,  1 Feb 2023 14:45:41 +0100
From:   Petr Mladek <pmladek@...e.com>
To:     Tejun Heo <tj@...nel.org>
Cc:     Lai Jiangshan <jiangshanlai@...il.com>,
        Michal Koutny <mkoutny@...e.com>, linux-kernel@...r.kernel.org,
        Petr Mladek <pmladek@...e.com>
Subject: [RFC 3/5] workqueue: Interrupted create_worker() is not a repeated event

kthread_create_on_node() might get interrupted(). It is rare but realistic.
For example, when an unbound workqueue is allocated in module_init()
callback. It is done in the context of the "modprobe" process. And,
for example, systemd might kill pending processes when switching root
from initrd to the booted system.

Handle the interrupt a special way. It a one-off event in compare with
the other failures. Always print this warning. And do not block the other
warnings.

Signed-off-by: Petr Mladek <pmladek@...e.com>
---
 kernel/workqueue.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ab109ef7a7c0..5f3327e119b4 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1925,7 +1925,7 @@ void __print_create_worker_failure(long err, const char *fmt, ...)
 	 * touch watchdogs so that more frequent messages would prevent
 	 * reaching the watchdog thresh.
 	 */
-	if (!create_worker_failed) {
+	if (!create_worker_failed || err == -EINTR) {
 		va_list args;
 
 		va_start(args, fmt);
@@ -1933,7 +1933,8 @@ void __print_create_worker_failure(long err, const char *fmt, ...)
 		va_end(args);
 	}
 
-	create_worker_failed++;
+	if (err != -EINTR)
+		create_worker_failed++;
 
 	spin_unlock_irq(&create_worker_failed_lock);
 }
-- 
2.35.3