The patch titled
] core: workqueue: return on workqueue recursion
has been added to the -mm tree. Its filename is
core-workqueue-return-on-workqueue-recursion.patch
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------------------------------------------------------
Subject: ] core: workqueue: return on workqueue recursion
From: Simon Kagstrom <simon.kagstrom@xxxxxxxxxxxxxx>
When the workqueue is flushed from workqueue context (recursively), the
system enters a strange state where things at random (dependent on the
global workqueue) start misbehaving. For example, for us the console and
logins locks up while the web server continues running.
The system becomes unstable since the workqueue barrier locks the
workqueue. This patch instead returns if the workqueue is flushed
recursively, which keeps the workqueue alive but warns.
Signed-off-by: Simon Kagstrom <simon.kagstrom@xxxxxxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/workqueue.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN kernel/workqueue.c~core-workqueue-return-on-workqueue-recursion kernel/workqueue.c
--- a/kernel/workqueue.c~core-workqueue-return-on-workqueue-recursion
+++ a/kernel/workqueue.c
@@ -482,7 +482,8 @@ static int flush_cpu_workqueue(struct cp
int active = 0;
struct wq_barrier barr;
- WARN_ON(cwq->thread == current);
+ if (WARN_ON(cwq->thread == current))
+ return 1;
spin_lock_irq(&cwq->lock);
if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) {
_
Patches currently in -mm which might be from simon.kagstrom@xxxxxxxxxxxxxx are
linux-next.patch
core-workqueue-return-on-workqueue-recursion.patch
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